John Curl's Blowtorch preamplifier part II

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Joachim, I did not know that you were friends with Peter Evans. He was nice enough to loan me one of his Vendetta phono preamps for almost 10 years, after the firestorm. I worked with MFA on occasion, and I LOVED that preamp. Wonderful sound! Beat my JC-80, that's for sure.
Moments that you describe is what I seek, not so much in my own listening system, these days, but when I can find them.
I once found that a certain direct disc recording in Oslo at Electrocompaniet in 1976 gave me this feeling. Before the firestorm, a 1959 performance of Harry Belafonte at Carnegie Hall sounded wonderful through my WATT-Puppies.
The closest I get today, is 'Kind of Blue'.
By the way, it is Emeryville, which for everyone else is near Oakland and Berkeley, but is close to the bay.
 
I would not say that we are actually friends but over a certain time we met quite often.
He ones owned a pair of my speakers too but he is changing all the time. Must be hard for him to decide what colour Ferarri is apropriate to drive today.
That this MFA preamp is not made any more is a pitty. If you like sound like that our taste must be very close at least in terms of sound. That beast could really throw a huge stage.
I remastered Belafonte at Carnegie Hall back in the early 90th. We cut on a Neumann and when i find a spare i make sure you get one. Must have been a terible experience that fire. I saw Berkeley after the fire with my wife. It must have been in 93 and it looked really bad. We here in Germany experience floods and things like that but not comparable what you experience in the states.
 
Yes, Peter is a very wealthy and difficult to please, audiophile. I helped put up a Rockport phono turntable, once at his place. Also, I listened to the Manger Loudspeakers there, which was 'interesting'. Haven't spoken to him in years, however.
We sometimes work with Scott Franklin on some of our most exotic projects, who used to work with Peter at MFA. Jack Bybee hired him, and is very impressed with his work.
 
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Yes, Scott has very interesting ideas, especialy with tubes but that is not my teritory.
I spoke the other day with Daniela Manger. She has success now with an active studio monitor. A lot of syncronising studios buy it becuse it has a very good speach resolution.
You know, our syncronising studios are very good they say. Every famous american actor has a "voice" here. Her father had a huge influence on me. He presented a speaker in the 70th that could reproduce a squarewave and started the discussion about "time coherence". His original Discus was the first speaker i heard with Levinson and Threshold equipment that could reproduce a voice 20 meters back in the soundscape if it was recorded that way. Yes, your work and Nelsons is in my ears since a long time.
 
I first met Herr Manger in 1975, at the London AES Convention. We had dinner at Guild Hall, together with Michael Gerzon and Dr. Craven. We wound up fast friends after this. He gave me a copy of his research and it was OBVIOUS that he had made a breakthrough. Say hello to Daniela for me too. I have talked with her on several occasions at CES. Herr Manger has a wonderful paper on microphone transient response that he gave at the Montreux AES in the mid 1980's. A must read.
 
John, i am leaving for ETF. Manger has, with over 75 years now invented a microphone.
Haun has build it and it is a SINGLE super small mic with 2 membranes stacked over each other that picks up a Stereo signal. This guy is amasing and he talked in glowing words about you too, so you made quite an impression on him. I say hello to Daniela. She will be happy about that. Best wishes too from Martina Schöner of Loricraft-Garrard. She drives me to France.
 
I've got about 4-6 'improvements' to loudspeaker drivers that I've been sitting on for about 10 years now. I'd love to be able to use them some day.

Sadly, I do not own the SYS-2722, I (company) leased it for a time, to do some tests. I thought I might do (if time remains) a few before-and-after measurements of that thing I showed you, John.
 
Mike, electronics is not an issue. Distortion is inherent to the phono/vinyl technology and is unavoidable.

Anyway, I like to listen to my set of LP's, especially those from the beginning of sixties, jazz recordings on Verve, RCA and Decca labels (regardless the unavoidable distortion :D)

My point is that the electronics will affect the presentation of vinyl's distortions. They can be presented in the proper perspective and less objectionable.
 
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My point is that the electronics will affect the presentation of vinyl's distortions. They can be presented in the proper perspective and less objectionable.

Mike, how's that? Should the electronics in some way 'modify' the signal to sort of 'un-distort' it? I don't quite understand what you are getting at.

jan didden
 
My point is that the electronics MUST transfer electric signal with as low influence as possible. The only exception, to me, is HF interference. So I would define the ideal amplifier not only as a wire with gain, but also as ideal low pass filter with cut-off somewhere at 200kHz.

Any other change in spectrum of the signal and of the response in time domain is IMO wrong, even if it 'pleases' the unique listener.

Regards,
 
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My point is that the electronics MUST transfer electric signal with as low influence as possible. The only exception, to me, is HF interference. So I would define the ideal amplifier not only as a wire with gain, but also as ideal low pass filter with cut-off somewhere at 200kHz.

Any other change in spectrum of the signal and of the response in time domain is IMO wrong, even if it 'pleases' the unique listener.

Regards,

Can't argue with that!

jan didden
 
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Can't argue with that! Except maybe that of course it's up to the 'unique' listener to modify his signal any way he pleases; we're not the audio police. Come to think of it, maybe also for the engineer/marketeer: he can modify the signal any way he pleases if he thinks it sells better. So, maybe, I CAN argue with that ;)

jan didden
 
One does not ADD distortion to Vinyl to make it sound at its best. One designs around the SUBTLE problems of Vinyl to keep the intrusions of the problems to a minimum. While I am often 'chided' for 'over-designing' phono reproduce stages, there are good reasons for my approach, starting with the JC-80, then to the Vendetta phono stage, and now to the Constellation phono stage. Interestingly enough, SY, in making his phono stage, does MUCH of what I have done, over the years. IF it did not IMPROVE phono performance, why don't we just go back to the Dyna MK 3 phono stage, and add an input transformer?
Now, in a nutshell, what have I changed over the decades?
For the first 10 years of my hi fi career, I used the Dyna MK 3 phono stage. I was fairly happy with it too, except that it was somewhat noisy, and seemed to have a 'mellow' or slightly 'mushy' sound, especially with MC cartridges.
When, in 1973, it became my turn to build a first class phono stage, I essentially copied the topology of the Dyna, and then made some improvements. These 'improvements' lowered the noise considerably, and I vastly improved the output current drive by about 20 times or more, because the Dyna was not really designed to drive its own RIAA caps properly, and this seemed a potential problem. Also, scaling the RIAA caps for lower overall noise made this necessary.
Not everyone, at the time, did this. For a time, perhaps 3 years, I thought that my job was done, so to speak, and went on to other projects. Then, 'cracks' started to appear in my design. More later.
 
The first 'crack' appeared when my colleague Sven Borja (sp) with Norwegion Radio, wrote me that while the Levinson JC-2 was good, he preferred the HK germanium phono preamp, that I think was called the Citation A. I was baffled, what could the Citation A do that the Levinson phono stage did not do? One possibility lay in the 2 stage character of the Citation phono stage. Maybe there was something to this? What, as an engineer, I could not understand. In fact, it seemed 'wrong' at the time. Another problem that came up with a review in 'Audio' magazine was that the RIAA was not as accurate as it could be. I had copied another RIAA network for the Levinson JC-2 and apparently it was slightly off from the start. This COULD be fixed, and later an update was made to the RIAA network to get it more accurate.
Now, my time with Levinson was finished, due to a royalty dispute, and I was hired by HK International to be a floating consultant for HK and sometimes JBL. This is when HK asked me to make a new, improved phono stage. They also told me that Elecrocompaniet had used a 2 stage design, (they were also colleagues of Sven B.) and that it sounded subjectively to HK, the right way to go. Also, I had heard the unit when I was in Oslo in 1976, and I knew they were on the right track, sonically.
Well, what the heck, why not? So I started to build my first 2 stage phono block, departing from Dyna, Marantz, and Mac, Audio Research, and even from my generally successful Levinson JC-2. More later.
 
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