Thiel Owners

Unsound - what do you consider the low impedance limit of the AHB-2?

@unsound 

I have no problem with massive orchestral works -- Bruckner, Mahler, Stravinsky, Carter et alia playing at concert level through my 3.7s in my 21x20x8' listening room. My two AHB-2 amps don't even blink.

^The Benchmark amps are at the very top when it comes to a lack of distortion within their load tolerance. They are also somewhat special in that their input allows for a variability that is somewhat uniquely accommodating for system matching.  Regrettably, many Thiels have impedance loads that is outside the window of ideal operation for them. The Benchmarks are not designed to work optimally with many Thiels. While I'm hardly the one to make such a supposition, I don't believe that Jim Thiel would have traded his Krell for the current (or lack thereof) Benchmarks. They could very well be the very best amps for different speakers.

tomthiel wrote " your 03 woofers are Eminence and I would love to know the model numbers on those".

Yes, the "67" in the date code indicates the manufacturer is Eminence. Markings: 10KZHG8GX Date Code: 67-7920

 I'll send you more info/photos soon. Thanks!

tmsrdg - yes sir!

sdl4 - remember, I’m an electronics layman

1. Yes, an AHB-2 should drive your 2.2s. Medium-size and real-world are vague and subjective terms, but here’s why I say yes. The (clipping) protection circuitry is so fast and sophisticated that I can see the lights flickering without hearing any dropouts. That takes 100dB in my functionally rather large room. In case you don’t know, my room was weird. I built a resistive-wall (leaky) 4000 cubic foot room within an 11,500 cubic foot floor of a 38,500 building with various openings between the floors. Virtually no modal interactions, but hard to characterize its "size" since the direct space was moderately sized and the larger spaces were acoustically secondary. All that said, my preference and regular use mode was each speaker driven by a bridged AHB-2. But, a single stereo amp was adequate for moderate (85dB peaks) listening.

2. The AHB distortion profile is extremely clean, but I lack technical fluency regarding your specific question. I point you to the Stereophile and AudioScience reviews, among others, to see their qualitatively (stunningly) low distortion. It took me some time to realize that the bass balance was not thin or dry. Other amps (of my experience) add harmonics, especially noticeable in the bass. On a related note, the Benchmark DAC3 and Preamps-4 take additional measures to reduce second and third harmonic distortion. John Sieu’s essays on Benchmark’s site are quite informative.

I don’t know the Atma-Sphere amps, but I do know that the Benchmark class H topology acts differently than do ’normal’ amps, even full class A. JS sent me some distortion graphs illustrating that the 1 ohm profile is virtually identical to the 8 ohm profile. No, that’s not normal, and no, I can’t lay my hands on those graphs or explain the technicalities. But, yes, the amps do sound that way. With JS’s coaching, I rigged an experiment to account for my initial perception of ’better’ sound in stereo than bridged. The output impedance drops to half, lowering the damping factor. I shortened the speaker cables from 12’ (stereo) to 6’ (bridged) and the SQ difference seemed to vanish. This THX amp topology is amazing as tmsrdg said - all that weirdness goes away leaving only the music. Sorry to gush, it’s just hard for me to believe.

BM has a generous return policy in case their power doesn’t meet your needs. Or, if your budget can be stretched, two of them make for serious audio nirvana.

Jeff - you may be in for a big treat! If your woofers are indeed mis-wired, that wreaks havoc with the phase coherency of the whole system. The most certain way to get it right is to get a 6 volt battery (lantern) or 9 volt is OK for woofer with a short-duration test. Connect + to + and the cone should move outward. If wrong, change the leads. I think your 03 woofers are Eminence and I would love to know the model numbers on those. Likewise for the mids and tweeters if you don't mind.

Regarding tweeters, I (seem to) recall the 03 was Polydax and the 03a was Audax which may have been an upgrade or a merger, etc. Rob at CSS may have a more definitive answer. Stay away from an old tweeter. They wear out via fatigue of the tinsel leads. Let us know what you learn.

The silliest question is the necessary one unasked.

TT

@tomthiel   I know you have a lot of experience using the Benchmark AHB-2 with Thiel CS-2.2 speakers, and I'm hoping you can answer two questions about the AHB-2:

1. Are you satisfied that the AHB-2 has sufficient power to drive the 2.2s with ease in stereo mode under any real-world listening conditions in a medium sized room?

2. Do you know what kind of distortion profile the AHB-2 has in relation to second and third harmonics compared to higher order harmonics?

Distortion profile is an issue that Nelson Pass has studied a lot in relation to Class A and A/B amps, and it is also being discussed in relation to Atma-Sphere's new Class D amp that uses GaN-FETs. The Atma-Sphere amp is supposed to have the sweetness of a tube amp with lower distortion, greater transparency, and better masking of higher order distortions. The Atma-Sphere amp has similar power ratings to the Benchmark amp at both 8 and 4 ohms.

Gotta second Tom's Benchmark rec. That's all you need and the end of the story. I run all Benchmark with my 3.7s. It has completely reoriented my ideas about endlessly looking for the right tweak/cable, amp and etc. Of course, I used to do that.  But it seems like such a weird waste of time now, not to mention money.  All these people looking to color the sound in just the right way. There may be yet new caps and resistors for the speakers, but that's another story.

Questions regarding tweeter replacement & driver polarity.

I recently discovered that one of the tweeters in my Thiel 03s is outputting at a diminished volume. In order to troubleshoot I swapped the tweeters between the 2 speakers and the problem persists with the same tweeter, so it’s not the crossover or something else. I looked online and found what appears to be an identical tweeter (Audax brand, the original is Polydax, see link at bottom of post). Has anyone had experience with these replacement drivers? I’ve also found vintage Polydax drivers on eBay but I’m concerned about their wear and tear/condition.

On another note (sorry if this is a silly question): All 3 drivers in my 03 should be wired with the same polarity, right? In my exploration I discovered that the woofers are wired out of phase with the mid and tweeter. The woofers where removed at one point for re-foaming so maybe they where reinstalled in error.

https://www.madisoundspeakerstore.com/audax-soft-dome-tweeters/audax-tw025a1-12x9-1-textile-dome-tweeter-with-ferrofluid/

I recommend getting the Benchmark AHB-2 into your auditioning mix if you can. Once I latched on to its clean, quiet capability, all the way to 1/2 ohm load, I have gotten hooked. Just sayin'

@unsound Just trying to compare my Diablo 300 to the newer Gryphon Essence Monos.

My dealer can lend me the Essence stereo and pre to try out in my system so i can make a shootout against my Diablo 300 but no one has the Mono versions for me to try.

My guess is that the Essence stereo might run out of steam compared to my Diablo 300 but i could be wrong.

My room is medium size.

@Thieliste, it depends on the model Thiels, room, desired volume levels and the particular amplifiers in question. While Class A has advantages with regard to cross-over distortions over Class AB, there’s more to good sound than that alone. Furthermore, many so called "Class A" amps lose Class A output in proportion to increased power output into lower impedances. It's not uncommon for some Class A amps to halve Class A output with each doubling of power output into halving of impedance load. For example, one might have an amp rated as providing 55 Watts per channel of Class A power into 8 Ohms and be able to double down into 2 Ohms to provide 220 Watts of power. If we put such an amplifier on a speaker say with a sensitivity rating of 90 dB @ 2.87V with a minimum load of 2 Ohms, the Class A output of that amp into this speaker at 2 Ohms might be less than 14 Watts and that would be at a 2 Ohm sensitivity of about 84 dB. One can see that it might be quite easy to power out of Class A output and into Class AB power output. The advantages of low output Class A amp might be better appreciated with a speaker with a higher impedance load. On the other hand there are other considerations that might demonstrate that a lower impedance might be more beneficial, just perhaps not as much as with many low powered Class A amps.

@duramax747 

PM me at rsr no space 921 at  live dot com about CS2.7

I posted an image of my upgrade 2.7 woofer board , tag = Thiel scrolled down almost the last system .

I'd say that I am hearing a more forceful and/or quicker low end , one that doesn't weaken or roll off as it goes lower .

 A lot of work and this was the easy board to work on !  

Also the screws holding the boards contained iron , replaced with brass .

@pieper1973  

Sorry to hear about your mishap , are you going to repair or replace ? 

Guys i have a question regarding amp power to max out Thiel speakers.

Is it better to have 300W A/B stereo doubling down to 2 ohms with 136 000 microfarads of capacitance or 55W pure class A Monoblocks doubling down to 2 ohms with 880 000 microfarads of capacitance ?

Thanks.

thieliste

Good to read that the newer Cardas offerings are a sonic match for CS 3.7 loudspeakers. I am on-the-record reporting that Cables do make a difference.

Happy Listening!

😭😭

I killed my amp yesterday😭😭

It is actually my own fault. I readjusted my room and put the amp underneath something else. This may have seriously impeded airflow, the unit was red hot when it failed.. 

So now I have to listen to music on my phone through a desktop speaker system.. at least it's something.. 

Happy listening y'all 😉

Signal cables do make a huge difference from one brand to another with Thiel speakers at least in my experience with my 3.7s.

I have gone from Gryphon VIP IC and SC to Cardas Clear Beyond IC and SC.

The difference is night and day, Clear Beyond cables are in a league of it's own.

The synergy with my 3.7s is mind blowing, never heard such level of weight and clarity in the bass region before.

Musicality is second to none, same with depth, soundstage, air, texture and so on.

Best cables i've ever heard to date by a wide margin and i can even say best component upgrade i've ever done in my life.

^I too have often (perhaps too often) gone on record record here on my strong preference for sealed boxes, not only for bass output, but for overall coherence as well.

You are correct - I didn't cross-check my rusty memory. The CS3.5 bass in its enclosure is 'critically damped' Q.5 for no bass hump, which some critics consider 'dry' or over-damped.

Also my apologies for my final statement of 'excellent in every way'. I meant that the bass configuration was optimized for performance in the phase, time and frequency domains. In particular the EQ'd sealed bass keeps the fundamentals in time with the upper harmonics, whereas reflex bass places the (reflex-supported) fundamentals a full cycle behind the rest of the signal. Lots of controversy around whether such bass coherence can be heard or matters. I'm among those who say it does 'to me'.

Thanks Unsound, your thinking makes sense to me.

Re bright Thiels, it was the one thing I didn't like when I first got my 2.3s, but it can be tamed.  For me it meant that each and every upgrade/improvement had address this, and room treatment amd arrangement (rack to the side wall), careful speaker placement (including height), speaker cables (AZ Holograph, thanks Eric Squires!), and Isoacoustic GAIAs all helped in different ways, the clincher was upgrading the digital source (went with bel canto 3.7).  All the while I was rolling tubes, and one thing I have learned to appreciate is being able to hear most (not all) of these little changes.  One reason I went for Thiels in the first place as a newbie audiophile was bc of their reputation to be very revealing of the signal, as TT mentions above.  I knew I'd be cycling through equipment cables etc and wanted good chances to be able to hear the differences.  Thiels have delivered!

Thanks for all the information you share here, Tom!

Just to get on the right side of Thiele & Small, the term "critically damped" refers to a total system Q of .5, and "maximally flat" refers to the more commonly used .707 Butterworth configuration, which is slightly underdamped and is tuned to use a 3db hump in the bass response to lower the -3db point.

@petaluman - the 03a was a sealed box design which produces a 12dB/octave bass rolloff. I think the tuning was .707 Q which Jim considered critically (properly) damped and some call overdamped. I don’t remember the unequalized -3dB point, but a fit curve could be overlaid knowing that the EQ curve was 12db/octave with the peak centered at 30Hz and then reducing symmetrically to zero boost. I would guess the upper blend point would be around 100Hz. So, without the EQ, your bass will roll off at 12dB/octave below that blend frequency. With the EQ, you get critically damped flat response to 30Hz, then rolling off at around second order. Excellent bass. The EQ did not add cut, it merely ceased adding boost.

The Thiel eq was discrete circuitry and neither the EQ or any Crossover had op amps. However there was an aftermarket product called "Golden Flute" built in a brass tube and powered by a wall wart which used op amps to achieve the same goal. I have heard that they were well liked and successful; but I know nothing about their particulars.

I know of no hot-rodded versions of the 03a EQ. I do know that the CS3 EQ, which performs the identical function, was more sophisticated in its circuitry and execution. And that the subsequent CS3.5 was the first generation to be direct-coupled with no capacitors in the signal path. The 3.5 had variable cutoff points at 20Hz and 40Hz to side-step troublesome deep bass room modes if necessary. The 03a and CS3 families are conceptually the same product - with the addition of the Coherent Source nameplate. Even though the woofers are different, their Thiele/Small parameters and enclosure size are very similar. An EQ for the 03a, CS3 or CS3.5 would work for your 03a as would Golden Flutes for any of those same models. The 01/ 01a/ 01b also has the same 30Hz x 12dB boost and would work. Avoid the model 03 EQ, since that was both ported and boosted, so its parameters are different. I am working on a 3.5 EQ upgrade for significantly better performance than stock.

The EQ transforms the speaker from significantly bass shy to excellent in every way.

@tomthiel Thank you for your recommendations. My ear level is about 36". My room has a lot of limitations, but has a fair amount of absorption and diffusion. There is an equipment rack between the speakers. 

I really like the 3.6s, but I need to love them to keep them. Rob at Coherent Source Service gave me a couple of things to check out to make sure they are functioning properly.

If they are, they may just not be a good match for my system and room. 

I saw the recent references to the 03/03a Thiels, and had a question.  I have a pair of 03a speakers, which came to me without the equalizer.  My understanding is that they only provide a bass boost to lower the -3db point.  Would anyone know what the unequalized vs equalized response curves looked like?  Or at least the -3db points.  Did the equalizer return to flat at still lower frequencies (relying on the natural 12db/octave rolloff), or did it add additional rolloff at 6 or 12db/octave?

Also, I've seen the crossover schematic with the op amps.  Are there any hotrodded versions of the 03a equalizer?

big_greg -I agree with Cascadesphil that Thiel’s can be more sensitive to input signal than most brands. In my opinion, that has more to do with their coherence allowing the ear-brain more scrutiny. But that discussion is beyond the scope of this response. Let’s assume that your signal is fine.

You stated your listening distance as 9’, which is fine. Design distance is 10’, and the closer you get, the more critical your ear height becomes. The propagation triangles have to resolve at your ear. Design ear height is 3’. If you sit high, you will get a treble-heavy and non-time-aligned wavefront. That’s a design constraint of phase coherence with multiple drivers and why Thiel gravitated toward coax treble sources in later models - with their own issues and challenges.

Another critical factor is early reflections, which likewise become more critical in a coherent design. The speakers are designed as point sources with very broad, even dispersion characteristics. As such they require at least 3’ between the tweeter and any reflective surface. Side-wall reflection is most often a culprit; absorption at the reflection point helps - a lot. Similarly, a low ceiling and/or hard floor can be problematic. In a small room, consider a long-wall layout.

Note that Thiel’s tonal balance is tuned for listening off-axis. At design setup the ear is 20° off-axis which is where the power (in-room) response matches the direct response. That straight-ahead position requires at least 3’ to a side wall, more is better, and absorption helps. In my experience most people aim them slightly inward to mitigate side-wall reflections. My experience is that straight-ahead with narrower speaker to speaker placement solves the issues better. Such particulars of setup are far more germane to performance than are particulars of equipment (unless grossly inappropriate.)

Thiels are articulate and precise, and for those who appreciate that, they can be very musically engaging. Many speakers are designed to be forgiving of problems - Thiels are not. Our goal is to faithfully reproduce their input signal - unvarnished. Much like a recording environment must be carefully optimized to capture a proper record of the recorded event, the playback environment must also be optimized. In the hi-fi hobby I believe we could create far more satisfying musical immersion by working on our environment and setup rather than looking to gear changes.

Keep the faith - the results can be wonderful.

"

    
big_greg wrote" If there are other suggestions to tame them, I’d love to hear them."

A gentle amount of EQ will work wonders.

I've owned a few Thiel models.  The newer ones (e.g. 3.7s, 2,7s) don't seem as sensitive to cabling as the older ones (I've owned besides the 3.7s, the 2.3s and the 7.2s).  In addition, when my friend worked at the high end shop in the early 2000s, for about a six year period, I did virtually all his set-ups and installs with him (and those where all pre 3.7s by a few years, 1.6s, 2.3s, 2.4s, 1.7s, 6s, 7.2a).  The 3.6s do have a reputation for sounding bright as do some of the other earlier models (not owned or heard them personally),  I almost went into the cable making difference and have had numerous secondary (non-Thiel) systems currently and in the past.  Many times a cable would make a bigger difference on my old 2.3s for example and something I could barely tell if there was a difference on something like my B&W P6s.  So from my experience (but nothing as old as the 3.6s - but yes to the 1.6s), some of the older models are the poster children for everything in the chain is important more so than some other brands.

I read a lot of reviews about the Analysis Plus cables and chose them in large part because they are regarded as neutral to warm.  I have other Analysis Plus cables farther down their line in use in other systems and those worked great.  Analysis Plus cables are in use for speakers only. The rest of the cabling shouldn’t matter since all my other speakers don’t suffer from this malady.

Speakers cables or interconnects or both?  There's some threads here - e.g. 

@cascadesphil Analysis Plus Black Mesh Oval 9

What cabling are you using?  Sometimes the cables can accentuate or increase brightness.  I had a friend complain about that in a system a year or so ago.  He ended up changing the preamp from what I recall.  I did make him something that tends to be a bit more laid back vs. what he was using cable wise to try.

I purchased a pair of used 3.6 speakers a few weeks ago and try as I might, they are just too bright to live in my system. 

I first drove them with Herron M1 150 watt monoblocks.  I bought a pair of Ampzilla 2000 Second Edition monoblocks to see if they would sound better with more power.  The dynamics improved, but they still sound bright.  The Ampzillas are rated at 300/540 into 8/4 ohms.  Stereo Magazine measured them at 390/680 and they are supposed to be stable into 1 ohm.  

I put my Harbeth Super HL5 Plus speakers back into the system and they sound sublime with the Ampzillas.  They had a little bit of a hard edge at times with the Herron amps, but that is gone with the Ampzillas.

My room is less than perfect, and could be contributing to the issue.  The right speaker is near a side wall, but the Harbeths as well as my KEF Ref 1 and Stirling LS3/6 speakers all work great there.  

I really like everything about the 3.6s except the brightness.  If I could tame that, they might knock out my newer and more expensive speakers. 

My options for placement are limited and I'm not going to spend even more on amplification for 20ish year old speakers.  I had them about 9 feet from my listening position and just slightly toed in.

If there are other suggestions to tame them, I'd love to hear them.  I've also reached out to Rob at Coherent Source Service to see if he has any upgrade or mod options.

"Do you recall the peak Amperes of the KWA 150SE ? This measurement or Slew Rate are strong indicators on the performance of a Power amp."

There are tons of reviews out there (e.g. 

  but need to translate it - explains the differences between the 150 and 150 SE)

I'm not aware of any (review) that has detailed measurements.  I knew of people who upgraded the 150 to 150SE and there are reported large differences.  

The problem with something like that (and remember I still own the LS36.5DM preamp) is of course system synergy.  The other problem is that the design is not really new.  As with anything, technology tends to improve with age.  The 150SE currently lists for $11k.  Probably due to its age and other advancing technologies, it doesn't have a particularly good resale value (e.g. just go to hifishark and do a search of sold ones).  I'd guess the average sales price is around a third of its current retail.  That's fairly low for an audio component that is a current model.

I think that much of the problem is due to the fact that audiophiles have owned it (like me) and tried some of the newer technologies (and my Thiel 3.7s are not an easy load) and realize it is no longer competitive, even at used value.  The ultra high end (e.g. well above the current list price of the Modwright) may be a different story.  Audiophiles, manufacturers, retail stores, etc., tend to live in the past in many cases.  If, for example, they heard an amp of a particular brand and it had a reputation for a particular sound signature in the past (say a decade back, give or take), that tends to stick for a while (I had friends who used to work at retail and that's what they would convey to customers).  All I can say in my system, there is no comparison between the modded Voyager I currently own as well as the modded dual mono IceEdge I had before it vs. the Modwright.  I've had people over familiar with my system and they concurred.

I think audio wise, down the road, we will be dealing with many more speaker products that are active where one only plugs in the source.

@thosb,:

Thiel CS2.3 Loudspeaker Specifications | Stereophile.com

Thiel CS2.3 Loudspeaker Measurements | Stereophile.com

Thiel's recommended power for the CS 2.3's was between 100 and 400 Watts per channel for an amplifiers standard 8 Ohm rated output.  Thiel also suggested a minimum of a 3 Ohm load, how ever as indicated in the 2nd link independent testing demonstrated a 2 Ohm minimum load and with a high capacitive phase angle to boot. 

This all suggests that ideally one would have amplification capable of delivering between 400 and 1600 Watts per channel into 2 Ohms, depending of course on one's room and desired volume levels. Be wary of amplifier manufacturers claims of "being stable into 2 Ohms". That only suggests that the amp won't go into oscillation when presented with a 2 Ohm load, not how much power it will actually provide, or how much distortion will occur at 2 Ohms, or how it good or bad it will actually sound into 2 Ohm loads. I think you'll find that theses requirements will make your short list that much shorter.

Thanks guys.  Good to know re the MW KWA 150 SE, but it's in another league compared to the 100, spec and price wise.  Dan didn't share any details in terms of peak current, his was just a quick response.  I do have the newer tweeters, same as the 2.4s I think.  Guess it's smarter to hold off and consider either the Peachtree or LSA GaN or maybe Audio GD Master 3A or used Ayre.  

cascadesphil

Do you recall the peak Amperes of the KWA 150SE ? This measurement or Slew Rate are strong indicators on the performance of a Power amp.

Happy Listening!

thosb

Thank You for citing Dan Wright's reply to your KWA 100 SE query. Did Dan talk about peak current in (A)mperes ?

Happy Listening!

cascadesphil

Thank You for addressing thosb query on the ModWright gear. I knew that we had a Modwright owner or 2 on the Panel. Class D is a different kind of Amp. Good to read that you are enjoying success with the LSA Voyager.

Happy Listening!

I had a Modwright KWA150SE driving my Thiel 3.7s at one point.  Many moons ago I owned 2.3s and 7.2s after that.  Before the Modwright amp, I had a bunch of Proceed amps (HPA) and Bryston amps (ST and SST series).  I now use a Class D amp (and had a couple of other Class Ds before the modded LSA Voyager I have now) and they all drove my 3.7s better and sounded better.  The 3.7s are a harder load than the 2.3s, but not as hard as driving my old 7.2s.  

As you noted, the room is very important.  Also the way one listens both the type of music and how loud they listens matters.  I can play my 3.7s loud with no issue.  I also have an integrated AV system and still use my Modwright LS36.5 DM preamp for music.  The 2.3s when pushed (do you have the originat tweeters - I believe eventually they had newer ones which were vented) can start to have a bit of harshness.  The 2.4s were a bit better (when my friend worked at a high end shop many moons ago, I did most of his deliveries and installs with him over about a 6 year period - I remember delivering a pair of 2.3s with him and the room was just an awful choice for those speakers - high all glass walls on 2 sides, a stone and glass fireplace across the way and a small wall in between the glass walls with a coffee table at an angle that was used for the components - could not wait to get out of there - hurt my ears).

Has anyone had success driving their Thiels with Modwright KWA 100SE?  Dan's response via email struck me as honest but maybe conservative - he said "The Thiels are a high current speaker and difficult load. The 100SE can drive them, but not as well as a more powerful amp. A load like that might even trigger the amps over-current protection."  Which is too bad bc I really would love to hear this amp.

Currently greatly enjoying my setup of Sonic Frontier Line 1 -> BAT VK-55, which is only rated at 55 wpc but sounds exceptional until 92 dbs or so.  Also tried an NAD M22v1 which sounds too squeaky clean in general but is much better at higher volume levels.  

I have CS 2.3s btw and am still thinking about modifying the xovers as well.  

My two cents on room and speaker placement, just keep experimenting with placement and room treatment.  For me clearing the space between the speakers by moving rack to sidewall and using heavy draperies and/or diffusion on front wall made a big difference.

Thank you Jafant.. same to you and the others

Happy Friday! All

Pico

And … are they Picofarad or Nanofarad? 

Does anyone know the capacitance  of the 6 small polystyrene caps in  3.5’s crossovers?  

In the crossover schematic in my possession the capacitance of these units is not indicated, they are instead identified only with the letter "S" (which perhaps stands for styrene). 

The actual units installed in my speakers have the writing "ASC 12000H" (they should therefore be 12000 Picofarad capacitors, built by ASC Capacitor), but according to what can be found on line these caps should be 15000pf.

Therefore I’d like to ascertain the exact capacitance and brand of the stock units installed by Thiel (in order to ascertain if my capacitors are original or have been replaced at a later time). 

Thank you all 

DIY is different than manufacturing. From 1983 / CS3 onward, all our film caps were custom with a target and a tolerance window, not necessarily symmetrical. Our commitment quantities were in the range of 10,000 pieces spread over the product life. Today we’re doing the best we can. The reason I first steered magnet7 toward 8 is that the original cap was a 7, so I would prefer a 7.8 over an 8.2. But as we say, we play our best with the hand we’re dealt. And the sound will be glorious compared to stock.

@tomthiel 2.5% over target may be so, but I recently sent back five(!) pieces of 6.8 uF caps (CC) because all of them were 7.0 uF.. I would not have minded this very much, were it not that they sell 7.0 uF caps as well.. that for me was reason to send them all back.. and now I'm waiting for Rob to send me five be says he has (and which he says sound excellent..).. 

magnet7 - He is correct, that's 2.5% over target, which is OK.