Understood. Most are flat, unless they are more than just preamps. Tube preamps are usually more colored (distorted, but in a good way) than solid state. And, there are some very good clean preamps, which is more what I would have expected if accuracy were paramount. How about Massenburg 8400, or Millennia HV, etc.? Why a new tube preamp?
Was the design worth commercializing? You could have phono stages AND mic preamps!
At the time I thought so. It launched a company called Requisite Audio. It's called the Y7 mic preamp. It was basically just the Teletronix LA2A compressor circuit with the global feedback removed, change the 12ax7 to a 12ay7 and put a Jenesn mic pre transformer in the front end. It gets talked up in gearslutz sometimes. Today, looking back, it wasn't that wickedly great. I'd do a mic-preamp much differently today.
Maybe we should ask John if his phono preamp is designed to preserve signal integrity or is an effects box. He was quite offended when I recalled an old review that accused him of manipulating the RIAA to make his pre-amps have a unique sound.
I thought we are talking here of preserving something as it was intended not creating the content in the first place. There's nothing wrong with building phono pre-amps that modify the signal to produce something that is more in line with a certain listening groups preferences, but please call it like it is.
The would be the position of maximum purity. Not sure if all content providers are purists in that sense, or if they might be happy with some things that may help induce end users to enjoy and purchase more content without being too picky about what its called.
Also, not sure that content providers are always able to offer the listening experience they really want. Sometimes they are stuck with the best they can do, knowing in particular there are limitations with transducers at both ends of the process. If very small amounts of certain types of distortion can enhance the listening experience in a partially compensatory way, it might not be too bad a thing. Not aware of any perceptual research in that area, but have heard a nice apparent-effect that creates a subtle perception that sound is emanating from slightly in front of speakers (and heard others report the same perception). I believe the effect is due to some distortion, but haven't had an opportunity to characterize it with instrumentation.
Regarding calling things what they are, we have markets with supply and demand, and words matter. For example, if "effects box" is a derogatory term, probably not realistic to expect it to be used voluntarily. Maybe "patented enhancement technology" would be more acceptable to some.
In the case of JC, I get the impression he believes what he says.
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The problem is I have schematics of John's JC-80, there is nothing there at all that implies anything but an intent to preserve signal integrity exactly, no small amount of compression, no deliberate "slight" distortions, no carbon comp resistors, no inductors. There might have been a small error in RIAA values which John told me were corrected, I don't remember the story exactly. So please rationalize this with basing pre-amps on compressor topologies and using tubes for "beneficial" distortions. You guys are from different camps.
Got it. In Robert's case, it would seem that the tube mic preamp was intended to be colored in good way, as some professional preamps are. That should be okay because they are used for creating content.
The phono preamp is for reproduction, would be my understanding, but no reason why one company can't make products for both content creation and for content reproduction.
Regarding phono reproduction accuracy, when I looked at the Lounge website, I think it said the preamp is rated for .5% distortion. Don't know who measured it or how. But, a claim that specific about a product should probably be defensibly true by reasonable and customary industry standards.
Most of what else there is on the website appears to be from product reviews which seem mostly to say the product sounds very good. I didn't see what I would consider to be any false claims. Maybe you did, and if there are any, they should be corrected.
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Read the article, have the album. The article has an odd title given the content, it seems to me, which seems to be mostly about production. Regarding production, its been known for a long time that song, the arrangement, instrument timbres, etc., all have to be optimized for some kinds of music, especially music that is intended to sound loud and good at the same time.
And leaving many decisions until mix time is not new. If one has the wherewithal to record analog and digital and then pick and choose between them at mix time, that's not really what many would consider a whole new concept.
Also, sending "stems" for final mixing during mastering is not new, nor is adjusting mastering to compensate for different playback formats.
Mastering for perceptual encoders in particular tends to be a trial and error thing, because there is no way to predict exactly what the perceptual algorithms are going to decide is important to preserve, and what will be depreciated or eliminated.
Anyway, I am left unclear about what was changed about the way mastering works. If anything was changed it would seem rather incremental, rather than revolutionary.
Please, he was talking about an earlier product not what he sells on his site. I have seen no unreasonable claims at all. Just to note Jan and I have made some recordings with microphones as instruments, 100% global feedback, no compression or frequency response modifications at all, and were quite happy with the results. In my case it was a single acoustic guitar/vocalist and Jan won best in show with an audience of tube guys.
Sure, all depends on the music. Some music calls for clean, accurate sound. But if one wants the van Halen guitar tone, for example, some of that happened after what came out of the amplifier. And there are lots of pop vocals that are not recorded with the same low distortion that one would use for opera. It depends.
Yes of course, and I have publicly given much respects to those that create the great recordings. We are talking about phono pre-amps here (I thought) and playing LP's. I admit that stylus, cartridge, arm, and TT combos do determine in part the electrical signals that appear at the cartridge output but once they are electrical signals they can be further processed exactly. If that is pedestrian, that is your opinion not fact.
We have been talking about multiple things, and I think I was just responding to portions of your remarks. If we are segueing back to phono preamps, fine. Don't consider it pedestrian at all. But, I'm not sure that some purity factor represented by low the lowest possible measured distortion is at the top of what everybody wants from a reproduction system. And of course I don't mean they want is to them objectionable distortion.
Where I am having a problem, to frame it in terms of phono, is that I don't think it is necessarily clear that if you have two phono preamps one with .1% distortion and the other with .001%, that the latter one would necessarily sound better to everybody (depending on the exact distortion), or that it would necessarily be superior, but neither am I convinced that something with .1% distortion should be required to represent itself as an effects box, even if it is in some small way. Maybe we agree on this, I don't know. But if we do, then at what point would you draw the line? At what point it is morally appropriate to represent something as an effects box?
Where I am having a problem, to frame it in terms of phono, is that I don't think it is necessarily clear that if you have two phono preamps one with .1% distortion and the other with .001%, that the latter one would necessarily sound better to everybody (depending on the exact distortion), or that it would necessarily be superior, but neither am I convinced that something with .1% distortion should be required to represent itself as an effects box, even if it is in some small way. Maybe we agree on this, I don't know. But if we do, then at what point would you draw the line? At what point it is morally appropriate to represent something as an effects box?
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Having had JC look at a phono preamp I built he was a stickler for RIAA curve accuracy. But how could an audio reviewer be wrong? !!! 🙂 🙂
Thanks Simon for telling them like it is: I DO care strongly about RIAA accuracy, and always try to make it as accurate as possible. I use the INVERSE RIAA box designed jointly by Walt Jung and Stanley Lipshitz. It seems to be accurate, even today. Sometimes I am slightly embarrassed by the Parasound JC-3 phono stage, when the builders do not use accurate enough polystyrene caps, but not because I did not specify them on paper at least.
The RIAA specification is well enough documented, but 'out of band' operation is not, and can be argued about.
Some designers like to add an extra boost or roll-off at the frequency extremes. I do not do this. These additions would either roll off the bass at 20Hz, presumably to get rid of record warp generated signals, a practical solution for cheap records and players, or would extend the frequency response further by a boost at about 40-50KHz to make up for the limited boost possible when mastering the record on the recording lathe. Both additions I have found not useful.
For the last 40 years, my emphasis has been in making acceptable discrete phono stages with less and less loop feedback involved. It isn't a very 'practical' way to do it, but it does seem to sound better and better, the closer I achieve my goal.
So, deviating from the standard OP-AMP feedback circuit, I moved reluctantly to a two gain amp approach:
First with a simple differential pair of nchannel fets as the first stage with a cap across their respective drains to make up the 75us RIAA eq. This worked fairly well, and sounded better the Levinson JC-2 that was my reference at the time. (the JC-2 was not as accurate as I first thought, but its RIAA was designed by Richard Burwin, and I took it on faith, that it was as accurate as possible). I think this is where Scott got his info.
I was not the first to do this, Electrocompaniet and my colleague (who is still a formidable competitor) Bascom King advised me to do so earlier. I resisted, because it caused more stage complication and I thought maybe less listening quality, all else being equal.
I found that an open loop first stage really did sound better, and that then led to the JC-80 phono stage and finally to the Vendetta Research input stage that I still use today.
It is not 'effects' or distortion that I add to or want, it is just less feedback and better passive parts, yet still measuring adequately good enough to not be audible for that reason. About 0.03% for a phono stage is about the best I can do without any global feedback at all, and it should be OK, but I would get better results if at all possible. Still working on it.
The RIAA specification is well enough documented, but 'out of band' operation is not, and can be argued about.
Some designers like to add an extra boost or roll-off at the frequency extremes. I do not do this. These additions would either roll off the bass at 20Hz, presumably to get rid of record warp generated signals, a practical solution for cheap records and players, or would extend the frequency response further by a boost at about 40-50KHz to make up for the limited boost possible when mastering the record on the recording lathe. Both additions I have found not useful.
For the last 40 years, my emphasis has been in making acceptable discrete phono stages with less and less loop feedback involved. It isn't a very 'practical' way to do it, but it does seem to sound better and better, the closer I achieve my goal.
So, deviating from the standard OP-AMP feedback circuit, I moved reluctantly to a two gain amp approach:
First with a simple differential pair of nchannel fets as the first stage with a cap across their respective drains to make up the 75us RIAA eq. This worked fairly well, and sounded better the Levinson JC-2 that was my reference at the time. (the JC-2 was not as accurate as I first thought, but its RIAA was designed by Richard Burwin, and I took it on faith, that it was as accurate as possible). I think this is where Scott got his info.
I was not the first to do this, Electrocompaniet and my colleague (who is still a formidable competitor) Bascom King advised me to do so earlier. I resisted, because it caused more stage complication and I thought maybe less listening quality, all else being equal.
I found that an open loop first stage really did sound better, and that then led to the JC-80 phono stage and finally to the Vendetta Research input stage that I still use today.
It is not 'effects' or distortion that I add to or want, it is just less feedback and better passive parts, yet still measuring adequately good enough to not be audible for that reason. About 0.03% for a phono stage is about the best I can do without any global feedback at all, and it should be OK, but I would get better results if at all possible. Still working on it.
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The tube mic preamp I built back then was in the mid 90's. Remember, at that time all the signal processors/preamps in 99.999% of recording studios had to push through 44.1/48khz at 16 bit. That is largely the reason of the explosion of tube preamps at the time.
As for the 0.15% THD of the LCRMKIII, I measured it on an Audio Precision system 1 and an HP (can't remember what model). Both of these units were in a little lab in the back of Wes Dooley's AEA company. I think the actual number was 0.12% THD and I just rounded it up to 0.15%.
The current THD of the LCRMKIII is likely different now because I never stop tweaking the circuit. All I know is the returns because of sound have plummeted to near nothing. And THAT'S what matters. 🙂
As for the 0.15% THD of the LCRMKIII, I measured it on an Audio Precision system 1 and an HP (can't remember what model). Both of these units were in a little lab in the back of Wes Dooley's AEA company. I think the actual number was 0.12% THD and I just rounded it up to 0.15%.
The current THD of the LCRMKIII is likely different now because I never stop tweaking the circuit. All I know is the returns because of sound have plummeted to near nothing. And THAT'S what matters. 🙂
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