Ralph,
I understand that you are referring to the approach you use with judicious application of negative feedback. I was referring to Lynn’s comparison to the “golden age “ PP amplifier which typically used 20db of NFB. Your current class D amplifiers do not fit this description.
Charles
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Gents,
I have had several Class D amps in my system in the past 10 years, and the earlier versions of them were dry and lifeless after extended listening sessions. In the last couple of years, I had the VTV Audio EVO 1200 Class D amp with the Purifi module, with the aftermarket ministrations of Ric Schultz, and while the sound was as Ralph describes it, there was something missing in the sound after extended listening sessions. It may clearly be due for my inherent biases, I will readily admit that. After listening to the VTV amp for few months, I swapped back into the rack my McCormick DNA .05 which had their Platinum upgrades and after a few minutes of listening to it, I said to myself... "Ah, what was missing with the VTV amp has all been restored." That is what I experienced, plain as day. I later got the stellar Wells Audio Innamorata SS amp, lovely both in its looks and more importantly in its sonic excellence -- easily the best SS amp I have ever had in my system. After a few months of enjoying the Wells amp, I swapped Don's KT88 tube amp back in the rack and it was easy to hear the difference in SQ... back was the liquid sound of tubes with amazing extension on both ends and a soundstage that mesmerized my ears. None of the sluggishness in sound of my old CJ gear, which was appealing to my ears, but far from an accurate sound reproduction, so Don's KT88 amp had all the advantages of a SS amp but had the warmth, richness and liquid sound that I desire which serves to envelope me in the listening experience (which I agree my VTV amp did to a degree initially) but here is the difference: after hours and hours of listening, I loved even more the sound for the KT88 amp, whereas in extended listening sessions, there was a lacuna in the sound with the VTV amp that I clearly sensed and missed.
That said, my new 300b monos are a quantum leap forward in SQ even compared to Don's KT88 amp in all respects and most noticeably this: it sounds as if there is no amp at all... just glorious music enveloping the room, with pure tonal and timbre correctness that astonishes me... and absolutely dead quiet. As good as the Kootenai is, and it is a stunning and powerful 65wpc tube amp, the 300b monos are in a whole different realm.
I have not heard the fairly-price AtmaSphere Class D mono's at any audio show, but as Ralph has come from a tube-centric point of view, I must acknowledge that he might have be on to something with his design, surely he is. There are lots of advantages to using a Class D amp and God bless those that love them.
This erudite conversion with Lynn, Don and others has been a deep dive into tube design philosophy and I personally am hearing the splendor of their creation moment by moment, lucky me, for darn sure. Again, and not to be disputatious on this wonderful thread, for the liquid euphonic and most natural presentation musical reproduction with my new 300b monos, I am still firmly in the tube amplification realm as it recreates music in such a realistic way, so pleasing to my ears. The hell with the heat the 300b monos throw off!
Now, with another 100 hours on the amps, I will amplify the comments I made in my OP--- these amps are the most stunning addition to my 50 year quest for more accurate and pleasant sound in my system.
I am driving my 86db efficient CSS Audio Criton 1TD-X speakers with the 300b amps at the moment and I can play music as loud as I can possibly tolerate it with no sense of distortion or clipping. I have a 8 wpc Willsenton 300b integrated amp which I drove the same speakers with and it got pretty distorted as I rotated the volume knob to the right. I recall that Don said that his mono's sounds "like a 100 wpc amplifier" and he is exactly right.
Boys, you are going to have to pay to play with Don/Lynn's new monos, but it is clear to my ears that if you are looking for an end game in amplification... and have the appropriate synergy with your speakers, then I hope you get a chance to hear them, which I will in the Spatial Audio room at the Pacific Audio Fest this month in Seattle, along with Don's new companion tube preamp.
I have a pair of Cube Audio Jazzon single-driver speakers arriving on Monday which I think will be a stellar match for the 300b monos, but still the the mono's have made my Spatial Audio Triode Masters sound the best they have ever sounded, by far. To be candid, if I had had the new 300b monos, driving my Triode Masters, before I ordered the Cube Audio speakers, I don't think I would have ordered them so as the Triode Masters sound so fantastic. Don Sachs encouraged me to buy them ~6 years ago and now he has as his reference speakers the Spatial X- speakers, clearly an upgrade from my Triode Masters.
I live in Sacramento and would be happy to invite music lovers to come and hear my Don Sachs gear and my Cube Audio speakers. Send me a private message and let's hear them together. Cheers!
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@whitestix
Now, with another 100 hours on the amps, I will amplify the comments I made in my OP--- these amps are the most stunning addition to my 50 year quest for more accurate and pleasant sound in my system
I believe you. These amplifiers with your Cube Audio Jazzon is going to be a sublime pairing.
Charles
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Charles,
As a 300b amp owner yourself, you know whereof I speak. Expect a report back on this thread in due time when the Cube speakers are run in. Some folks agree that Cube's driver technology is one of the biggest leaps forward in speaker design in a long time. I heard them at Axpona and was compelled to have them in my system.
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@whitestix
A friend has owned the Cube Audio Nenuphars for over 4 years and simply loves them. They’ve taken full range single driver speakers to a very high standard of performance.
Charles
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At the expense of a small technical quibble, I don’t see Class D as entirely analog. Without the pulse-width modulator, it is a 100~500 kHz AM transmitter that transmits a silent carrier. The pulse-width modulator is what makes the whole thing possible ... the pulse widths are precisely (and I mean very precisely, down to parts per million) 50% positive and 50% negative, if the input is zero.
Deviations from exactly 50/50 alter the pulse widths (to 51%/49% or any other ratio) but the pulses themselves are rail-to-rail, and the output devices are purely switches. It is a modulation system like AM or FM, which are also analog, but it is a modulation system nonetheless. Without the PWM modulator, there is no signal that can get through the amplifier.
Class D has been around commercially since the early Seventies. The trick is extremely fast switching with no overhang, resistance to load reactance, and a (very) low-distortion modulator. An FM transmission chain that achieves less than 0.1% distortion is at the limit of the art, and PWM modulators inevitably have their own set of distortions. PWM is not inherently distortionless, any more than AM or FM. Yes, it can be transmitted, but it would be very sensitive to multipath and group-delay errors ... both would cause distortion. With both FM and PWM, small time errors translate into amplitude distortion after demodulation.
Interestingly, SACD/DSD, at the native 2.8 MHz switching rate, is a type of quantized PWM. Since the pulses of true PWM are variable width, they cannot be recorded on digital media. DSD uses dither encoding and digital feedback (noise shaping) to quantize the PWM pulse train into fixed widths and provide the closest approximation to true PWM on playback.
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Show Update: Don, myself, and Spatial team will be at the Seattle show. What you will see and hear will be pre-production prototypes, sonically close to what we plan to manufacture. I can tell you neither Don, nor I, will tolerate any backward steps in sonics. I’ve lived with original Karna amps since 2003, and they remain my personal reference standard. The production amps must match or exceed that standard.
Prices, and names, are still up in the air. I call the preamp the Raven, and the amps Karna Mk II’s, or Blackbird, depending on my mood. Don calls them the Statement 300B’s. Spatial will probably come up with own names for the preamp/amp combo. Don and I are encouraging people to buy the set, but they are flexible enough to interface with industry-standard components.
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Whitestix,
What the heck is a VTV EVO 1200 class D amp with Purifi modules? Never heard of such an animal....he he. You must have your nomenclature confused. What VTV product did you REALLY have? Yes, I mod the VTV amps (Purifi, VTV D300 digital amp and Ncore Nilai).....so am very familiar with all the types and possibilities. Maybe I modded yours......but it was not an EVO 1200.....he he......it don't exist.
Sounds like that 300B amp is killer......me...enjoying the heck out of my modded VTV D300 amp pure digital amp......no DAC, no normal analog stages.....just....very pure sound.
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Well, I read the Quanta article and I’m not sure if I enjoy my home audio set up or if I’m just imagining I enjoy it… but maybe the reality is that it would be better either way if I had the new amp and preamp??
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Ricevs,
Pardon my incorrect reference to my amp: it was the VTV AMPLIFIER Stereo Purifi Audio 1ET400A Amplifier. The guy that bought it from me was over the moon happy with the sound of the amp.
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Snapsec, the unstated point of the Quanta article is that objective reality cannot be experienced directly ... the entire ear/nervous system/brain/mind system processes everything into mental images and impressions.
This is no little man watching a movie theater inside your head. It’s all signal processing, from the neurons in the ear to everything else, continually pattern-matching against memory, expectation, and emotion. Surprisingly, the brain can actually physically alter the hair cells in the cochlea with feedback mechanisms, altering perceptions right at the sensory level.
This is happening all the time ... there is no such thing as passive listening. For that matter, hearing and signal processing are still going on as you sleep, ready to wake up the rest of the fight-or-flight mammalian brain at a moment’s notice. Over the last 30,000 years, the powerful social experiences of speech, story-telling, and music gradually overlaid our mammalian brains, and made our species into the humans we are now.
This is why the notion of an Absolute Sound is inherently absurd. That’s like saying an Absolute Dream, or Absolute Taste. The entire hifi system is an illusion (and emotion) generator, and the quality of the illusion depends a great deal on the set and setting of the listener ... at that moment. Considering how vastly different our individual realities are, it’s amazing we can agree on anything at all.
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@lynn_olson
This is why the notion of an Absolute Sound is inherently absurd. That’s like saying an Absolute Dream, or Absolute Taste
Hmm, Well if that’s the case how do you determine or judge the sound quality of reproduced or recorded music via electronic audio components?
How did you reach the conclusion that your amplifier sounds “right “?
A reference point is needed to evaluate and judge against. In my opinion the late Harry Pearson was right when he strongly advocated listening to live acoustic instruments and human voice.
What is a more thorough/better assessment of an audio component than a comparison with an authentic instrument (Un-amplified)? Are you exclusively reliant on your test measurements and dismissive of actual listening?
How do you determine your products mimic or come close to the sound of a real cello, saxophone, piano or human vocalist? I’m genuinely curious as to your approach striving for sonic realism (If you believe that it even exists).
Charles
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Such an interesting thread. If I could only hit the Lotto I'd get in line for the coming Spatial amps, pre amp, and a quad of new W.E. 300B's.
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In relation to what @lynn_olson is sharing about the listening experience being a stimulus and the impression that can form resulting from the stimulus being encountered.
I have on many occasions been an invited party to offer a 'pair of ears', and to offer a assessment of how a New Design is evolving. There are devices experienced that have been built in parallel and a early prototype is kept as such, with a second prototype undergoing changes to see where there is improvements to be discovered. This method is sort of similar to a modern Photo Editing Software Tool where at the Click of a Button, the before image is immediately viewed.
There are also devices that are sole builds and the experiences of receiving demo's a a result of changes being made are in theory a variant of a previous device used. Much of this is reliant on recollection of previous experiences. This as a method is also quite dependent on the demo's not be too fart apart and the other devices in the system being consistent and not being exchanged.
Relating to the first method, it is much easier to identify if the ongoing work, is able to create a improved impression. It is also much easier to suggest trying out a different supporting ancillary as the two Prototypes at hand enable a very useful evaluation of how the exchanges interface with other ancillaries.
Relating to the second method, I find written records of how the demo' was able to impress and sharing through discussion where it has been perceived attractors/repellents are present is a constructive approach. Follow up demo's usually reveal differences are developing, and where there is betterment being perceived.
There will be a time that a divisive situation evolves, as individuals are unique in their preferences for a sonic. The Range of Attraction for Lean/Transparent through to Overbearing/Muddy is what sets all individuals apart. No one can tell an individual where there attractors/repellents are in the scale, they choose these themselves.
When it comes to buying a Device designed/built by the hand of a Trusted EE with Time Served Experience in producing audio devices, it is not just the realised product being bought into, but the designer/builders philosophies for audio reproduction and their IP, the hooks utilised to create the sonic on offer.
It is no secret such IP is classed as a asset, is their not Circuits that when, investigated there are no values to found on components, the printed info is removed to protect the design from being easily plagiarised.
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Reviewers and consumers are at a great disadvantage in assessing the sound of a product, because they have never directly auditioned single-parameter changes. For example, a change in operating point (quiescent current) of 20% up or down, or a shift in topology in one part of the circuit. I grade these with a simple metric of:
1) No audible change, or at least nothing at threshold level
2) Different, but neither better or worse, just different
3) Worse (and how quickly is it noticed ... 5 seconds, 5 minutes, or an overall quality of discomfort or dislike)
4) Better (how quickly is this noticed, or is it a change in mood)
There are probably twenty or more points of adjustment in an amplifier or loudspeaker where these changes can be made. Some affect measurements, but most don’t ... they’re purely subjective. Also, conflicts can occur ... a better measurement may result in worse sound. At that point, something has gone wrong, and you need to stop and see where you have gone off-track.
We have to address what can be measured at the current state of the art and what can’t. Here’s just one example: for the the purposes of electronic design, nearly all modern capacitors are perfect. There is nothing to choose between them except voltage capacity and long-term reliability. Distortion is vanishingly small, at or below the threshold of measurement.
But ... in a high-resolution system, they all sound different. They are not neutral sonically. Mylar sounds different from polypropylene which sounds different than Teflon which sounds different from waxed or oiled paper. Metallized film sounds different than solid foil. In a vacuum-tube circuit, there are circuit nodes that actually exaggerate the coloration. Worse, DA, DF, self-inductance, or even price have little or nothing to do with sonics.
Perhaps worst of all, the notorious "burn-in" phenomenon where XYZ parts sounds really bad for the first 5, 10, 20, or 50 hours. With no change in DA, DF, or distortion measurements, and no plausible physical mechanism responsible for this. Anything that slow must be electrochemical, but what is it? Just a lot of hand-waving and supposition from the manufacturer, with no data to back it up. But plainly and clearly audible.
Not only that, some parts have essentially no break-in at all (paper and wax) while others can take 50 hours or more (polypropylene or Teflon). No explanation offered, no measurements, no underlying physical mechanism. Well, it’s not ghosts or psychic energy. It’s physics. But what physics? Nobody’s saying anything.
In loudspeakers and vacuum tubes, break-in is real, measurable, and the reasons are well-documented in papers going back to the Fifties. Caps? Nope. Why does copper wire sound different than silver? Again, no explanation. I accept this, but it is not satisfactory. Something is going on, and it is not self-hypnosis or expectancy effect. Often, the most expensive part sounds the worst, and the cheapo part sounds quite good.
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A Friend who helped me source my Valve DAC, at one point was into heavily modifying a few CDP Models from the Sony Brand.
It was my introduction to these Modified CDP's being demo'd through Bespoke Built 300b mono's and Horn Loudspeakers, that were the first digital sources to arouse my interest in digital as a source.
I heard these in all their evolving guises and was even able to have extended home loans, which ultimately ended up with my decision to have a Digital Source added to my system.
One Sony Model had the Highest Quality Caps and Resistors used and lots was going on with how the Valve Stages were designed as well.
There was 'creme dela creme' mod' to be carried out that was inclusive of the use of OCC Silver Wire purpose produced Tranx's. When these were incorporated to the design, there was no Run In period that could help, the sonic and attractive impression that was recognised, plummeted from presentation, the overall presentation was perceived as forced and in ones face, quite unattractive and certainly not able to create a settling down and softening of a mood.
When this same individual producing the CDP's had his GM70 Mono's built. I was again being asked to assess them with him. I thought they were sharing noticeable traits in how I recollected the 845's were able to present.
The GM70 owner convinced themselves there were more to be extracted and carried out Mod's on the Amp's. I was again asked to visit and take part in a listening and assessment session, to which I agreed to when the Amp's had a minimum of a 100 hours on them in their new guise. In my view, the Amp's had become lesser, there was from recollection, some of the earlier impression made, now at a place where I was trying to work out where the changes were and why the presentation had lost much of its allure.
As said earlier, when carrying out such demo's with others, there is a time when the opinions will be differing, I held my tongue, and agreed that if the changes made had been satisfying to the end user, then this is the ultimate goal, I politely made it known I had recognised changes had occurred.
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I have had situations with break-in on my own amps, which are very revealing of parts quality, where the sound got better and worse on a two-hour cycle. While there was an overall upward trend, the up and down kept going on, with the cycle timing varying between a half-hour and two hours. At the twenty-hour mark, I finally lost patience and threw the questionable parts in the trash. That experience has made me wary of all parts that require subjective break-in.
My rule now is twenty to thirty minutes, tops. If the part can’t make up its mind in that time, in the trash it goes, no matter how expensive, or what the reviews say. I don’t want unstable parts in my system. Now if the fancy audiophile part requires a half-hour on a burn-in gizmo, fine, but I will regard it with some suspicion.
I think audiophiles and reviewers are too tolerant of this hokum. If it sounds bad for days on end, it is bad. Something is wrong. There is a design or fabrication error.
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I understand that you are referring to the approach you use with judicious application of negative feedback. I was referring to Lynn’s comparison to the “golden age “ PP amplifier which typically used 20db of NFB. Your current class D amplifiers do not fit this description.
@charles1dad
They don't! However, Futterman claimed 60dB of feedback in his OTLs. That was during the 'golden age'... Also Kron-Hite made a transformer coupled tube amplifier (UF-101) that claimed even more feedback! It was built for laboratory use but works great for audio as well. Its specs are astonishingly impressive and having had a set (they were single channel) I can say they sounded quite decent. That was a long time ago but we compared them to an ARC amplifier which got its doors blown off.
If feedback is applied properly it is really beneficial. If its not then it will mess things up with the amounts normally found in tube amps (12-20dB...).
In the last couple of years, I had the VTV Audio EVO 1200 Class D amp with the Purifi module, with the aftermarket ministrations of Ric Schultz, and while the sound was as Ralph describes it,
@whitestix I'm going to contest this; I was not describing those amps at all and haven't heard them. You can tell something is up that isn't right since when you go on the web, you see really variable reports about their 'sound'. I notice that doesn't happen with tubes- everyone agrees that tubes sound smoother and often have more detail and so on. To what degree and what emphasis is the differences between the tube amps. I'm saying I've been playing a class D that you would think is in that category if you heard it. Going back to tubes you don't find that tubes are bringing anything more to the party. I get that seems like a tall statement. Keep in mind that OTLs have ruled the roost in the transparency department of the tube amplifier world and I've been building them since 1977 or so. During that time I've heard many tube amps; I repaired audio for a living as I put myself thru college and afterwards until Atma-Sphere was able to keep me busy full time. So I know what tubes bring and I'm telling you there's at least one class D out there that does the same thing. I suspect there are others.
Sorry I won't be able to participate in this thread for a while- I'll be out of town for 4-5 weeks. Y'all have fun and be well!
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I've lived through many new equipment break-in events over the years. As my experience level increases and the resolving capabilities of my system increases, it has been easier to track changes through the duration of the event. In a moment of judgement, it can be difficult to make statements of progress or regression as we aren't very good at making absolute comparisons, unlike numerical measurements. It's always relative and our powers of perception are better at establishing trends over time than snap judgements. It is possible to fool yourself in a single session. More valid impressions form through multiple sessions.
Here are several notable examples where break-in from new was significant and long in duration.
Antipodes K50 Server. From new, un-listenable for 9.5 days of continuous power up. Utter dreck. By two weeks of on time the performance was quite good. After 1 month, exceptional. After 6 months, fully plateaued. My experience, corroborated by others, and the manufacturer. The reason - power supply capacitor break in.
Daedalus Apollo 11 speakers. Pretty rough on arrival. Grainy HF. Over days the bass would come and go. By 110 hours the sea began to part. The grain and hearing fatigue began to lift. Bass came in. By 150 hours they were quite good. The manufacturer claims 400 hours for full break in. Guess my hearing isn't that good. Mundorf capacitors are the main culprit here.
Taiko Extreme music server. Sounded OK on arrival. After a couple weeks, quite good. After 1 month exceptional. Here's the rub on this one, even after fully broken in. If you shut it down for 15 minutes, unpowered, it takes 4 hours to recover. If you unpower for over 1 day, it takes 4 days to recover. All of a sudden the drapes open and it's a nice sunny day. These experiences are corroborated by the manufacturer too. Cause - power supply capacitors.
The common ingredients in these events are the capacitors. I suspect that these parts are the special sauce that makes this level of performance possible.
I have not heard a power amplifier exhibit this extreme of behavior from new, but that does not mean these parts don't require break in and overall performance will benefit from more run time.
If you are throwing parts in the bin after 30 minutes, I think you are missing out on some opportunities.
I've read plenty of attempts at explaining why parts, particularly capacitors change during break-in (they do plateau, they don't keep changing) but it doesn't matter unless you are a capacitor designer/manufacturer. Results are results. The reasons why don't matter for users.
Engineering is the prostitution of science. Even scientists don't have all the science worked out yet. Not even close.
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My concern is reliability and unknown, undocumented processes going on in critical components. This is just bad engineering. Imagine an expensive car where the horsepower and handling changed from day to day, and the manufacturer had no idea why. Cars are 100x more complex than an audio product ... the average car has 35,000 parts, 5,000 of which are moving parts, nearly all of which are critical to performance, reliability, and safety. A single-part failure can make the entire car useless.
What’s the capacitor manufacturer’s excuse? "This is how we’ve always done it" isn’t good enough. "We don’t understand what we are making" is even worse. There’s good engineering, making reliable products that people enjoy, and bad engineering, where mysterious things occur and nobody knows why. Regrettably, this is the situation for much of high-end audio.
For all I know, Don, Thom, and I might end up designing a capacitor conditioner for one of the cap companies. Back when I was working with Gary Pimm, he came up with a gizmo that did that ... pushing through 10 kHz square waves at 1/4 of the cap’s rated breakdown voltage. After twenty minutes of that, it either survived or not. Actually, nearly all survived, and they were "broken-in" for sure after that treatment. And it weeded out the parts that were going to fail anyway.
By contrast, using the cap in a normal circuit, with music stimulus, is barely tickling it. No wonder it takes forever.
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My concern for the customer experience might sound big-hearted, but actually it’s purely selfish. Neither Don nor I want ’em coming back. I am 100% retired, Don is thinking about it, and we both want the preamp and power amp to be reliable and good-sounding right out of the box. People tell their friends, etc. etc. So every part going in has to earn its keep in terms of reliability and sonics.
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A Cornell Dublier engineer once explained to me that the difference between a 150V rated cap and one rated at 175V was the way the cap was formed up and nothing else. Forming is a process where voltage is applied to the capacitor with a target of the rated voltage; something that is done only once in the factory.
But the cap is almost never used at the forming voltage. Usually for best reliability, they are to be run at about 80% of the rated voltage.
So the cap is not as efficient at the new voltage when new. It takes time for the cap to 'form' to the new voltage. Its important to understand that electrolytic caps have some properties in common with batteries and so are fundamentally different from film caps in this regard. Charging them and polarity are two examples of this similarity. Forming is one way they are unique.
Anyway, when the cap forms up to the new voltage used inside the amp or preamp it will be a more efficient bypass. Its my theory this is what people hear during break-in. I've found it measurable too- the voltage once the caps are formed is every so slightly higher and the supply is less noisy.
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@atmasphere
So the cap is not as efficient at the new voltage when new. It takes time for the cap to 'form' to the new voltage. Its important to understand that electrolytic caps have some properties in common with batteries and so are fundamentally different from film caps in this regard. Charging them and polarity are two examples of this similarity. Forming is one way they are unique.
Anyway, when the cap forms up to the new voltage used inside the amp or preamp it will be a more efficient bypass. Its my theory this is what people hear during break-in. I've found it measurable too- the voltage once the caps are formed is every so slightly higher and the supply is less noisy.
Ralph, this is believable and logical.
I recently had a DAC built and delivered to me from Ukraine. The builder (Abbas Esoteric Audio) told me that it will require roughly 200 hours minimum of burn-in time to sound its best. He specifically cited the Blackgate capacitors utilization as the reason. He explained to me that it takes time for these excellent electrolytic capacitors (His opinion) to form.
Sounds right to me based upon my experience with his DAC.
Charles
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Ralph,
Your comments on this this thread, as on any thread, are extremely informative. I have not had the pleasure of hearing your new affordably-priced Class D monos and maybe they will be playing at the Seattle show later this month so I could hear them then.
You have had a career as a designer and builder of tube gear. You now are selling a Class D amp with the new GaN technology. Don and Lynn of course are solidly tube amplification adherents, make no mistake about that, but you seem to be straddling the line between an affinity for tube gear as well as Class D amplification.
Are you at the point where you feel your Class D amps are equivalent to your best tube amps? I have long anticipated that the day will come where the march of technology might render tube gear obsolete, but in the main at the moment, my experience with Class D amplification is somewhat akin to the unwarranted adoption in the 60s of lousy sounding solid state gear (everybody made a variant of it) over tube gear that took a very long time for the industry to recover from. Tube gear, like vinyl sales, are better than they have been for a long time, but I remain dubious that Class D amps yield the same sonic goodness after extended listen sessions, than the better/best tube amplifiers. But then I have not heard your new Class D monos. Comments?
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Lynn…. I really appreciate two comments… illusion generator… and the layman disadvantage of not hearing individual part changes…. both of which help explain why many of us go through a bunch of gear trying over and over to improve the illusion.
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Are you at the point where you feel your Class D amps are equivalent to your best tube amps?
@whitestix Yes. After extended listen sessions as you put it I don't find that our tube amps bring anything to the party that the class D doesn't. I really doubt that we're the only ones that can do this so this has led me to thinking that tube power amps are on borrowed time at this point- that is if sound quality is the only arbiter. People do like the glow of tubes- so do I. But I've found also that I don't miss them in the slightest, despite liking tubes so much as to make a business of them.
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There’s nothing quite like twiddling with a speaker crossover or the critical components on an amplifier. That brings the guesswork to an end. You know what increasing the slew rate of an amplifier sounds like ... it’s a pretty distinctive sound, actually. Likewise, if the tweeter crossover is screwed up, you hear tweeter distortion ... lots of it.
Which makes show-going by and large an unpleasant experience (although I love to meet people). I walk by a room, without going in, and I hear problems. Big ones. Multiple problems. And yes, I know how to fix them. But I’m not going to do it for free, and besides, most exhibitors really don’t want to hear unsolicited advice from a notorious busybody like me. So I just keep on walking. There might be one, two, or three rooms where the equipment is working OK, and I’ll spend most of the show there.
This might sound cynical, but seriously, I’ve been designing speakers since 1975. I can’t stand speakers with wonky response, multiple resonances, or gross distortion. And that’s most of the famous-name speakers, so they’re out. And they certainly don’t want to hear my wisecracks at first hand.
I got into tube-amp design around the early Nineties, and joining the staff at Vacuum Tube Valley was a fabulous learning experience, especially from Charlie Kittleson, a great guitar player, and John Atwood, an engineer’s engineer, having worked at Intel, Tandem Computing, and Apple. Sadly, Charlie passed on around 2000, but I’m still good friends with John Atwood. We’re both big fans of the history of technology, and can talks for hours on end about AC distribution systems in Japan and the arcana of NTSC, SECAM, and PAL color television. His current project is restoring a TeleType machine ... because why not? He’s also a ham radio enthusiast who builds vacuum tube rigs from scratch.
At any rate, those of us who do this for a living (although I am technically retired) can spot design errors pretty much immediately. My background is speakers and electronics, which also means I cannot ethically review anything, because all I would do is criticize, which isn’t fair to the manufacturer. Besides, the various designers all disagree with each other ... my designs are completely different from Atma-Sphere, or Audio Research, or Krell, etc. etc. We are all very opinionated.
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Lynn,
My local tube tech was good friends with Charlie who lived near Sacramento and he had immense respect for him. He published a magazine which I am sure you aware of, 100% tube centric. I never met him but he was a legend in this neck of the woods for his tube knowledge.
Ralph, it seems curious to me that knowledgable audiophiles would rely on anything but sound to be the arbiter of their purchase decisions. Tube gear is a hassle and costly, but to my ears, it is the price to pay for such magnificent sound. I think buyers buy tube gear because it sounds better, pure and simple.
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Charlie reached out to me and asked if I would like to be Technical Editor of Vacuum Tube Valley, and I happily agreed. First class bunch of people, including the irrepressible Eric Barbour, one of the most notorious curmudgeons in the industry ... he made me look like a mild-mannered moderate. But all of them were, and are, great people.
Back when I was on the Editorial Board of Positive Feedback (a few years earlier), Eric sent in an article so outrageous that we couldn’t publish it, but it was the funniest thing about the biz I had ever seen. No, it still can’t be published, here or anywhere else. We’d get sued for sure. Eric is one of a kind.
Well, OK, there’s Harvey Rosenberg, but his sense of humor was much more gentle. Meeting him in person at the Consumer Electronics Show in the late Nineties was pretty memorable. He would drop the clown act and get quite serious, but if he saw someone he recognized, he do something outrageous right on the spot, then switch right back. The clown act fooled a lot of people, as it was meant to. He was a very sharp observer and knew what was going on.
Once you get away from the oh-so-serious gatekeepers, there are some remarkable people you meet in the biz. The fun thing about Eric, Harvey, and myself is we were outsiders, and we didn’t have to take it seriously.
Frankly, that was part of my motivation to design the Amity and Karna ... to show, by example, that things could be done differently. At the height of the SET mania in the Nineties, Harvey was the only one who (very strongly) encouraged me to follow my own path. That encouragement, from an old pro like Harvey, made all the difference.
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I have had the matching preamp running quite nicely for about 10 days and I will say the combination doesn't sound like anything I have ever heard. First off, with my 97 dB speakers you literally have to put your ear to the woofer to know the system is on at idle (no hum). The tube rush (hiss) varies with tubes used, but you pretty much have to have your ear to the HF driver to hear that at idle. We are talking a Lampi Pacific DAC with DHT output stage feeding a tube preamp, which feeds the 300b amps. All tubes and at idle it is as quiet as solid state. This gives a totally black background. Lynn went his own way on the circuits and between the two of us we have turned them into working prototypes that are closing in on production models. The working prototypes are what will be shown in Seattle. Again, I hope many folks reading and participating in this lovely thread are able to come and hear them and give an honest opinion. They do not sound like anything else I have built, or even heard.
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I was proposing "Blackbird" as a product name for the amps, and Don said it is not just black like a raven, but "Intergalactic" black, which cracked me up (literal LOL) when he told me over the phone. Looking forward to meeting him at the show in person.
I can say the Amity, Karna, and the new amps sound nothing like other tube amps, whether SET, OTL, or conventional, or like transistor amps, either. I find them hard to describe, partly since I’ve been so close to them for the last twenty-five years (the first Amity came to life in 1998 or maybe earlier).
I’m trying to think of parallels ... maybe the first time you heard an electrostatic speaker? Kind of like that.
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just get yhw alternative 2a3 maybe in paralel
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Don, looking forward to seeing you at the show with your working prototype.
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Why the radio silence folks??? Where are the impressions from the show? Inquiring minds wanna know!
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The show mentioned in this thread is in 2 weeks. There was very little at the LA show this past weekend in the way of 300b. One that had promise was very nice japanese 300b paired with Songer field coil speakers. But the speakers were only 93dB and every room was playing very loud to keep up witht he volume in the other rooms and the amp was literally turned up to the stop. It didn't even sound like a tube amp to me. I would have loved to have heard it at 1/3 volume.
Jerry
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@carlsbad2
Good observation. Over the years I have attended my fair share of high end audio shows. For the most part I have enjoyed these experiences quite a bit. I do get annoyed with the high volume level demonstrations. Personally I do not fine these displays impressive. Even with the very high powered amplifiers driving difficult to drive speakers.
Good quality music sounds better on a good system played at what I consider reasonable listening levels. I do not understand the attraction of the “crank it up” approach.
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I like to listen at the volume a live performance would be at. Obviously, Pink Floyd concerts would be loud, but a jazz combo should sound like you are in the club at normal levels, not screaming at you. I will try to play at various levels when we demo and I have the remote:) June 23 is the show. I know a few folks who say they are attending, so I am sure someone unbiased will post an honest impression. Listening rooms at shows are often hard to tame as well, so we shall see what we can do when we get there.
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Yeah, no way of knowing what Seattle will sound like. Might be stunning, might be not-great, no way of telling in advance. Shows are unpredictable.
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Hi @carlsbad2, thanks so much for coming to see us at the show! The amp was only pegged like that so that we could then easily control the volume from software - but you were hearing it at a fraction of full output, less than half. It just helps so much with running the room smoothly. Cheers, come see us in Seattle in a week or so! We’ll be paired with a Whammerdyne statement 2A3 amp, it should be pretty special...
Best,
Ken
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Lynn,
Oh yea of little faith... Very few speakers play nearly as well as the Spatials in less-than-perfect rooms and your front end will be tremendous so great sound is a foregone conclusion. Your room is gonna sound sensational and I am going to be there to hear it. Lucky me.
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Hi @charles1dad
I couldn’t agree with your comments (below) more. In theory, reproducing music at concert levels sounds like a good idea. In practice however, I think that for anything other than a string quartet or solo guitarist, live concert levels would violate OHSA regulations.
My wife was trained for the Broadway stage, and when she belts it out in our listening room, it's LOUD. She still has a wonderful voice but it can be a bit too much in a small space. Back in the day, you were trained to reach the back of the auditorium without the benefit of a microphone ;-)
I’m all for rock and roll but I also like my hearing, and loud demos are more frequently than not a sign of an unimpressive system.
One little secret of better systems (especially horn or electrostat based ones) is that the resolution level is such that lower level listening can be quite satisfying.
People conflate horns (for example) with playing loud, and they surely do that, and with low distortion. The real benefitis that they’re superb for late night listening.
... Thom @ Galibier
Good observation. Over the years I have attended my fair share of high end audio shows. For the most part I have enjoyed these experiences quite a bit. I do get annoyed with the high volume level demonstrations. Personally I do not fine these displays impressive. Even with the very high powered amplifiers driving difficult to drive speakers.
Good quality music sounds better on a good system played at what I consider reasonable listening levels. I do not understand the attraction of the “crank it up” approach.
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@thom_at_galibier_design
I completely understand the example of your wife’s vocal power/control. At one time I played and studied the trumpet. As with any instrument you have much control over the volume you wish to provide. If I wanted to I could blow people out of a decent size room with just that single trumpet. The thing is that horn sounded just beautiful played at moderate and lower levels.
As you mentioned, audio system resolution seems to be the key factor. As this aspect of my system improved over the years I discovered I could immensely enjoy music at lower SPL levels. I’d say a very good parameter for a system is how satisfying is it to listen to at low and moderate volume?
No question however, to each their own choices. I know that some like to listen regularly at SPL of 90db and above. Their ears and enjoyment be served. It just isn’t for me.
Charles
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I know that when I have my system "cranked" and I measure the level it is about 81-83 dB. I rarely listen at that level. As was stated above, the hallmark of a good system is that it has enough resolution and balance that it can be enjoyed at low to moderate volumes. There is a minimum level for the bass to pressurize or load the room, but that isn't all that loud in any house I have lived in. I generally listen at the level where that has happened and not much higher.
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I know that when I have my system "cranked" and I measure the level it is about 81-83 dB. I rarely listen at that level. As was stated above, the hallmark of a good system is that it has enough resolution and balance that it can be enjoyed at low to moderate volumes. There is a minimum level for the bass to pressurize or load the room, but that isn’t all that loud in any house I have lived in. I generally listen at the level where that has happened and not much higher.
Funny how our perceptions change as we traverse through time. At 25 years of age, I would have considered 83dB to be a mere whisper, and now I (like you) consider it to be quite loud, although I don’t think of this as concert levels ... maybe coffee shop concerts, where the performers are implored to turn it down, so everyone can talk over the music ;-)
This brings up a related a rabbit hole into which we can jump - the perceptual difference between hi-fi reproduction and home listening. Lynn touched on this above.
Thom @ Galibier
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Don and Thom,
Gents, with all due respect, an 81-83 db SPL from my speakers conveys none of the emotional aspect of my music so I prefer it more around 88-90 db, thereabouts. I want a visceral impact to the sound of my system and 83 db does not provide that. By this, I mean when I am I doing critical listening.
I participated in a San Francisco Audio Society listening comparison of the totl Coincidence speakers to Andrew Jones' $200 speakers, maybe Panasonic, I forget now. We initially did an A/B session between the two pairs of speakers at a modest listening level, maybe 75-80 db, and the gathered listeners were totally flummoxed as to which two pairs of speakers were playing. I personally could not figure out which pair was playing, try as I might. Well, as you can anticipate, once the volume was turned up, it was 100% clear which pair was which, plain as day.
My best wishes for those that feel they are getting the full measure of their sound of their speakers at 81-83 db, but in my mind, that volume level in no possible way can portray the palpable sense of music reproduction on either my Spatial Audio speakers or my new Cube Audio Jazzon speakers. Long term listening at 90db is an issue and am aware of that, and I don't listen to music continuously at 90 db, but I do fairly often for short periods of time, and it energizes me.
If I were to be satisfied listing to music at 81-83 db, there are lots of inexpensive speakers available that sound just fine. But with more volume, the better speakers begin to shine, which is why we pay the large sums of money for them.
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Counting down the days on Don and Lynn 300b debut 😁
I currently do my listening after 8 PM for a few hours and typically my listening sessions never exceed 75 db and I don't feel like I'm missing anything; excellent imaging, sound staging, low level detail, clarity and tight tuneful bass based upon the type of music I typically listen to.
Wig😎
Don Sachs Kootenay KT88 Tube Amp
Radu Tarta 4P1L Transformer Coupled DHT Tube Pre-Amp
Merason Dac 1
ProJect CD Box RS2 Transport
Liberty Audio X-VOX (PBN) Loudspeakers
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Wig,
Dandy system you have, for sure. You have nominal 4 ohm speakers and if the Kootenai drives them to your satisfaction, then the 300b Statement monos will drive them as well, with an astonishing clarity that will be simply stunning. Cheers.
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@ whitesix
I know it would be for sure but it'll have to be a dream for now but one day...My Kootenay is maxed out and had hoped for some upgrades but not much to do other than another brand of boutique capacitors.
Wig👍
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Understood. The Kootenai is a fantastic amp, as I know having one. Let your pocketbook be your guide, but to be honest, Don and Lynn's 300b monos are in a whole different realm of musical excellence. Maybe you can come hear them at the Seattle Audio show?
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@wig
I currently do my listening after 8 PM for a few hours and typically my listening sessions never exceed 75 db and I don't feel like I'm missing anything; excellent imaging, sound staging, low level detail, clarity and tight tuneful bass based upon the type of music I typically listen to
Yep! As we all can acknowledge this is purely an individual choice. My listening levels align with you, Don and Thom. @whitestix prefers a higher volume and I understand. Whatever results in more listening enjoyment, go for it.
Charles
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