Zu Druid & Definition Roundup


In separate threads about the Zu Druid V and Zu Definition 3 & 4 in this forum, several questions have been directed to me about the comparative merits of these models, supertweeter capacitors, and a variety of other variables. Rather than bury comments in those threads, I thought it better to start a new thread and focus any follow-up comments or questions in one place.

Over the past few weeks, I helped a new Definition 3 owner install and setup his speakers, after earlier having setup his loaner Def3s that had an earlier iteration of the supertweeter network. Additionally, I made a capacitor change on the high pass filter to the supertweeter on my own Definition 4 and Druid V speakers. For further perspective on this, I have lived with my Definition 4 speakers for the past 13 months, and my Druid Vs for the past three months. Prior to that, I have migrated through the Definition 1.5 > 2 > 4 upgrade path, and Druid “3.5” > 4 > 4-08 > 5 upgrade path in two discrete systems since 2005. Any search on Zu topics or my handle here will serve up plenty of commentary on Zu speakers, cables, suitable amplification and other related matters, so I am not going to attempt to repeat all of that here. But I am going to roll up a collection of observations in response to prior questions, that might help Zu owners understand the relative value of current options in the upper half of Zu’s range, as well as people who have never owned Zu but who are considering their speakers, to better grasp what they might gain.

Druid 3, 4, 5

My first Druids were a used purchase from a prior owner here in Los Angeles. It turns out they were one of the first 10 pairs of Druids made. They had been sent back to Zu in late 2004 to be upgraded to then-current configuration plus had full internal Ibis cabling. The first 10 Druids made had the Speakon connector for full B3 geometry from amp to drivers when using Zu cables (I did), along with parallel Cardas posts for connecting any other cable. When I bought this first pair of Druids, they were shipped to me from Zu, in what Sean called a configuration he approximated as “version 3.5.” That speaker hooked me on the holistic Zu sound, but it had a euphonic warmth and soft top end that was forgiving and not fully revealing. Nevertheless, that v3.5 Druid was addictive for its unity of behaviors, and much like the original Quad electrostatic its ample advantages made it easy to overlook its limitations. The v4 upgrade opened up the top end marginally and was welcome, but the Spring 2008 v4-08 upgrade to Druid was a big leap toward bringing Druid closer to the liveliness and open top end of Definition. Then Druid was taken out of the Zu line. I let the Essence aberration pass by. Sean got back on track sonically with Superfly but I preferred the Druid form factor so stuck with the dead-ended Druid 4-08 for my secondary system, all the time lobbying Zu – along with other Druid owners – to restore Druid in more modern form in their line.

We got exactly that in Druid V late last year. For 4-1/2 years, while Essence came and went, Superfly got the HO FRD and then Nano, Druid was static and falling behind. Version 4-08 still had some tone-density and focus that was sacrificed in Superfly in favor of that speaker’s livelier, burstier dynamics and somewhat more expansive scalar projection. Superfly also had a slightly more extended top end than Druid 4-08 so to most people it simply sounded more like a modern speaker should, than Druid 4-08. It also had a more complete Griewe implementation, for faster and more textured bass than Druid. Druid V addressed all that, and more. The more advanced multi-composite cabinet with integral full Griewe and the mechanical grounding of the thick aluminum plinth would have comprehensively improved Druid even if the old Druid drivers had been installed. But the advance of the Nano FRD and the Radian 850 in supertweeter use gave us a Druid form factor speaker that has the linearity and finesse of Definition, with the traditional focus, unity and tone density of Druid even more present and obvious than in any prior version. Druid V *is* the modern equivalent to the original Quad ESL, without the extreme beaming, the bass limitation, dynamic restriction and fragility. It just happens to deliver Quad-like unity and speed from dynamic drivers with much higher efficiency *and* power handling. Druid V is finally an uncompromised and uncompromising speaker that despite its price can be justifiably driven by the very highest quality amplification at many times the cost of the speaker, yet can put modest amps in their best light. Why would anyone drive Druid V with amplification that costs lots more than a pair of the speakers? Because the total design can leverage stellar amplification, and no other speaker today can duplicate the full combination of attributes that Druid V delivers. You can get even greater focus and unity, ironically, in Zu’s line from the ~$60,000 Dominance, with its radiused front baffle and three FRDs, but not with Druid’s lightness of mass, presence and drivability. No Magico at any price can deliver Druid’s pure unity of behaviors regardless of what you try to drive them with, and no Magico is as musically satisfying with such a wide range of amplifiers. Druid V laughs at the cacophonous disunity of a Wilson speaker. Druid V ridicules the dynamic choke points imposed on Focal speakers at the crossover points. In the same way that no one appreciative of the unity of the Quad ESL heard any musical value from the Infinity IRS or a Duntech Sovereign back in the day, a Druid V owner today can pretty much ignore the rest of the alleged “high-end” speaker market inflicting damage upon our hearing, with the exception of other Zu speakers.

Because of the newest Nano FRD’s ability to reproduce more musical scale than prior Druids, for the first time in version V, Druid is a credible HT2.0 speaker in addition to being a great 2ch music speaker. Also for the first time, Druid is now quite good for listening to a full orchestra, whereas earlier Druids fell short on scale for orchestral purposes. Druid V is the first “no-apologies” Druid. That’s not to say that Definition doesn’t have advantages for more money – it certainly does. But Druid V is now a true all-music, all-purpose speaker with no real musical limitations in practical domestic use, and if a lower linear limit of about 35Hz isn’t deep enough for you, there’s always Zu’s new subwoofers. It’s also extremely amplifier-friendly. And the Griewe implementation does a fabulous job of extracting solid, tuneful bass from low-damping-factor/rising-deep-bass-THD SET amplifiers. Druid V gets qualitatively better bass from 2a3, 45 and 300B SET amps than any unassisted (no powered sub) speaker I can think of.

Definition 1.5, 2, 3, 4

The 2004/5 era Definition 1.5 was a revelation in its day, for its combination of speed, transparency, resolution, scale, bombast and finesse while having very good unity behaviors and terrific amplifier friendliness. It was sharply different from the same-era Druid because of its extended top end, almost tilted a little bright, and for its impressive sub-bass foundation. It was a relatively big, bursty, lively speaker even driven by modest power. It also had two clear deficiencies: first the sub-bass array amp had no level control (later and quickly rectified for everyone after I pointed out the glaring omission upon receiving my speakers), and second, that v1.X Definition’s MDF cabinet “talked” at high SPLs, marring the clean and incisive sound with an overriding glare. In Definition 2, cabinet talk was dramatically reduced by introduction of the birch-ply cabinet structure, stronger baffle, more robust plinth and associated damping techniques. The voicing of the speaker also tilted somewhat darker but the net result was a Definition absent ringing and glare, cleaner at moderate SPLs and far less fatiguing at high playing volumes – even fair to say altogether unfatiguing. While Definition 4 introduced many simultaneous improvements, Definition 3 shows clearly how much cabinet talk was left in Def2’s “silent” cabinet. Def3 starts with a Def2 cabinet and gets additional bracing and damping during the upgrade and it is plainly apparent when you first fire up Def3s after being familiar with Def2, that sound emerges from cleaner, quieter noise plane in the newer speaker. Def3, while retaining Def2’s 4x10” sub-bass line array on a rear baffle, gains seriously-improved deep bass by virtue of replacement of the Def2 plate amp and level control with Def4’s D amp with parametric controls. The Dominance trickle-down Nano FRD gives Def3 a close facsimile of Def4 performance from lowest response up to 10kHz or so, but Def3 uses the older-generation Zu supertweeter, which cannot begin to match the beauty, finesse and spray of the Radian 850 supertweeter used in the upper range Zu speakers. Def3 sub-bass performance is not equal to Def4’s but it is surprisingly competitive. In the Zu FRD range of roughly 38Hz – 12kHz, Def3 is very close to Def4, separated by clear differences in cabinet construction and internal configuration that give Def4 advantage as should be the case. As you get above roughly 8kHz, where the Radian 850 in Def4 begins to slope in, the upper range of the FRD in Def4 through the Radian’s exclusive extension on the top are in absolutely every way contributive to an elevated sense of musical fidelity and realism.

Definition 3 would be a market-wrangling speaker not surpassed at 3 or 4X its price if Definition 4 did not exist. But it does. As good as the new sub-bass amp and parametric controls are for the older 4x10” line array on the back baffle of Def3, the 4x10” rear-firing cones can’t load the room as evenly and deliver the incisive unity of Def4’s downfiring 12” driver. As closely as Def3’s Nano FRDs match the same in Def4, the completely re-architected cabinet of Def4 allows the drivers to perform with greater neutrality and freedom from distracting resonance. And the Radian 850 sprays the loveliest and yet most objective harmonic content of any tweeter I can think of today. The combined effect of Def4’s improvements over the Def2/3 design make it a compelling upgrade worth every penny to anyone who can afford its price compared to Def3, and yet the bargain roots of rendering Def3s from donor Def2s yields a speaker that is astonishingly great for its sub-$10K price and is necessarily limited in the number that will be produced. Notwithstanding that Omen Def is probably the peak value point in a two-FRD Zu speaker, for true high-end applications, Def3 is the high-discretionary-income value point and Def4 above it is the luxury alternative that nevertheless has no non-essential waste in its composition or price.

Definition 3 or Druid V?

I get this question privately from time to time: “For less than $2K difference, Druid V or Def3?”

These two speakers suit different priorities. Ask yourself the following:

1/ What is your application? That is, do you use your speakers strictly for 2-ch music or is your system doing dual duty for 2ch music and HT2.0?
2/ How important is the bass region between 16Hz - 35Hz to you?
3/ What are you using for amplification?
4/ What is the size of the space you have to acoustically load, and how far you sit from your speakers.
5/ What are your music listening habits, and what are the 3 - 5 sonic attributes you most value to feel satisfied?

There’s not a straightforward answer to this question, without knowing the above, but it’s easy enough for anyone reading this to self-sort. Druid V will give you focus, tone density, top end finesse and beauty that Def3 can’t quite match; Def3 will give you spatial & dynamic scale, deep bass foundation, resolution and horizontal dispersion that Druid V can’t equal. Overlapping both are the speed, agility, transparency and shove of the Zu Nano FRD. So, having the honest self-awareness to know what satisfies you most if your finances force a choice, will yield a crisp answer. If you can’t live with the trade-off, that’s your signal to save, and save, for Definition 4s.

Supertweeter Network Capacitors

Recently, there has been a lot of new interest in capacitor upgrades for the supertweeter high pass filter in Zu speakers, particularly the Druid and Definition. I have not been able to listen to all the available and oft-discussed options. My Def2s and Druid Mk 4-08s had Mundorf Silver-in-Oil caps. I had my Definition 4s built with V-Cap CuTF as an upgrade over the Mundorf. My Druid Vs were built with Mundorf Silver-in-Oil. In January, at Sean Casey’s recommendation, I had Clarity caps installed in both Def4s and Druid Vs. My Duelund capacitors are back-ordered (well, Zu urgently needed my pair for a more demanding customer), so I await them. I have heard Duelunds in non-Zu speakers. There are a few things I can say about capacitors at this stage, with more comments to follow as I put more contenders head-to-head.

1/ Every capacitor brand, formulation and composition brings specific attributes and a sonic signature. None are perfect. Not even Duelunds. You tend to think that what is best in current experience is as good as it gets until you hear something better. I can understand why someone feels ecstatic allegiance to Duelund caps, while at the same time appreciating why someone else prefers V-Cap TFTF or CuTF or some other alternative to them. For example, Sean Casey takes the position that Clarity caps bring 85% of Duelund’s sound quality to Definition 4 and Druid 5, for less than 1/3rd the retail cost. Elsewhere on this forum, another poster relates a conversation wherein Sean said something similar about the Audyn True Copper caps (90% for 10%). I haven’t heard the Audyn capacitors so have no comment right now. I will say that if Clarity is close to Duelund results, then both are a clear improvement over Mundorf Silver-in-Oil. The Clarity cap is both revealing and exceedingly smooth. But the case for Clarity (and by extension Duelund if Sean’s assessment holds) isn’t a slam-dunk compared to V-Cap CuTF or TFTF. There’s such a thing as too-smooth. This is reminiscent of the same disagreement I have with advocates of “slow” voiced SET amplifiers compared to the quick and transparent Audion SET amps that are so unlike most other SET brands. Some listeners are strongly attracted to a too-smooth representation. A lot of instruments have some harshness and rough texture in their output. The Clarity sands a touch of this off, just like (but less than) the round-sound old-school SET amp voicings some listeners favor. The V-Cap has more snap & tooth in its sound, but it is also less forgiving. I’m still in trial with a decision about whether to stick with Clarity or return to V-Cap CuTF or TFTF – as well as Duelund – pending. No, don’t bother assuring me that I’m going to love Duelund caps. Just consider me open to being convinced, but also not assuming a priori I will be.

2/ All of these exotic film caps take time to settle in. Clarity sounds great fresh but then they put you through a few weeks of meandering performance. They seem to be sensitive to temperature during the infant hours of use. We’ve had an unusually cold December and January here in Los Angeles, and I don’t use much furnace heat (you northerners and east coasters should see what people in SoCal consider a “furnace…”). A day of 64 degrees in my house sets breaking-in Clarity caps back a couple of steps. A warm day with internal temps in the high 70s pushes them forward. Then they go through a period of sounding beautiful on simple music, but shut down with congestion and blur on complex music. And then they start being reborn again to reassert their original convincing impression, and more. You have to be patient with any change.

3/ The Radian 850 in supertweeter application in Druid V and above in Zu’s line is intrinsically smooth, articulate, detailed and lovely. Frankly every cap sounds great into it, with the worst and the best still within the realm of excellent. You’ll hear differences and likely develop clear preferences, but even the basic Mundorf Silver-in-Oil sounds fully credible and completely acceptable in the absence of hearing something better. But the advantage of upgrading the Clarity (or Audyn True Copper, I imagine) is unmistakably beneficial to Def3’s supertweeter, and any earlier Definition or other Zu speaker using it, is fairly dramatic insofar as you are paying attention to top end harmonic character and are influenced by it. Clarity really tames much of the comparative roughness in the pre-Radian Zu supertweeter, compared to all the stock cap choices put in those speakers. What I’m saying is, pick your cap for Def4 and Druid5, knock yourself out. Some will sound definitely better but all will sound very fine. But if you have a Zu speaker using the older supertweeter and have an appetite to give them a worthwhile refinement, get a Clarity cap network upgrade. The cost is very reasonable and the benefit is disproportionately large at the price.

4/ There may be a cheap sleeper in capacitors. I was discussing film cap upgrades with Bob Hovland a couple of weeks ago. He mentioned that his more recent research indicated that the material consistency of the dielectric in film capacitors (even thickness & density, absence of pinholes) is more influential to sound quality than specific materials themselves. He wasn’t suggesting that all more exotic capacitors might not deliver someone’s preferred sound, but he does believe an excellent sounding cap can be made from prosaic materials. SuperCaps has a relatively new family of “Robert Hovland Edition” film caps that are highly affordable. They are handmade in the US, comprised of non-exotic materials, highly inspected during build and sealed tightly. I got some samples from Bob to try in my tube-output DACs and the results exceeded my expectations by a wide margin. They are more than good enough to settle on, and are staying in the DAC (mhdt Havana Balanced). He is next very eager for me to try a pair of 1uF/1000v versions in my Zu high-pass networks. I don’t know what to expect relative to Mundorf, Clarity, Audyn, Duelund but it’s a trial too interesting to not undertake. I’ll post back results, perhaps after I can put Duelunds in the mix, too.

Enough for now. I’m happy to add comments if questions are posted. I am sure I will remember something I intended to write here, but forgot.

Phil
213cobra

Showing 42 responses by 213cobra

>>To ad to Charles's thought, adding an additional chassis should raise production costs in itself.<<

If everything else is the same, yes. But if the collective power supply components are smaller and less costly, there may be net savings.

I bought, direct from Audion, what were claimed to be the last two Black Shadows produced at that time. The amps were announced discontinued with a replacement coming "soon." This was during the time Audion was changing from steel to aluminum chassis for the whole line, with an easier-to-build design and somewhat more contemporary aesthetics and improved interior layouts. When the new 845 amp was released, it was the three box Elite. For awhile, Black Shadow was represented as no longer in production, though there were hints that it might be possible to get a special order pair built. Interestingly, Golden Dreams, steel chassis and all the rest, never left the catalog.

After another change in US importers, the current agent advocated for restoring the monoblock pairs configuration and I was aware people elsewhere around the globe wanted it back, too. the Black Shadow was reborn. I assume the Elite version remains in the line as long as build stock exists, given the slim $1500 difference. There's no other reason I can see to keep it at such a relatively small savings over Black Shadow monoblocks.

Phil
Spirit,

The only changes I made to my Black Shadows were 1/ tubes, and 2/ recapped the power supplies with Nichicon. Bob Hovland did the work, but he and I both agreed on Nichicon because our mutual experience was that when caps are similar rating and materials, taller/thinner proportions tend to sound "faster" in discharge/recharge. We got what we anticipated, and then some.

It's only recently that Audion offered (at least promotionally) the Golden Dream "Levels" on Black Shadow. Level 5 Black Shadow has silver signal path wiring. As you pay for progressively higher levels of execution, you get upgraded caps (I think Audion still has a stash of Black Gates, for example, and I think Graeme will take any spec right up to Duelund) at progressively higher prices. You can also proceed up the ramp of silver content: from silver signal path you can add silver wound output transformer secondaries, then primaries, then full silver even in the power transformers.

Is it worth it? My Golden Dreams are Level 6. I'd say yes. I will probably wait for any upgrade there until I can drain the bank for a $36,000 pair of Golden Dreams Level 9.

When I was running the company, I commissioned my tech team to develop and build the Seymour Duncan Zephyr silver coil guitar pickups. I had a pair of identical test bed guitars built from the same board, body and neck, so we could play a reference pickup and a design change in direct comparison.

I knew from my Audion amps that the sonic value of silver in coils was far more uniformly favorable than silver in cables. Guitar players were skeptical, citing the relatively small conducting difference between copper and silver. But the first listening and playing test of silver against copper on the same bobbins and installed in the two identical guitars made the burstiness, responsiveness, frequency range and tone density of silver pickups immediately obvious to everyone. Vibrant, tone-drenched copper of the same pickup design sounded suddenly dull and truncated by comparison.

There was a lot of fear among my staff that silver would amount to a "hifi" pickup. "Hifi" is a perjorative in the distortion-oriented electric guitar world where amp designers generally don't want anything over 4kHz coming out of the speaker, unless it's for an acoustic guitar amp.

I didn't think sterile, wideband, toneless, hifi sound would be the result and it wasn't. People who thought that were extrapolating their experience with silver guitar cables. Not the same thing. In coils, I have always found silver to improve clarity, speed, transient shove and tone-density all at the same time. Interestingly, what silver pickups did for intentional guitar distortion was to make it richer, more expressive and harmonically more complete. My tech team found some other contributing synergies in using glass-fiber-nylon for the bobbin, machining bi-metallic pole pieces, and then we tested another hifi practice -- cryogenic treatment. Every change was play-tested in isolation. So, for example, cryo improved a stock copper pickup in the same way it improved silver.

A few professional players who live with pickups for a generation returned a verdict: best pickup they ever heard.

Downside, they're damned expensive, so limited in appeal. But they are worth the price for any player who can afford them. Having worked through the economics of building a tiny guitar pickup around silver, I easily appreciate how amps in distribution can get expensive so quickly as silver content heads toward the full coil and wire package.

If I were buying Black Shadows today, I'd go as high in Audion's "Level" scheme as wallet allows, and not look back. If you already understand the Black Shadows as I do, then however high you buy into, it will be all good.

Phil
Marc,

The initial "Mk 2" Audion Black Shadows were transitional and didn't have new nameplates. With some further work, the full Mk2 shipped with the nameplates, and in Audion parlance, these became "'Mark 2, Mark 2."

What you have is excellent in its own right; don't worry about it.

Phil
>Guys, does anyone have any experience of running a TVC passive pre, either with the Zu's, or generally? My Audion SET amps dealer is a massive fan of them, but prevailing opinions esp Phil 213Cobra, maintains it's a misfire.<<

It's not bad, but not as good as it should be. I used an S&B-based TVC with Audion Golden Dream monoblocks for a couple of years, and it was clearly better mated to that amplifier than to the Audion Black Shadow. I had three different TVCs through my systems and found this to be consistently so. I couldn't explain it on input stage impedance specs alone.

On the other hand, the TVC is a great match to Quad II monoblocks. With all the Audion SET amps I've owned, a well-selected active preamp easily trumped a TVC, except with the Golden Dream 300B PSET amps, in which case, the TVC has some advantages in immediacy if not dynamics.

My TVC is on a shelf. It's my backup preamp. I returned active preamps to both systems.

But try one. It might float you.

Phil
>>I would hate to swap out what is evidently a good all rounder to replace with something much more program dependent. Any thoughts on this? And is your Duelund experiment going to stretch to the CAST Cu, or the Sean-recommended VSF Black?<<

As I wrote earlier, on the Radian 850, none of the caps I discussed sound less than excellent. There is nothing wrong with the Mundorf silver-in-oil. Sean Casey was in Los Angeles delivering a pair of Def3s to a customer when he stopped by to see me and we spent the better part of a day noodling with cap changes and listening to a wide variety of music, while discussing the results. I ordered some Duelund caps from him but they got diverted to another, noisier, customer so I didn't have a chance to listen to them at that time.

In listening to the three caps we had on hand that day -- Mundorf silver-in-oil, V-Cap CuTF, Clarity MR -- none of them had advantages restricted to any type or genre of music. Clarity is of these three most forgiving of poor recordings. They are all applicable as "all-arounders." The Mundorf is really very transparent and it can slightly accentuate roughness in a voice that's close-mic'd, or in a brass instrument, for example. Whether that's accurate or not depends on how much you know about the recording and the performer. On Leonard Choen's "Old Ideas" for instance, with the Mundorf and V-Cap the rasp in Leonard Cohen's voice is accentuated compared to the Clarity MR, where it's fully present but a little polished and recessed. To Sean Casey, the Clarity's rendition sounds more "right." I'm still evaluating but I'm leaning to the V-Cap's voicing being more natural, even if the Clarity's is subjectively more agreeable to the ear.

To most people these cap differences will seem quite subtle. We who really make something of them are hard core; admit it.

I'll also repeat: no matter what anyone says, none of these caps are completely neutral. Caps are invariably a choice in voicing, as much fixed parametric tone and voicing controls as are cables. I think there is a generally-agreeable hierarchy, and for Sean it's Mundorf SIO on bottom and Duelund on top, with Clarity, V-Cap and Audyn offering specific performance-per-dollar increments in between. Keep this up and we'll need next versions of our speakers to have some kind of quick change arrangement for the high-pass network caps!

I don't hear anything in ClarityMR that I consider "program dependent." If you listen to music with a lot of intentional distortion, Clarity will recess some of the sawtooth nature of it while keeping it present, whereas V-Cap will do nothing to polish it and will put just a touch of spotlight on it. Clarity gives a little more harmonic grace and beauty up top; V-Cap a little less so but in exchaange you get more snap. Mundorf is more like V-Cap in this respect, with the added difference that it sounds more "excitable" as SPLs rise. Comparatively, the Mundorf shows less grace with rising complexity and volume. While the Radian 850 reveals with finer nuance the differences between caps, than the older Zu supertweeter, the benefit of Clarity over Mundorf is much more material to the older Zu supertweeter in Def2 & 3. In Def4 and Druid5, the upgrade is a choice. In Def2 & 3, it sounds essential to me.

I won't blindly comment on Duelund in Zu until I try them. I've heard Duelunds in other speakers' crossovers and they were upgrades but also diluted by the nature of a multi-drivers/multi-way speaker. They are expensive and the company is erratic on delivery, since it is essentially a craft shop. Doing these cap comparisons in Definitions and Druids is highly inconvenient, so maybe I'll just go straight to trying CAST when I have (or take) the time. But Sean's take is that Clarity improves his speaker in the same direction that Duelund does, just not quite as far. If that is true and you want to upgrade for less than the cost of Duelund, then my recommendation is to go with Clarity if you (slightly) value smoothness over texture, and to go with V-Cap CuTF or TFTF if you (slightly) value texture over smoothness. If that's too difficult a choice to resolve then forget about all this and stick with your stock cap. It's just fine.

Phil
>>I'm curious how a Berning ZH230 amp would sound with the DruidV?<<

The Berning should sound fast, transparent and controlled on Druid V. I beleive the ZH230-12 Class A monoblocks will sound even better, and more sublime. That amp maintains its power into 16 ohms. It doubles 8 ohm distortion performance into 4 ohms, so with Druid you are off the impedance centerpoint in the right direction. The high damping factor (for a tube amp) should complement the very good bass control already imposed by Druid V's full Griewe implementation, for which the acoustic impedance can be adjusted at the floor gap. The high damping factor in the amp should let you adjust the floor gap a little high, to optimize for bass extension from the Druid, while sharply limiting the added bloat that would normally accompany that tuning.

Phil
>>Most vitally, a slight stridency in upper frequencies is replaced by a mild hint of smoothness which really allows extra levels of info to be revealed. This is not at all at the expense of excitement or involvement, it's an even more addictive cart than before. If you have a spare Zu 103, I really urge you to consider the mods.<<

Spirit,

My skepticism about this remains, in part because you refer to your stock Zu103 having had stridency in the upper frequencies. If you had stidency in a Zu103, something was amiss, and it could have been any of several things. So your post-surgery comparison to the stock baseline is hard to reconcile.

Now, I have no doubt that with a sapphire cantilever and Paratrace stylus you are gaining resolution of all kinds over the stock 103, and that may have been exactly what you were looking for. But substituting sapphire where there was aluminum, and a Paratrace profile where there was conical, will revoice a cartridge. It's unavoidable. I don't doubt you like your result, however. I might even prefer it! But it's going to be different and if that's the case, I then wonder whether I'd be better off going for a 47 Labs MC Bee. That's what I have to think about, since the Zu103 is what it is, intentionally.

However, by all accounts, ESCO is highly competent so like Soundsmith I highly regard their work and they offer sensible modernizations that can turn out well, as yours has for you.

Phil
>>Phil,any revised thoughts on the SIT-1 amplifiers with further listening?<<

No; SIT-1 is a dead end. Great tonality, body & speed for solid state. Closer to realism than anything else silicon I've ever heard. But while bass character & texture are stellar I agree with Keithr -- the bloom on the uptick and the desiccated decay are inconsistent & distracting if you've lived with better. Sean Casey, who has heard the alleged magic of a DHT preamp into SIT-1s felt my various tube preamps do a fine job of driving the SIT-1 for valid evaluation. I didn't have even a few seconds of desire for SIT-1 over any of my Audions. Best SS is a benchmark but it doesn't elbow the Audion SETs, so what's the point? Then the dynamic limits quash any edge SIT retains. Sure, if someone stipulates they have to own SS or need absolute quiet, I'll suggest SIT-1 monoblocks as best alternative for them. Because with Zu they will be. But absent such stipulations (I have no reason to eschew tubes, and a little noise isn't my chief worry in life) a small minority of fast, transparent, toneful SET amps will yield more natural, holistic results. SIT-1 interest is now in my rear view mirror. Next topology challenger?

Phil
>>...comparison of the Essence, which I have had for 3 months, and the Druid Mk V...<<

I have had Essence in my Druids system. The Druid V will be a huge upgrade, but essential differences are easy to outline. As anyone who read my prior postings on Essence will know, I consider that speaker the "least-Zu" Zu speaker though for that reason it appealed to the market and did its job of widening Zu's appeal. I'll limit my comments here to the sonic traits. For Essence, Zu had to detune the Zu FRD to scrub out some of its shove and efficiency to match the ribbon supertweeter. For Druid V they did not have to do this, as the nano FRD and the Radian 850 are much better mates. So all the trademark burstiness, liveliness, 101db/w/m efficiency and shove that were truncated in Essence are back in Druid V, as they are in Superfly, also a post-Essence single FRD Zu speaker.

The harmonic completeness of the Radian 850 also far surpasses Essence's ribbon, and gives Druid V greater top end beauty and absence of fatigue. The Nano FRD and the Radian's dynamic and solution traits are also better matched, for much better unity of behaviors over the older, less expensive Essence. Overall speed and scale are upgraded comprehensively. And while Essence had the first full implementation of Zu's Griewe acoustic impedance loading scheme in a single FRD speaker, both Superfly and Druid V incorporate further refinements, so bass texture, definition, energy and quality of tone are better.

Just mind the floor gap. Essence fixed the setting with it's double plinth. With Druid you have some work to do, and very small changes yield significant differences.

>>...it's all on your shoulders, Phil...<<

Not for the first time. If you get the Druid V and have any anxiety during break-in, post here for group experience or private-message me with questions; or call Sean. I am sure you will be pleased however, pretty much out of the box.

Phil
>>What are you thoughts on the merits of Druid V with a pair of Submissions vs. Def4's?<<

The choice here will be made in a variation of the trade-off between Druid V and Def4. Running stereo Submission subs will give a more massive sub-bass foundation than Def4, so if you have a large space to fill or strongly prefer structure-permeating deep bass even if mid-range scale is smaller, or if you want monster available deep bass energy with Druid's focus and immediacy over Def4, then Druid V + stereo Submissions is a tenable combination for similar dollars as Def4. Some of the people I have corresponded or spoken with about this choice may choose the Druid V path because they literally want to energize a house and are more concerned with social or party performance than focused listening.

But for the main music band of, say, 50Hz - 12kHz, the FRD arrangement is the determinant of scale vs. focus. If you want spatial scale and a higher dynamic ceiling along with greater sheer resolution, then no question Def4 is the better choice. If you want precision, intimately-focused imaging, scary-good guitar tone, and a bias toward warmth over scale, then Druid + Submission.

So, that's the balance of factors you have to think about. It's not my intent to discourage subwoofer sales at Zu. People who demand the bottom octave foundation Submission delivers are going to get it, and it's the right solution for that. I don't know of any non-Zu subs that mate well to the Zu FRD. However, my personal view is that Druid V particularly should be used unaugmented by a pair of subs. Its natural bass quality is so high and so much in continuity with midrange performance that I don't want the distraction -- and dilution of that integrity -- imposed by outboard subs. I think Superfly or Omen Def are better anchors for a system incorporating subs, and any future Zu model that gets inserted between Druid & Definition will be too.

Meanwhile, Definition 4 has excellent bottom octave presence. And its sub-bass section's upper end seamlessly mates to the FRD, subject to the user's judgment on the parametrics. It is the standalone full-range, scaled music solution for most environments. Omen Def, with dual FRDs, does a good job of matching midrange scale to Submission ambition for structure-permeating bass as adjunct to a Zu Griewe speaker having a lower limit around 34 Hz. That's how I see this.

Phil
>>Anyhow, I shall drop you a line soon. We'll need to have lunch or something.<<

Hugh,

Just ping me when you have time. Being 70 miles apart should be easy but we have the entire breadth of the LA metro between us, complicating rendezvous.

I've been catching up after a busy 2012. I just submitted my commentary on my Melody Pure Black 101 preamp in the Preamps/Amps forum for posting.

Phil
>>Could I also inquire as to a little more clarity or comparison regarding the "focus" as pertains to Druid vs Def/Message?<<

This is difficult to answer for a general audience, because I don't want to magnify or overstate the difference, yet I do want people who are interested to understand it. OK, try this: Definition/Message/Omen Def are IMAX Digital at your stadium-seating multiplex. Even if you're alone, it feels like a group experience. Druid V is a personal screening of a 35mm fresh film print, plush and organic, with some of the sharper details sanded slightly smoother in exchange for a seamless continuum in color tone. Even if others are with you, it feels like watching something intended for your eyes only.

Definition and Message have higher...well...definition. But their presentation of a performance doesn't seem quite as personally and singularly directed to you as with Druid. On the other hand, Druid's personal experience doesn't wash over you with tidal wave of sound like Definition and its dual-FRD relatives.

There's also the small but discernible factor that two of something never behave with quite the absolute unity of one of the same thing. But Definition's benefits from the dual FRD M-t-M arrangement outweigh the small sacrifice in absolute unity, so it is for most circumstances the more convincing speaker, at higher cost.

This trade off between focus and scale in the Def/Druid comparison has narrowed considerably with Def4/Druid V. It was a big difference previously. But Def4 has more range downward in its scalar characteristics, and Druid has more range upward in scalar presentation, than prior versions of each. In the Def3/Druid V comparison, it's also a narrower difference than Def2/Druid4.

Before writing this, I made a point of listening yesterday for a few hours to bigger, more bombastic music on Druid Vs, that I usually play on my Def4s. Druids had no trouble exciting me with the energy of the music. They stepped-up nicely, cranked. So it's not a stark choice that denies you one thing to get another. I also played smaller scale music on Def4s that I usually play on Druids, and Defs didn't force bigger-than-life sound on the performer.

Phil
>>Would you care to comment on the Soul Supreme vs. Druid V?<<

Soul Supreme is Soul with the Nano FRD, and the Radian 850 in supertweeter dutiy, just like Druid V. It also has the Speakon connector, so with Zu cable, full B3 can be extended to the amp outputs. Soul Supreme costs $1000 less than Druid V in the US, so you can imagine the two are not quite the same.

Soul Supreme is a smaller speaker. Not surprisingly, Soul Supreme sounds smaller than Druid V. It also does not have Druid V's massive machined aluminum plinth, so it sounds a little less "grounded." Soul's center of sonic gravity is a little higher. Additionally, the cabinet has less internal treatment so it contributes some measure of cabinet talk that Druid V silences. And Druid V's Griewe acoustic impedance loading scheme is more sophisticated and complete than Soul's, so Druid V's bass is more agile and controlled.

The two speakers have the same essential voicing, but these differences are genuine. Soul is nominally the higher value-per-dollar product because it has the essential benefits of the Nano FRD + Radian 850 + B3 + Griewe in a smaller, easier-to-produce and lower-materials-cost package. But for anyone willing the pay the price difference, Druid V will be the higher-finesse speaker, and the one I think closer to the preferences that led you to Harbeth after owning the original Superfly. And for that Druid V is the better bang-for-the-buck speaker for you.

Phil
>>have you had any reliability issues with the KR 300b tube<<

Nope, not a thing. I've never had a problem with either KR Enterprise or the current KR Audio 300B tubes. They can be a little noisy for the first 50 hours or so as they burn in, but that disappears and they get quiet, dynamic, detailed and toneful. They are very illuminating in Audion and other 300B amps I've listened to them in, with the best bass of any 300B tube I've used over the years.

I think Blume isn't using it because of the cost. They have risen quite a bit over the past decade. No one makes it their stock tube except KR for their electronics. The Coincident amps would have to cost more if stocked with KR.

The prior KR Enterprises company from Dr. Kron's days made reliable 300B tubes but I think the current KR Audio 300B sounds a little better. The older tubes were dialed more to impact and definition and less to tone. I think the current tube is more centered in that continuum. I have a quad of NOS KR Enterprise tubes and I suppose on close inspection I can see some more meticulous workmanship in tubes built when Dr. Kron was still alive, but this has not translated into any difference in reliability that I've experienced. These tubes are at least on par with Emission Labs and EAT 300B, which are also excellent, but the KR Audio is the "fastest."

How it compares to your Takatsuki, I can't say. But I've heard the KR 300B against everything else relevant and comparable that I can think of and I have no hesitation to recommend it. I prefer the KR to the modern-production Western Electric and the Shuguang re-issue of same, for instance. One notable exception: I haven't heard the Sophia Royal Princess yet. KR Audio offers the 300B in both globe and coke bottle glass. They sound subtly different, but both have the essential KR traits of speed, discipline, definition and bass control with convincing tone.

I say this all with some conviction, since my Golden Dream monoblocks are PSET and require 4 300B tubes, total -- which means there are some pretty decent amps that cost less than my Golden Dream power tubes.

Phil
>>have you heard the KR 845<<

I have. The KR is an "out-of-spec" 845, really KR's idiosyncratic take on the tube. It sounds fast, clean, linear and extended. Bass is deep but somewhat leaner than the 845B, at least in my Audions. Other circuits may vary. The top end is quicker than the 845B and sounds somewhat more extended. Midrange isn't as meaty tonally but it is clean and pure. The KR sounds spatially big and trades away a little shove in favor of more nuance, than the B tube.

The first few years of the KR845's production were rocky. KR put a ribbon filament in their 845, and poor production tolerances let to filament shorts in the field, resluting in some spectacular failures. So I had avoided that tube. It's also gotten much more expensive over the past six years or so. KR believes they have solved the reliability problem, and I certainly can't say they haven't. Reports of failures seem to have abated quite a lot. The owner of Audion says the KR is a drop-in replacement for Black Shadow and Elite amps, and it's his favorite tube for them, for example. He's had no trouble.

However, the filament current draw is different from 845 spec, so depending what amp you are using, you may need to make a component change in the filament supply to be sure of reliable operation, particularly for the amp. Ask the maker. BTW, if you have an 845 amp that uses the tube conservatively, you may be able to get many of the KR benefits from the Shuguang 845C sheet-metal-plate tube. But its dissipation rating is only 70w against the RCA spec of 100w, which the B conforms to (dissipation, not power). If you put it in an Audion amp, for instance, the 845C mildly "cherrys" but doesn't go runaway. It's tolerable but will shorten the life of the tube. The 845C also has an extended top end and crystal clarity, but in some amps, like mine, also is decidedly bright.

If you're interested in the KR845, two other upmarket priced tubes might also be interesting. The very limited production, scarce, and difficult to buy Elrod 845 is reputed to be unbeatable. Last I saw they are $1800/pr., with a long wait. For less than half that, the new Sophia 845 Mk III is gaining traction as a premium 845. I haven't heard it yet.

Of course at the prices of the top-of-market 845 tubes, you have to consider NOS RCA, United or GEs. They are still available though perfect pairs can be $1600 - $2400.

Phil
Definition 4 is an 8 ohms load speaker. Yes, you can drive it easily with 2, 4, 6w but that doesn't mean you will get the full dynamic life that's both convincing and possible from more power. It's not a "problem" running small wattage from an efficiency and loudness level, but you are not going to get all the drive and shove that a Zu speaker is capable of with small output triodes. "Singing" and showing the truer burstiness of real music dynamics are not the same thing. I started out with 8/8w on Zu back in 2004. I've also heard them with 1200w McIntosh mono amps, where the advantage was that a lot of sound could be derived from the first couple of Class A watts, but the unlimited headroom brings clarity that tiny amps don't deliver. It's not an average SPL level, it's energetic clarity. On a 6w amp in a sizable room, you're going to hear the dynamic limits of the amp, even on a 101db/w/m speaker. Remember, that's 101db/w/m -- as in @ 1 meter distance. No one is listening at 1m.

This power requirements thing is an easy thing to pencil out and convince yourself that a handful of watts will be fine. It can be beautiful. But when you compare it with the drive and shove of a big glass triode @ 20-25w, the effortlessness and clarity of nano-duration peaks at satisfying levels makes it hard to return to flea power. You end up with the experience Morgan has articulated. For Definitions or any of the Zu dual-FRD speakers specifically, the synergy between Zu + 845 SET is breathtaking for the twin deliveries of musically convincing shove and tone.

I have to point out that a Sonus Faber's 90+db/w/m efficiency argues for the sufficiency of a 50/50w amp, but that in fact sounds woefully inadequate after you've heard their speakers on equal-clarity high power. This is consistently true for other 90db/w/m speakers too. The trick is finding equal-clarity high power. Zu's extra 11db of efficiency means you can get that and it's effects at 25w SET.

Phil
>>...one of the speakers is framed in by a wall and not the other speaker, (no wall and very open space/ we're talking 12foot ceiling) would that still require the same low pass filter setting on both speakers?<<

You will want, in that case, unity in the hinge point for both speakers, but may require a lower level setting for the speaker closely bounded by a wall. You also might find some advantage to a different PEQ gain level in such a circumstance, but the PEQ frequency is likely best set the same on both speakers.

Phil
>>Magico/Constellation Audio sounded better at the last HE show than Zu/Audion- admittedly under show conditions and in different rooms<<

No kidding. Uh...the Zu room was absent anything more than casual (and asymmetrical) setup, and the source was a Zu-modded Technics SL1200 with an Audiomods Rega-derived tonearm and $695 Zu cartridge.

The Magico/Constellation sounded different, that's for sure. And all the annoying crossover traits were loudly present and accounted for. As was true for Focal, Wilson, Vandersteen et al. Imagined flat response didn't make up for it.

Audio Note has 2-way speakers designed for corner placement, with a designer's highly idiosyncratic voicing. That's a polarizing sound and one that isn't accommodating of a wide range of musical genres. It neither represents the widebander & crossoverless Zu approach nor the highly-engineered multi-way and crossover-intensive Magico.

There *are* comparatively well-executed crossover-based speakers. There *are* comparatively badly-executed crossoverless widebanders. Nevertheless, designers of crossover-intensive speakers have been unable eliminate crossover sound, whereas wideband crossoverless designs have improved dramatically and quickly, so that frequency deviations are now quite small and usually in domestically favorable ways. No speaker is linear in actual use. In fact I will go further and say that the crossover artifacts are becoming *more* apparent, not less, as drivers and systems become steadily more resolving -- including resolving that problem. If crossoverless designs hadn't gotten so much better in the last decade, I'd still be listening to crossover-based speakers, too. But now I don't have to, and none of the rest of Zu owners are either.

EVERY speaker requires careful amp matching to get the best performance from it, if you are chasing convincing musicality rather than confirmation of anechoic measure.

When you hear Zu's Dominance, you will understand how laggard Magico really is.

Phil
>>...but within the first hour of listening to the Audions I heard a "phasey" annoying brightness on certain piano recordings...<<

Jordan,

Not surprising. I have to ask: Are you driving your amps directly from your DAC? The tubes selected for the Black Shadows you bought presume a preamp as the feeder. I'll wait for your answer to say more. But overall you can expect some inconsistent anomalies from the 845Bs when they are brand new, including a short period of noisiness.

It's also worth investigating how your system responds to altering the gain relationship between the driving source and the power amps. Since you have 0.7v input sensitivity, almost anything before the amps with a volume control will work better with the amp inputs dialed back. In the case of a strong preamp, the amp input level controls would be quite attenuated. I generally prefer to use as much of the preamp gain as possible and minimize SET noise by running the amp inputs dialed back. With the Melody preamps, the Audion input levels are only at 9 o'clock. With lower gain preamps they'd be around the noon position. In any case, optimizing the distribution of gain for both noise and sound is worth exploring, as it can fine tune how the input section of the amps respond to what's incoming.

In general, I find Audion amps, though they have the input sensitivity to be *easily* driven by even a weak output source, to sound more authentic driven by a tube preamp. The 845 amp doesn't even get along with a TVC as well as Audion's 300B SET and PSET amps either. It's OK with a TVC but by contrast my Golden Dream amps are synergistic with a TVC. However, the choice of input tube can mitigate source-drive traits if you choose not to run a preamp, and the 5687/ec182cc driver has a lot of leverage on tuning the aural properties of the power tube. You only have three tubes to roll, but that's a tidy triplet of indices for bending sonics to your satisfaction cues.

Phil
>>Input tubes on the BS's are the Amperex White Label 6922 (I think?).<<

Against type, Sean tubes Audions for some reticence. All of the Amperex 6922s are quite nice; beautiful sounding, really. But they are polite and smooth, not vivid and dynamic like the Siemens, Siemens-Halske and Valvo e88cc and CCA tubes. That's what I use for a more bursty, incisive sound from the amps, to the extent the input tube influences the output. The 5687/e182cc driver tube has more leverage over how the 845B sounds. The NOS Tung-Sol 5687 and the Mullard NOS e182cc wake up the big graphite plate B tube compared to milder versions, and the scarce and expensive (but long life) Bendix/Mu 6900 is the most aggressive and vivid driver I've found so far. Depending on how hungry your room is, that's either a great benefit or a step too far.

Overall, patience is advised at this stage. Especially when you are knowingly hearing gains and reversals. It was so much easier earlier in audio life to not notice, not care or not have downstream speakers to reveal such things...

Phil
>>I'm just saying (as Srajan did before) that just because a speaker doesn't have a crossover, doesn't mean it's better than others.<<

There's an error here that is a misstatement of what's actually been said by me and others about crossoverless speakers. At no point has it been written here that one speaker is better than another just because of being crossoverless. In fact, I've written explicitly that there are poorly-executed crossoverless speakers and well-executed crossover-based ones. Zu's breakthrough has been that it has demonstrated that a crossoverless speaker can be built to the frequency accuracy standards claimed for crossover-intensive/multi-driver speakers, while crossover-based speakers have not been made that shed, prevent or eschew the deleterious effects of passive dividing networks.

There was a time that in order to gain the clear advantages in unity and holistic projection of a crossoverless speaker, you had to accept fundamental and often distracting compromises in the essentials of fidelity. And some still chose to do that. Zu and others are meeting or beating the crossover adherents at their claimed "accuracy" game while delivering unity behaviors and resulting sonics not attainable from dividing networks feeding several disparate drivers.

Phil
>>...this is the second time the 4s have been described as lean-sounding, first by Roy Gregory in his Audio Beat web review, and now by you.<<

The Def4s are not "lean" sounding. They are just more objective than most of what passes for a listenable speaker in the price range, and much less artificial than the many crossover-based competitors with tilted up detail and treble gloss that isn't present in actual acoustic instruments.

If Druid V is your reference, Def4 is "lean." But it's Druid V that has the contributing error (though a euphonic one), not Def4. Now Def4's slight midrange recession is less present than in Def2, and particularly because of the extended beauty of the Radian 850, Def4 can make a difficult solid state amp listenable in a way that it would not be on Def2. Such an amp is generally lean itself. A relatively objective triode amp, like a Coincident 300B or Audion Golden Dream running KR 300B tubes will nicely maintain Def4's objectivity.

The larger problem with leanness is the rest of the audio chain. Almost every modern phono cartridge has a lean recession. All but a very few solid state amps have it. Nearly every Delta-Sigma DAC at any price is guilty. And then it's a sonic bias built into the majority of our current recordings. Between the modern propensity in hifi to sacrifice tone in exchange for unnatural detail, and relative slowness, unintegrated behaviors, and real-world colorations in the vast majority of speakers people hear and buy, it's easy to imagine why some people hear Def4 as "lean," but reality is context makes all the difference.

Phil
3' from front walls should be no problem. My Def4s are closer. The side walls proximity is more likely to alter your sound in ways both noticeable to you and that you might feel need to be managed. You also will probably have to alter your sub settings, as you will be close enough to the corners for horn/corner effects to be heard.

Key is, we all have to deal with the rooms we have unless we build custom rooms around a system. So there are going to be some differences changing placement to accommodate a large screen. It's pointless to obsess on the immediate differences that register to you in contrast to placement you just migrated from. Live with it and adapt where you can to make up the differences, and where you can't let the new reality sink in. Adding substantial screen real estate to a room & system tuned for hifi, comes with some compromises in most domestic settings.

Phil
I don't have extensive experience with the NAT amps but when I've heard them, they were energetic but totally dark and while relatively quite good they did not exhibit to me the same league of speed & transparency that distinguishes Audion. That said, I again caution that while the frequency response of various 845 tube types in a given circuit are not meaningfully different, the presentation of detail, harmonic presence and events vary noticeably by power tube choice, so if you like the NAT for specific reasons it is possible that any shortcomings can be addressed by different tubes. NAT sounded more like Melody than Audion in my listening. How one perceives bass imaging is hard to anticipate without knowing their room.

The Black Shadow transmits excellent bass character but it isn't the last word in bass slam and shove. The Audion 845 has a lighter, faster step, better for resolving texture, differences in instrument materials and playing techniques. If electronica or EDM is your measure for convincing bass, then other options with more push and less nuance might impress you more wrt bass. However, the fleetness and agility of Audion prevails up and down the frequency range and for that you get more illumination and beauty from Audion than NAT.

Your Hovland tube preamp will mate well with the Black Shadows. It's possible you'll prefer different tubes in it with the Audion than with your Radia, and even the choice of 845 glass may alter your preference for preamp tubes. For reasons I haven't yet determined, I find my Black Shadows much less compatible with a TVC than are my 300B PSET Golden Dream monoblocks. My S&B-based (pre Music First) TVC is sonically synergistic with the Golden Dreams but I've never found it equal to a good active tube preamp with Black Shadows. Maybe you'll have a different conclusion.

The Audion line stage matches well, of course. It shares the speed, agility, tone density and transparency of Audion tube power amps.

One thing: the Black Shadows have input level controls and the amps have input sensitivity of 0.7v for full power out. So you need to scrub off some gain. Since SET amps aren't completely silent like your SS Radia, generally the best way to run a preamp with Audion amps is to turn the input level control down quite low, where you have great range of utility in the rotation of the preamp volume control, rather than to run the amps wide open and have little useful rotation on the preamp volume. Play with the gain relationship until it sounds best. With my Melody P2688 preamp, my Black Shadow input level pots are set at 9 o'clock. With my Audion preamp they were at 12 o'clock high.

Phil
Spirit,

With small glass preamps, the question is, are you a vintage Telefunken or vintage Siemans listener?

Back in the day of early High End, when Absolute Sound was getting started, we used to resolve this question in the Audio Research SP3, SP3a, SP3a-1 by putting Telefunken (back then it wasn't "NOS" it was just Telefunken) glass in the phono section and Siemens in the high level, though you might reverse that depending on your phono cartridge. Now you're usually dealing just in line level pre amplification.

Of course there was room for the Mullard, RCA, Osram, Valvo and Mazda midpoints. The 50s Teles should be musically convincing and tone-rich in that pre.

You can adjust the Audion input & driver tubes in the same fashion, and use the leverage of the 845 to dial in the amps. You'll probably set the Black Shadows with base 845A tubes, which deliver an upper midrange/low top glare. If you hear that try to listen around it and if you report what you heard otherwise I can suggest some tube combos that bring it (or other 845 amps) in line with your preferences in presentation and tonal composition.

Phil
>>So can SETs, Audion or NAT in my case, return the presentation to a more tonal mids centred presentation without losing the real cognitive ease I have with the system as is with the Hovlands?<<

Yes. But you can't determine this for sure in a day or two. Essentially, you must listen for reasons to commit and then know you have to take the time to allow power supply break-in, tubes experimentation, and even possibly be prepared to adjust your cables loom or your source. With a Zu speaker, the power amp is the most influential next component and anything you select can disrupt prior choices you made elsewhere in the system, especially if such choices were made in the context of previous crossover-based speakers, solid state components, etc. If some basic element of what you hear in your SET auditions grabs you, then you have to make the jump if you want to get the most out of it. In other words, migrating from the Radia to an Audion SET amp will be a start, not a finish.

In Audion terms, there is great synergy between Black Shadow and its 845 tube, and Definitions (any vintage). But for some the same-power / less-drive Golden Dream 300B PSET amps can be the ticket. Just understand that for Black Shadow alone, the differences in perceived presentation between the 845A, 845A cryo, 845B, NOS RCA or United 845 and KR 845M, for example, can be quite large. If you want a destination amp with no further experimentation needed, then probably stick with what you have because any change in topology is going to set you on a course of discovery, and some disruption to your satisfaction with other aspects of your system. But if you do hear the Audion SET advantage enough to want to take that trip, then know you can bend the aural presentation via a variety of options downstream, or even when you spec a new pair to be built by Graeme's team.

I don't think there's any long term disadvantage to leaving push-pull solid state behind. I haven't changed my power amplification in either my Defs or Druids system since 2005, and it's not because anything was constraining me, other than not having heard anything better. But I bought both of my current monoblock pairs knowing they could be disruptive to some other choices and knowing that from that starting point, I would have to live with them for an extended period of tuning to get them to their best. I had no regrets whatsoever.

Phil
Spirit,

A few items from your SET experiment:

1/ These SET amps, and especially 845 SET, can be sensitive to mechanically-transmitted resonance and vibration. With Black Shadow monoblocks, one tends to place them close to the speakers and run relatively short speaker cables. With Def2's rear-firing sub-bass line array, the problem of mechanical resonance in the deep bass region was easily managed. I found with Def4 and the downfiring 12" sub, that I had to take extra measures to isolate my amps when placed adjacent to my speakers, and this is on a wood composite floor bonded to concrete in a 1-story slab foundation house. If you have suspended flooring, it's worse.

I use Herbie's Audio Lab Iso-Cup/SuperSonic Hardball under my Black Shadows, and Herbie's Medicine Balls under my Audion Golden Dream PSET amps. The difference in bass articulation and bringing bass back into balance is quite large. Without resonance management, the vibration transmitted into the amp induces what sounds exactly like steeply-rising bass harmonic distortion -- euphonically fat until it isn't. You might experiment with this to get the cleanest possible bottom end.

2/ 16/44 digital material definitely has a different top end presentation than analog, and both are highly variable by material as well as the source the system sees. By the latter, I mean that for vinyl analog, phono cartridges and cartridge/tonearm/tt combinations are virtually fixed-paramentric tone and phase controls. There's no objective standard despite the 20Hz-20kHz flat frequency trace that came with your cantilevered transducer. Same is true for DACs. There are some characteristic traits to 16/44, 24/48, 24/96, 24/176 and 24/192 sound, but they all have the potential to sound wrong in some way, as well as right. And Non-OS DACs for 16/44 material sound distinctly different than delta-sigma types. And then 1-bit DSD has its characteristics.

Given that the power tube (particularly) choice in an 845 amp discernibly alters presentation if not response, if you're really fanatic about it, you can listen to analog and digital on different output tubes. It isn't unusual for well-appointed vinyl analog to sound harmonically complete, compared to 16/44 digital. If you have a DAC with multiple filters to select, experiment with those alternatives. You may find that you prefer a different digital filter type for SET than for SS or push-pull tubes. The other thing you might consider is a good Non-OS DAC specifically for 16/44 material.

Phil
Chas & GB,

The Audion Elite, as I understand it, was developed to keep the cost of the Black Shadow circuit in check. So it costs less than than a pair of Black Shadows despite having the cost of a third chassis. The Elite doesn't have "an extra power supply," it has a common power supply to both channels and that is isolated in the third chassis. Only audio circuitry is in each L/R chassis.

When I compared an Elite to my Black Shadows, it was tonally almost identical, but it was less punchy and tidal in its dynamics, and the soundstage was somewhat smaller. These were relatively small differences, so for anyone who needs to save the $1500 price diffence, the Elite 3 box 845 will be impressive and outperform almost all other 845 amps I can think of. But the 3-chassis arrangement is a difficult complication for placement.

Each of the three chassis is smaller than the chassis of the Black Shadow. I didn't get inside Elite and never got a clear answer from Audion about whether the power supply is just smaller than that in Black Shadows but still using two power transformers, or just one common transformer. I think it's the latter. Less than 2 lbs. separates the total packages by weight, though. Audion's own catalog describes the Elite as the "budget version" of the Black Shadow, though when it debuted, Black Shadow was discontinued and Elite was positioned as its successor. Popular demand for the real thing brought it back. Regardless, Elite sounded a step behind in direct comparison to its big monoblock brother.

Phil
John,

1) Can you offer an opinion comparing the Def 4 to the 10c?

Different machines. My main reservation to the Sanders and all prior mixed-driver speakers is the dynamic mismatch between (in this case) the 10" transmission line bass element and the ES panels. It's distracting to me and no one has ever really closed the gap. But if you don't notice it, the Sanders is quite good.

The Zu, however, is 7db more efficient, and that gives them a sense of bursty dynamic life the Sanders doesn't really match. The Sanders has an advantage in sheer articulation, but most hifi is over-articulate compared to how real instruments sound at listening distances. I've been a long-term ESL listener and all I can tell you is that after landing on Definitions, I have no reason to go back. You might prefer to continue.

2) Has Sean settled on caps? Apologies if this is already answered; haven't gotten all the way through the thread.

Sean will never "settle" on caps. It's a continuous improvement investigation. For now, Clarity is standard.

3) Which caps do you think sound best in the Def 4 context?

There's no one answer. Like speed, how much do you want to pay? Clarity MR are quite good, after a long burn-in. If price is no object, Duelund should have your attention.

4) Any additional considerations you believe I should investigate beyond your original list?

Better to ask questions.

Phil
>Phil, is there a way to identify which version of the super tweeter is in my Def3's?

It tends to get bright to me especially at louder volumes.

Do you think a cap upgrade would help with this? Thanks, scott<<

Yes; call Gerritt or Sean at Zu. Seriously. Especially on the very low production models.

What is your amp? If the Def3 supertweeter sounds bright to you, a cap upgrade will definitely help, but if you talk with Sean and tell him what you're experiencing, a small value change to the cap may be in order as well.

Phil
Two more things:

1/ Druid IV is generally more forgiving sonically than Omen Def, but this can depend on the driving amplifier.

2/ I ignored Essence in my notes because I'd easily choose wither Omen Def or Druid IV over it, 

Phil
"I guess my question is - for $300 more (than the Omen Def) is the Druid Mk. IV a no-brainer?"

Jim,

Druid Mk 4 and Omen Def are, within the scope of Zu, very different speakers. Either one could be preferred for specific reasons over the other. If you were angling for Druid V over Omen Def, my answer would be conclusively in favor of Druid.

Omen Def benefits from the dual-FRD implementation of a "Definition" Zu speaker, so it is a higher-resolving loudspeaker than is Druid IV. But as an iteration of the Omen construction, it also has more cabinet talk than Druid IV. So it's an "on the one hand...." situation.

Omen Def is also the lower impedance speaker and its power transfer characteristics will make it seem a bit more efficient than Druid IV, along with having an impedance into which most amplifiers will deliver somewhat more of their available power.

Druid IV does have a warmth to its tonal balance that can make the very top end seems soft, compared to Omen Def. However, Druid IV demolishes Omen Def in tone density, spatial focus and true instrument-character midrange tone.

In simple terms, Omen Def is the better big, bouncy, party speaker. It's dual-FRD configuration will lay out a bigger soundstage filling a bigger room. And its bass extension will be deeper. Omen Def will play big music with more appropriate scale. Druid IV is the better serious listening "pay-full-attention-to-the-music" speaker, and it is in league with the best at reproducing convincing stringed-instrument tone, and it doesn't matter whether the strings are on electric guitar, viola, piano, Spanish guitar, dulcimer, mandolin, banjo or washtub bass. Druid IV will be spatially more precise and its bass character more nuanced and articulate.

So, tell me about how you listen, where and what makes attempts at fidelity convincing to you, and I can say specifically whether $300 is better spent on Druid IV or on more music. Otherwise, knowing these speakers, now know thyself.

Phil
Charles,

Thank you. Software startups severely divert me from my personal interests for extended periods from time to time. I've been following but scant on contributions, watching others answer for me. Trying to carry my end of it again.

Phil
Dentdog,

What are the dimensions of your listening space, and how far from the speakers is your listening position?

Phil
Dentdog,

Your room isn't very different dimensionally from the room my Definitions system is used in. That room's dimensions are 21' x 14' x 8-1/2', and it's in an open plan house, so there are substantial non-bounded openings on two sides. I listen 10-1/2' from the speakers.

It's difficult to know for certain what is aggressive to you vs. me. However, I've never hit any practical limit with my 24w Audion Black Shadow monoblocks (845 power tube). Same with my 24w Audion Golden Dream 300B PSET amps. If they were double that output, it would only yield a 3db difference. My room clips before the amp is the major problem.

You will always hear the limits of an expensive amp in some way. It might be dynamics. It might be sudden onset of harsh, odd harmonics clipping. It might be in terms of the definition and tone you sacrificed in exchange for more power. You also should consider whether you in the past have used volume to try to find more detail in your system. Many people do this without realizing and then find that they listen at lower SPLs after one or more upgrades. Hard to say. But if you truly fear that Black Shadows won't be enough, then you probably will need to make the jump to push-pull in the 80-120w range. An Audio Research REF75, for instance, using the KT150 tube, Quad Two-Eighty monoblocks, many other choices and all different presentation than Audion.

Line Magnetic amps are well built and sonically robust. They don't have the same speed and transparency as Audion's SET and P-P circuits but certainly very credible if you like their more old-school tube sound. That line is not my sonic recommendation, but there's nothing wrong with considering them from a quality of execution standpoint.

Keep in mind that Definitions have a powered sub-bass section where the sub amp's input is derived from the main amp output signal. One effect is this relieves the main power amp from having to drive large amplitude deep bass. The speaker's parametric settings will determine how work is divided between amps there, but nominally your tube amp will be doing very little muscling below about 35-40 Hz.

Phil
I have had the Melody M845 in my own systems for extended audition, with the specific mission to get it as close to the Audion Black Shadow as possible, through tube rolling.

These amps are made to a very high standard of build quality. The stock-tubed M845 is not nearly as fast, dynamic and transparent as Audion, but they are half the price, hence their attraction. The stock tubes afflict the amp with an old school, rolled-off, lazy sound, leaving the sonic gulf between M845 and Black Shadows enormous and out of scale to the price difference. Fortunately, you can close the gap considerably by ditching the stock tubes in favor of vastly-better replacements.

Working back from the power tube, the ubiquitous and prosaic Shuguang 845A stock tube has good dynamic shove, but it has a dry, chalky character with a stunted top end. If you needed to stay cheap, getting cryogenically-treated 845A improves things but you can do much better. The cryogenically-treated newest Psvane 845 (it's a "B-type" diskless-top carbon plate) extends the treble, opens up the sound and gives bass more discipline and depth. For an even more transients speed and transparency in the vein of Audion, us the newest 100w dissipation Shuguang 845C metal plate. The older 70w dissipation 845C works. Ideally power tube bias as stock is a little hot for that tube, so yu will get some faint cherrying of the plate. It's stable though and won't go runaway, and in my experience the tube life isn't severely affected. But if you want the 845C sound without either a re-bias nor nagging concern about dissipation, the newer 100w dissipation 845C is a drop-in.

Next, the amp uses a 2a3 triode as the driver. The stock tube throttles the amp's sonic potential. By far the best way to put some added punch and clarity in the mix once the 845 is sorted, is to toss the stock 2a3, replacing it with a KR 2a3.

Last, the input tube is a 6sn7. The stock $5 tube is notoriously bad sounding. You find these in a wide range of preamps and amp inputs today because they are cheap and reliable. Put it in your backup tubes drawer and replace with either a NOS RCA red base 5692. Alternatives in new production are the Shuguang Treasure CV-181 (which isn' really a cv181 at all but that's another story) or the Full Music/Northern Electric/ Sophia 6sn7. With the Psvane cryo 845, the RCA is a great match. With the somewhat colder sounding 845C, the Treasure CV181 contributes a little offsetting soul. Use a clean, objective power cord like a Zu Event II and you're golden.

The Black Shadows are still well worth their premium but tubed properly, the M845 is convincing at its price and you can settle in for extended satisfaction for a more approachable fee.

Phil
Zu has to pace its new model rollouts, given the capital requirements of a self-financed company. What you're seeing in the reported content changes to Druid 6, the rumors about Experience and Presence is convergence of the past Zu sound families into a more coherent house sound, a general push to wring noise out of the cabinets, and a more rationalized speaker line with a logical price/features ladder.

For most of Zu's history to-date, there was a distinct voicing and presentation difference between the dual FRD speakers and the various single FRD models. This two-branches-of-a-Zu-sound was starkly apparent as soon as the original Definition joined Druid in the line. Druid was immediate, focused, bursty but vintage-warm. It sounded like you had an old-school triode amp on it regardless of what you connected to it. Definition by contrast had from its first version a cooler, faster, more diffused and impressively big stage at some expense to the solo performer focus and vocal magic of Druid.

Definition 2 moved some Druid traits into Definition, largely due to its overbuilt ply cabinet, compared to the livelier MDF-based Def1.5. Druid IV/09 revision cleaned up Druid bass considerably and began to address what many people heard as a rolled-off top end.

Definition IV and Druid V were the inflection points in the conversion of sonic traits. Druid V got a much quieter cabinet, the progressively more neutral Zu FRD, the Radian compression tweeter and a more perfect expression of he Griewe acoustic impedance cabinet. The result was the first Druid that had enough soundstage width for full orchestra and movie soundtracks, the snap and sparkle of Definition and sharply-improved dynamic and texture unity from its deepest bass through the midrange and treble.

Def4 kept and improved all its prior advantages in tonal neutrality, scale, snap and bass mining, but it gained focus and near-er field listening potential, got nearly the full dose of Druid's loved tone density and also gained improved unity between its deep bass output and the rest of the speaker.

Notwithstanding how fast the line below Druid catches up, Druid 6 will be a more neutral, blacker, snappier refinement over Druid 5. Presence will, based on the prior model, give you the option of Druid sonics with active bass extension, in a more room-friendly form factor than the 2000s version. Definition will continue its role as the constantly progressing true high-end speaker for under $20K, and Experience, when we get it, will be something on the order of the $30,000 speaker (pair) that shames what the rest of the industry offers at twice the price.

A voice-unified Zu line will end or at least curtail the selling-friction buyer debates about whether to get, for example, Omen Def with upgrades or Druid. Druid + subs or Defs. Because you won't have to choose whether you want Druid's compromises or Defs'. You will be able to pick your price, confident that you aren't having to sacrifice orchestral scale to get singer-with-guitar intimacy, or vice-versa.

A lot of this is being accomplished through materials research, trial-and-error and collaboration. The speaker architectures are not radically changing but materials combinations, improvements in manufacturing at Zu, along with their advancements in finishings constantly put new value in the line. What's coming has already been shown by what's been delivered since roughly 2009.

Phil
Any new Presence would be a re-appearance of the original in a different form factor. If Sean makes it, it won't replace anything in the current line. It would sit between Druid and Definition. Presence as defined by the original, is a single FRD speaker with supertweeter + an active bass module ala Definition. So, more expensive than Druid; less than Definition.

Soul and Soul Supreme sit below Druid in the line.

Phil
I expect to have Druid 6 comments posted later this month. There's a back story regarding why I chose to put RIAA in the digital domain for one tonearm in both of my systems, which I suppose I'll include since people seem interested. Both systems have two tonearms on the Luxman PD444 turntables, so each one also has an arm/cartridge connected to conventional analog RIAA/phono pre duties.

But, the A>D>A arrangement on the Ortofon SPU in the Druid 6 system, and on the Allnic Puritas in the Definition 4 system flummoxes everyone because it still sounds analog to them. Not that I don't take plenty of flak from people before they hear it.

Phil
Getting the Druid 6 FRD into the Def form factor will require a new cabinet interior design, and even the mounting holes for the drivers have to be somewhat different spacing than in Def4. For doing all that it only makes sense to also apply the materials and construction methods from the Druid 6 cabinet, to next Definition. Then there are the decisions regarding the sub and electronics. Patience is your friend, and there's a good chance you'll need less of it than you might fear.

Phil