Seriously considering tube preamp…opinions?


Tube virgin, here. I am building a system and I'm trying to contain the preamp/amp cost to $3k or so. (I could go up a little.) 

I'm inclined not to dive into tubes all the way through, but get a solid state on the output end. (Open to suggestions; inclined toward PS Audio, Parasound.) I'm reading around about tube preamps and have talked with my local dealer, who sells Black Ice/Jolida and Prima Luna (PL). He used to carry Rogue but said they kept coming back for repairs. That's why he carries PL.

I'm asking these questions after having established (via reviews, comments) that Schiit gear is quite the value. Lately, I've been reading about Decware and other small tube makers. I'm very curious about buying direct, if possible, and a company that stands behind their products is crucial.

So, your opinions about tube integrated or *especially* tube preamps —

1. Who do you like? Consider I want to do pre/amp for a total of $3k if possible.

2. Do you think PL is worth all that money just for a preamp? I get the feeling they're high quality but a bit over-hyped. (No disrespect to the highly passionate Kevin Deal, but he's all over my search results.) And what would you think about $2k/$1k preamp-to-amp spending ratio?

3. Any sense of what happened to Jolida since the name change to "Black Ice"? I see there's a sordid story there but did the re-branding clear up the mess? Any experiences with the Black Ice company?

4. I know there are many Schiit fans out there; so my question would be -- did anyone consider Schiit for tube preamp and go another way? Or move beyond Schiit for any particular reason? It's hard not to just capitulate and do a Freya+ or Saga+ but why wouldn't one just go with Schiit?




128x128hilde45
Regarding the PrimaLuna EVO 400, I don’t know about that specific model but Stereophile’s measurements of several other PrimaLuna amps reveal them to have very high output impedances, even for tube amps. That stands a good chance of resulting in tonal imbalances when paired with many small two-way speakers. As well as with some larger speakers, depending on how their impedance varies as a function of frequency, and especially if the speaker was designed with the expectation that it would be driven with solid state amplification.

Regarding VTL, over the years a number of members have reported in threads here that they had customer service experiences with VTL that were, shall we say, less than ideal.

To add to Tvad’s comments about VAC amplifiers, with which as a former VAC owner I entirely agree, a nice thing about them is that they usually include a 2 ohm (or "1-2 ohm") output tap, in addition to the usual 4 and 8 ohm taps. The lower the impedance designation of a given output tap the lower the corresponding output impedance will be, and that additional tap adds significantly to the amp’s versatility with respect to speaker matching. The VAC models that were mentioned above include that third tap.

Regarding ...

At what *starting* level of db sensitivity does the choice of quality all-tube amplification open up? 88db? 92 db? more? (I suppose I’m not thinking of the tiny-watt tube systems, but things that are up to 35-40 wpc)

... Answers to that question will vary considerably among different listeners. And IMO a major reason for the variability is that it depends on the dynamic range of the kinds of recordings that are listened to (i.e., the **difference** in volume between the loudest notes and the softest notes). As I think I mentioned earlier in one of your threads there are some classical symphonic recordings in my collection that have been engineered with minimal or no dynamic compression which can reach brief dynamic peaks of 100 to 105 db at my 12 foot listening distance, while being listened to at average levels in the 70s, and with the softest notes being in the low 50s. And lest that amazing 50+ db dynamic range be questioned I’ll add that I have verified those dynamic ranges on a few such recordings by examining their waveforms on a computer, using a professional audio editing program.

Tvad’s suggestion of 90 db or more as the answer to your question is certainly reasonable. Beyond that the only things I can suggest are to try plugging various numbers into the SPL calculator I linked to earlier, and preferably to obtain an SPL meter which provides fast response time and "c-weighting." I use an older Radio Shack model 33-2055 digital SPL meter, which may be findable at eBay.

Finally, as a Daedalus owner I certainly agree with Tvad’s comments regarding them. However all of their models are floorstanding, and their prices may be discouraging. There is a used Daedalus Athena for sale here presently for $6K; with the possible exception of some particularly old models I doubt that other models are likely to appear for sale for much less than that.

Best regards,
-- Al
At the beginning of your quest, based on 3 threads many here have contributed on, you have increase your system budget from $5-6K to $10-11K. The room size the system  will be placed in has increased from 150sq.ft. to 450sq. ft.  This is not an unusual outcome for someone entering this hobby, the extra funds and room size provide greater flexibility for, and enjoyment from the end result. Al the better for you.

I would reconsider the speaker budget to around $3000. This would allow for a stand mount speaker that could provide deeper bass response at greater sensitivity.

Your budget of $5-$6K for amplification opens up many possibilities. At that level the use of separates become more feasible. However I am not saying that the end result would be better over the right integrated. You started out your quest not sure you wanted to enter the 'tube' world to the extent of using tubes for the output stage. There are many who also think this way. I myself have saved that as the last consideration. There is no right or wrong between SS and tube based amplification.

This leaves you with $2K-$3K for source components. Since you already have a transport you would will be looking for a DAC. You also mentioned wanting a streamer.

I suggest you visit the several dealers in your area, be on the lookout for any used equipment that fits into your goal I have saved several dollars going this route.

I have my grand sons home with me (3-4 years) and they just got up. Have to sign off. Will get back

Take your time and enjoy your quest. 


@tvad Thanks. I did consider that perhaps since my Salk order is standard veneer and not delivered yet, I might just change my order with Jim and go with a more sensitive speaker. Not sure if he’d allow that but IF the speaker I ordered was of higher quality and price, I’d still come out the same in overall costs and Jim would sell a more expensive product. (I don’t want to make assumptions about what he considers reasonable, so I’m ready to be rebuffed if he balks at such a proposal.)

The key issue is that the other models I might now consider that are more sensitive than the 84 db speakers I order are: 87db, 88db, or 90db. The 90db speakers are more than double the Wow1’s ($3800 vs. $1500). QUESTION: a jump of 3 or 4 db in sensitivity doesn't really buy me enough, does it? It should be 6db? 

@almarg Thanks for reminding me of the dynamic jumps. That’s key part of music realism in the genres I enjoy. Good to have 90db as a starting point. That may rule out some makes of speaker if I try to broaden out my amp choices. Daedalus is nice, perhaps a bit much for me right now. I’ll keep an eye open.

@mesch Part of it was increase, part was just thinking out the wider parameters. "I wandered into a bar, looking for love," kind of captures my state of mind at the start.
I will reconsider the speaker budget. Part of that might come from a higher sensitivity speaker choice. The output stage (tubes or not) is still open. I have heard both sides. But I also am aware that matching tubes/ss is a dangerous game, and I’m a bit shy on this front. That leads back either to integrated tube/ss, all tubes, or all ss.
I will check for used and visit dealers.
Thanks for posting and enjoy your family time!
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@tvad 90db. Ok. (I guess 88db isn't better enough.)

Bookshelves: I began with bookshelves because I wanted new desktop monitors. Then, I opened up to the idea of a larger room/space. In the meantime I bought a sub. As I got deeper in, I realized that I really wanted a listening space. So, I guess bookshelves are a remnant of the earlier parameters — and I think they do offer flexibility for future placement. But if I was to be pushed, well, I guess I'm now at the point where I'd entertain floorstanders. Here come the Maggies! (Just kidding. I think.)
@hilde45  The thing you have going for you with the Salk speakers is they have a moderate 8 ohm impedance with no nasty phase angles or dips. This makes the job of the amplifier easier. Jim is pretty conservative about his ratings- I suspect what passes for 83 dB or so for him is 86 or 87dB with some other brands- it depends where on the curve of the speaker you measure its sensitivity!

If I can make a suggestion: When working with **any** amplifier (tube, solid state, class D), its distortion will be lower if it is not asked to work hard! To this end, your amplifier investment dollar will be better served by a loudspeaker that is higher impedance (8 ohms as opposed to 4, and 16 as opposed to 8) because the amplifier will make less distortion. This is both easy to hear (as the distortion is higher ordered harmonics and addition IMD) and easy to see in the specs. When you can hear it and measure it, its real :)  In the case of tube amplifiers with output transformers, the higher impedance will allow the output transformer to operate more efficiently. When the OPT (OutPut Transformer) heats up, its converting amplifier power into heat :(  When driving lower impedances, not only does the OPT operate less efficiently, it can also lose bandwidth. On the bottom end this can be up to an octave of bandwidth loss between 4 ohms and 8!


On top of this loudspeaker efficiency is also important, particularly in the case of tubes, as tube amplifier power is more expensive (the industry went solid state not due to performance but cost reasons decades ago). This also helps the amp to make less distortion since it doesn't have to make as much power. A 3dB change in efficiency doesn't sound like much to the ear, but that is a difference of twice the power in the amp! So when you go from 83dB to 89dB, to make the same sound pressure the amp need only be 1/4 the power. The $$$$ implications should be obvious.


The less distortion, the more the presentation will sound like real music.


One other thing: lower efficiency loudspeakers are inherently less dynamic. This is due to heating of the voice coil- which in turn reduces its sensitivity. The more power you give it, the worse this becomes. There tends to be less thermal compression in higher efficiency loudspeakers.
I'm in a similar situation (looking for a tube pre / SS amp combo.) and I was wondering if there are tube pre's that are more suited to SS amp matching in terms of impedance matching.  Do I just go by the 1/10 rule (output impedance for the pre)?  This would narrow my search down considerably if I could find a tube pre that is SS amp friendly.  
Do I just go by the 1/10 rule (output impedance for the pre)?

No.

To assure impedance compatibility the 10x rule of thumb guideline should be applied at the audible frequency for which the output impedance of the component providing the signal is highest. In most cases impedances are specified at a mid-range frequency such as 1 kHz. It is very common for tube preamps to have output impedances at deep bass frequencies that are much higher than that specified value, often 2K or 3K or even 4K ohms. That rise at low frequencies results from the output coupling capacitor that is used in the majority of tube preamps, and also in a few solid state preamps. The impedance of a capacitor increases as frequency decreases.

So ideally the 10x rule of thumb guideline should usually be applied based on the output impedance at 20 Hz, in the case of a tube-based preamp. If as is often the case the component’s output impedance at 20 Hz is not known, and is not indicated in published measurements (such as those Stereophile often provides), and if the use of an output coupling capacitor in that component cannot be ruled out based on available information, to be safe a considerably higher ratio than 10x should be used, something like 50x or 75x IMO.

This applies, btw, to tube-based source components as well as to tube-based preamps.

Also, to clarify a common misconception I should add that failing to meet that guideline does not necessarily mean that there will be an impedance compatibility problem. It depends on how much **variation** there is in the output impedance over the frequency range. But meeting that guideline (at all audible frequencies) assures that there won’t be an impedance compatibility problem.

I should note also that a significant number of tube-based preamps use coupling transformers at their outputs, and therefore avoid that low frequency impedance rise. Although depending on the specific implementation transformer-coupled outputs might have downsides of their own. Atma-Sphere MP-1 and MP-3 preamps, btw, cleverly avoid the use of both capacitors and transformers at their outputs. (I’m not sure about the UV-1). As far as I am aware they are unique in that respect, among tube-based preamps.

Best regards,
-- Al

@atmasphere Thank you for your comment about speakers. It definitely helps.

@almarg You are one tireless explainer! I keep learning.

@russellrcncom I’ll be curious what path forward you take. I began with the idea of a tube/ss hybrid -- where some manufacturer works that out for me. I’ve moved toward the idea of separates, ideally matched by the same mfr or at least of the same type (tube or ss). I have moved away from mixing and matching myself because of (a) the experiences presented here that it could be somewhat tricky to do in a way that has a pleasant outcome and (b) because I won’t have many opportunities to try out combinations, first. The last thing that I want is to just grope in the dark for synergy -- to mix and match and discover, soon after purchase, that I have to try to sell one of the pieces I bought because it doesn’t work. And remember, there is also (c) the speakers to match up with all of this, too. 
and I was wondering if there are tube pre's that are more suited to SS amp matching in terms of impedance matching. Do I just go by the 1/10 rule (output impedance for the pre)?
Al's comment is correct- look at the 20Hz output impedance if you can find that spec. **That** impedance is the one that you want to be 1/10th that of the input impedance of the amp. In the case of our MP-1 and MP-3, the output impedance is the same as the frequency response curve (which is to say that their output impedance are the same at 20Hz as 1000Hz) but this is as Al pointed out, owing to a balanced direct coupled output (which to my knowledge is the only other way to support the balanced line standard outside of using a line transformer at the output of the preamp).

@russellrcncom 228 posts 02-26-2020 10:27
I’m in a similar situation (looking for a tube pre / SS amp combo.) and I was wondering if there are tube pre’s that are more suited to SS amp matching in terms of impedance matching. Do I just go by the 1/10 rule (output impedance for the pre)? This would narrow my search down considerably if I could find a tube pre that is SS amp friendly.

You can also future-proof yourself by finding a multi-purpose tube preamp that not only mates up well with your solid state amp, and a future tube amp down the road later on.

It happens :)


I've had PrimaLuna Prologue and Dialougue,  Rogue Audio Magnum 99, and BAT VK-30. I liked them all. If I am to pick the best sound, probably Rogue, but the only problem was it was a bit microphonic. Currently I use Dialougue, and I am quite happy with it.
Another vote for the Backert Labs Rhumba 1.3. I just replaced my Mark Levinson 380s with one.  Was a huge improvement.  Much more dynamic and open.  
Thanks Ihcho and 93cobra

I'm looking now at that Rhumba 1.3.
It is kind of a bummer when they tell you how much better the Extreme is! Just when I'm thinking, "This is the right price point for me" they go ahead and tell you all the ways things could be better. Aaarrrggghhhh. https://backertlabs.com/new/
I warmly invite you to consider tracking down and auditioning a pair of Quad ESL speakers. 63s, 988s, 2805/2905, etc. Any of these might require a rebuild (cost about $2000 with shipping) but there is a reason why these are universally well regarded.

There are many solid state amps on the used market that would work well with these. Quad 909 for instance. This approach would result in a speaker/ power amp combo for around $4000. A budget of $2000 - 2500 would provide for a brand new 6SN7 based tube preamp that would blow your mind. Figure ~1200/1500 for a tube buffered DAC (Tubador, Orchid...) and stream from your laptop or a used cd/DVD player picked up used for $10 - 50 and you’re golden.  This would result in a system close to state of the art.
Someone is always going to tell you how much better something that costs twice as much is. You've kinda bounced all over the place and had a lot of advice so here's  my 2 cents concentrate on the speakers first and foremost those along with your room is about 75% of what you'll hear. 
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I’ll let you know how the Extreme sound compared to the regular 1.3.
I will have one to audition in my system as soon as I get time. 
I did a lot of speaker listening and narrowed it down, but I didn't comprehend the implications of sensitivity because I had yet to experience how much I liked tubes. That's the reason this has gotten so complicated. 
Just to add -- thanks for continuing to question my initial speaker choices and offering new ideas. Since nothing has been purchased yet, there are still listening opportunities. At least 1 person has suggested upping my speaker budget, knowing that it could come out of the amplifier portion (since that could be reduced concomitantly).
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Linear Tube Audio Microzotl Preamp is an incredible piece.  I own it an and everything that is said in the below review is spot on.  Take a look at Terry Londons review (teejay).

https://hometheaterreview.com/linear-tube-audio-microzotl-preamplifier/


@jaudio1 Thanks, will take a look.
@tvad Zu is a good option. I'll take a look and maybe they'll come my way. Good price points. I was curious about Omega, also, but I wrote them and there is no home trial. You buy it, it's yours. Done. https://omegaloudspeakers.com/collections/monitor-speakers/products/super-alnico-monitor?variant=32172390412

Any thoughts about Ascend or Fritz?
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Thanks, @tvad That is quite an attractive option. I don't think a flight to Ogden is in my plans yet, but then again, I think Tekton is within driving. I could compare those two companies' stuff...and catch the Mormon Tabernacle Choir.

warmly invite you to consider tracking down and auditioning a pair of Quad ESL speakers. 63s, 988s, 2805/2905, etc. Any of these might require a rebuild (cost about $2000 with shipping) but there is a reason why these are universally well regarded.

If I may suggest, no offense, this is where the correct amplification can make or break it for someone - and so can the room you place them in. While I’m a fan of Electrostatics, a buddy of mine stepped up and bought his beloved brand new Quad 2905s to celebrate his retirement and a milestone birthday. Paid good money for them too. Was super excited for him. It all turned out kind of odd for him. The sound stage was odd, nothing really clicked. >>He put them up for resale within the same year as i recall<<. Heard them a few times with some really nice top-shelf preamps, different amps, you name it - they just sounded boring to me and others. Nothing special. What happened?

I bet the right amp would have made them sing BUT what I really think happened is they were placed in the wrong size room and position. He was stuck. Got resold. Someone got a great deal. Room was too small, short, odd ceilings. Some speakers just don’t sound right until you put them in a <right-sized> room that makes them shine.

Don’t forget the room! The room is the speaker too.
@decooney Great point. My two spaces are not all the flexible for placement. The nice thing about bookshelves -- and the reason I went with Salk WOW1's for a trial, is the flexibility which comes from small size and front-ports. That's what's probably dogging me on the low sensitivity front. Some of the speakers here may just be too large. Hard to do in-home trials of lots of stuff. pretty soon, it's gonna be a year and a lot of shipping.
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@tvad I sure will. I'm already a fair way down the road to a short list of very good amps suggested by folks here, I've auditioned things people have mentioned, bought literature to read, and after some painful lessons about the speakers I first fell in love with, I am even revisiting my initial commitments to speakers. If by "will I drink" you mean, invest in learning, I think the answer is "glug, glug, glug." 

But you probably mean "home trials, shipping, travel to audition, buying, reselling" and more. If that's the case well, "sip, sip, sip."
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As it relates to Rogue.....I own the RP-1. I reside in Atlanta and one of the biggest dealers lives here - never had an issue with Rogue - and any questions are quickly answered by Rogue owners - such as fixing my Ground-Loop Noise issue.

The equipment is solid and the RP-1, though only incorporating two 12AU7/ECC82,
and mated to my Vintage NAD-2200 (into 4ohm DYS full-range speakers) created lovely mid-range tones and even spatial (front to back) depth. This summer the NAD-2200 moves to a different room and the Rogue RP-1 will be mated to a new tube amp - I am still researching.
This all said, I may trade up to the RP-5 (the RP-7 does not fit into what I want/need). Major magazines have reviewed these Rogue units...give them a read. As far as your local dealer telling you about Rogue coming back for repairs....never heard this anywhere in the industry, or better yet, contact the staff at Rogue through email and tell them your concern. Good luck with your research and final purchase. 

Kind regards,Lance A. LewinAtlanta
All brands have issues here or there. Sometimes brand new parts can go bad and humans build them, gets dropped hard in shipping, whatever... things happen. Many get lucky and have no issues for 20+ years too. It’s the dealer and manufacturer support and response is what counts.

As @tvad said earlier, I agree it’s not easy to build a great system, and not always on the first try.

@hilde45,
Going from 0-100mph is not easy or common. Most do start with one component and branch out from there. Ya know, friends and I have built some really great little systems with really good class-a type Monitors in smaller and larger rooms and it sounded fantastic. Don’t discount the smaller speakers too. For many years I used smaller Totem Acoustic Signatures as a reference speaker to compare to when building my own speakers. With the right tube preamp/amp and distance from the wall and not a lot of furniture around, you’d be quite surprised at the results. 20+ years ago we set up a RM-9 tube amp, Audible Illusions Modulus III preamp, + very small Totem Model 1 Signatures with some really good interconnects. AES awarded him a 4th place award and whitepaper write-up from across the US for that little system.  The reviewers were shocked how good it sounded and me too. I heard that same system in at least five different rooms with at least 20 different pairs of interconnects too. The final room and setup made all the difference. The speakers were tiny and mighty. It can be done. Maybe go from 0-60 for now, it is an option if you do decide to upgrade speakers later too. Food for thought.
@tvad Thanks. I joined an audio club this morning and visits to folks houses in Colorado will be possible now. I will eat shipping as part of the process. Going to bake that into the spreadsheet. I contacted Tekton — no facility in Utah to tour. Just direct. Hoping to hear from Zu. I'll be at RMAF for sure. I'm realizing that this process may take a while. That's cool. I find it interesting.

@lewin Thanks for the info about Rogue. I definitely have options to try them in Denver. I suspect my local dealer said that in part because he now carries Prima Luna, but I'm not sure. He could just have anecdotal evidence that happened to align with not selling Rogue any more.

@decooney Yes, dealer/mfr support is so important and will make the difference. Appreciate hearing the system-history, too. Small speakers are not out of the question, for sure. The issue is driving them. Good point about 0-60, for sure. Maybe this is possible with the harder-to-drive speakers, but if that can be fixed before setting out on the tube journey, it is sounding like I've had sufficient warnings (about over-spending on tubes to power 84db speakers) and should correct that.
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@tvad If I might wax philosophical for a moment about what’s happened for me, here: this has been a great lesson in "slow technology," a drawing back from that impulse to go 0-100 mph right away. Part of that is impelled, I suspect, by how we buy things now — instantly. Such habits clearly shape, also, how many automatically seek to learn and communicate, too. A favorite thinker who’s been tracking this way of living for 30+ years, Albert Borgmann, calls it the "device paradigm." (He’s quite a famous figure; I recommend his books, and here a good one is: https://www.amazon.com/Technology-Character-Contemporary-Life-Philosophical/dp/0226066290)

But the impulse to speed and automaticity, lack of patience, isn’t necessarily how one must live (as you all know). Conversation and reflection slows me down and helps me realize that doing things quickly is often at odds with doing things well. This general point was familiar to me already (I’ve written on education and the rise of the smart phone), but because audio involves so many complex devices which "do it all," I didn’t grasp how firmly audio, too, is within this sphere.
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Tubes add serious harmonics to terrible recordings to make them sound better.   They also add harmonics to good recordings to make them sound worse.
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When i listened to tubes on good recordings, I liked the way they sounded. That was compared to solid state A/B and D class. I have not however tried the Pass Labs Class A. I'd like to do that.
hilde45 OP211 posts02-28-2020 8:24pm

When i listened to tubes on good recordings, I liked the way they sounded. That was compared to solid state A/B and D class. I have not however tried the Pass Labs Class A. I’d like to do that.

--------

^^-above-^^ IMO, I’m not so sure I buy 100% in to the comments above regarding good recordings sounding worse with tube amps, added harmonics, etc. And particularly not with higher quality pentode / ultralinear tube amps designed with zero feedback. Just like solid state, not all amps are created equal.

hilde45,
When you do audition Pass, ask the dealer if you can listen to the INT-60 with 3-4 different types of speakers. Nelson’s amps can truly sound quite different from one speaker to the next. And, some of the higher-efficiency  speakers are not as "musical" sounding to me when paired with some of his higher current amplifiers. A good Pass dealer will know what to show you and what pair them up with so you can hear differences.




Danvignau 2-28-2020
Tubes add serious harmonics to terrible recordings to make them sound better. They also add harmonics to good recordings to make them sound worse.

Tvad 2-28-2020
While a bit of an exaggeration, this is true, although tube amplification often sounds better at clipping output level (as @atmasphere has explained).

It’s a primary reason I have suggested Pass Labs Class A solid state amplification (and gently joined by @almarg).

In addition, Ralph has explained in many threads that while tube amps usually have greater **total** harmonic distortion (THD) than solid state amps, they usually have lower amounts of the components of the distortion to which our hearing mechanisms are most sensitive, and which are most objectionable from a subjective standpoint. Namely certain higher order odd numbered components, such as the 7th harmonic. Also, solid state amps typically (but not always) require greater amounts of feedback in the design than tube amps. Depending on the specific design that can often contribute to transient intermodulation distortion (TIM), which can be particularly objectionable and which is not normally specified or measured. And as far as I am aware a standard for how to measure TIM does not exist.

I almost always agree with the insights Ralph provides here, and that certainly applies in this case. At the same time, though, it seems evident that both kinds of amplification may or may not provide fine results depending on the specific amplifier and on how it synergizes with the particular speaker. So my philosophy when it comes to audio is to focus on the specifics of the particular equipment that is involved, rather than on generalities which usually hinge on matters of degree. And the main reason I leaned toward suggesting solid state amplification earlier in this thread is that in the majority of cases small two-way speakers are designed with the expectation that they will be driven with solid state amplification. Which as a result of its near zero output impedance (accomplished with the help of feedback in most cases) maintains essentially constant output voltage into varying impedances. And hence delivers more power into lower impedances than into higher impedances, as long as the amp is operated within its capabilities. I also suggested that among tube amps those having low output impedances (for a tube amp) are likely to be most suitable.

Based on the first of Ralph’s posts dated 2-26-2020 in this thread, though, it sounds like the Salk WOW1 (and other Salk speakers), like the Daedalus speakers I use, tend to be more versatile with respect to the choice of solid state vs. tubes than many others.

Best regards,
-- Al

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I haven't ever listened to Zu speakers, and I couldn't find published impedance curves or other measurements for the Omen models. But based on the specs and on what I've read about them over the years I'd expect them to be very versatile with respect to choice of amplification, while at the same time being revealing of the intrinsic sonic character of the particular amp.

Also, some of the Omen models have 12 ohm nominal impedances, while others are rated at 8 ohms. And while solid state amps will typically have maximum power capabilities that are close to 1/3 less into 12 ohms than into 8 ohms, given the high efficiency of those speakers that won't usually matter. I suppose, also, that from a sonic standpoint there may be some cases where a 12 ohm load might be less than optimal for the 8 ohm tap of some tube amps.

Best regards,
-- Al
 
I had a good chat with Jim Salk, who said that at a recent RMAF show he played his Salk 9.5 towers (8 ohm, 87 db) with no problem from a 30 wpc tube in a 30x30 room. I'm likely going to change my order (I'm going to think about it a bit) to the Salk SS 6M speakers.

http://www.salksound.com/model.php?model=SS%206M 

They're 90db and 8 ohms. They're a lot more $$ than the WOW1's but the amplification needed for decent headroom will be much less; I won't find myself pushed into stratospheric prices for adequate amp power. I'll still get a 30 day trial to see how I like them. (Others on forums are comparing them to Joseph Audio, so I'm optimistic.) As folks here advised, I am *starting with the speakers* but this time, I'm also paying attention to sensitivity.
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That seems like a good change well worth the increased cost.

+1.

Best regards,
-- Al

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@tvad and @almarg  Thanks for the feedback. It seemed like no big deal to Jim, and it makes so much sense from the what you've said. It really was when I made a decision to listen in a larger room and then broke out a spreadsheet (where I listed the costs and details of speakers and the amps needed to drive them -- and then mixed and matched the costs) that I saw that there was no serious economic downside to making a change. The Pass Labs sounds like a good deal, but I think I'll also follow another piece of advice I got which is to "live with the speakers" for a while before trying to match it to an amp. I have some Adcom stuff which will be just fine until it's time to find a deal on an amp.
Look like the 6M are nice speakers. I noticed Salk's Exoctia monitors used Seas drivers but they are about $6000. Those would probably be closer to the Joseph Audio sound since he uses Seas though different models. If you can find  a McIntosh dealer around try their hybrid MA 252 with those speakers. 
I just noticed you're going to use you adcom for a while, good idea just thought I would toss another option you could research.