John Curl's Blowtorch preamplifier part II

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For jazz, try some Oscar Peterson.

One of my favorites is 'Salute to Bach'.

http://youtu.be/RPPQLzwCosI

Oscar was one of those rare geniuses. I could compare him to other pianists (Bill Evans and Teddy Wilson come to mind) but that would be unfair both to Oscar and to those I compared him to. He wasn't great because he was "like" some other player, he was just great.

A friend of mine grew up in Montreal at the same time as Oscar, he likes to say "We went to different high schools together". When he was in high school they would go to dances and socials where the teen-aged Oscar Peterson would play.

The great Norman Granz did a wonderful radio documentary about Oscar, and told the story how when Oscar was getting known in Montreal there was a rich American businessman who came to the club where he played every weekend, and told the manager that he wanted to meet the amazing piano player. The manager obliged between sets and introduced Oscar to the American, and Oscar said "Pleased to meet you" and stuck out his hand to shake that of the other "gentleman". The American looked shocked, and said "I wanted to meet you, but I will never shake hands with a n*****", and that was Oscar Peterson's introduction to the big leagues.
 
Oscar was one of those rare geniuses. I could compare him to other pianists (Bill Evans and Teddy Wilson come to mind) but that would be unfair both to Oscar and to those I compared him to. He wasn't great because he was "like" some other player, he was just great.

Those wouldn't be my first comparisons. :D I'd think more of Art Tatum.

My own personal favorite jazz pianist: Jaki Byard. The last time I saw him, it was in a tiny little after-hours club in Baltimore. The place was almost empty, which depressed me a bit, but he played his *** off. I chatted with him during a break, and went all cliche: "It's so wonderful to meet you, I have every album you ever recorded." He grinned and responded, "Oh, YOU'RE the guy!"
 
If I did my math right, a noise level of 1uV/rtHz means 141uVrms at the output of an amplifier with 20KHz cutoff. 1uV/rtHz seems relatively high for a power amp input stage, but for an 8R 100db/W speaker, the acoustic output seems to be -72db. Am I getting this right?
Ein values of around 6nV/rootHz to 100nV/rootHz seem to be the norm for power amplifiers.
1uV/rootHz is 1000nV/rootHz. That is far too noisy for most users.
About 40dB more noise than 10nV/rootHz which many low noise power amps can achieve.
 
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I would have to listen to more to form a judgement. That performance sounded a bit strained.

I gave away an Albert Ayler album back in the 90s to someone who was really excited to see it. I was banned from playing it in the house as it was basically 2 sides of strange squeaking noises. I rather liked it, but decided sending it to a home where it would be loved was the right thing to do.
 
1Vac is pretty close to the sensitivity of all power amplifiers.
The range of 500mVac to 2Vac probably covers >95% of all. That is a range of +-6dB on 1Vac.

What will determine what sensitivity YOU require, will be the maximum output levels of YOUR Sources.
Measure your Sources and find the lowest outputs. Design to meet that requirement.

Remember you can always add in a switchable 0dB, +6dB, +12dB gain stage to allow for low level signals.
That would allow you to go straight to a 2Vac sensitivity power amplifier and still accept low level sources down around the 500mVac maximum output level.

CDP and many other digital Sources are around the 2Vac to 2.2Vac level.
 
1Vac is pretty close to the sensitivity of all power amplifiers.
The range of 500mVac to 2Vac probably covers >95% of all. That is a range of +-6dB on 1Vac.
AndrewT, thanks for answering. This said, I was asking *precise* answers. All what you said is well know, and in a way, understated in my question. 500mv is not acceptable, even the old DYN normalisation says 0.775Veff minimum.
But i doubt any modern amplifier to be at this high sensitivity ?
I don't care for the sources, as it depends of the volume control position ;-)
 
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