Solid state phono preamp design philosophy

[PMA]

Interesting, Janasek was my competitor in solution of isolation amplifiers for power transients monitoring systems, some 11 years ago. Noise was not important, but immunity against fast CMV voltages was VERY important.

[john curl]

PMA, the examples were very primitive, nevertheless, at least 40 years behind. I hate to remind everyone, but we in the USA went to the moon in '69, and we had lots of heavy engineering behind it, some of which spilled out into the audio sector. When I look at such examples, it only reminds me as to how far ahead hi end design generally is over what people even know exists.

[Lumba Ogir]

Hi,
regarding MC, not just noise is a problem, the extremely small amount of energy involved as well. Just a very few devices have the ability to handle so weak signals satisfactorily, others cause (considerably) more losses and distortion. Parallelling does not help, means sonic degradation. However, such annoyances usually don`t make simulation data less fabulous.
For the orthodox minded only battery supply is acceptable.

[john curl]

This is not helpful.

[Lumba Ogir]

Mr. Curl,
did you mean my post, Sir?

[CBS240]

Hi

Just out of curiosity, would the KSK595H transistor work well as a phono input stage? I think there is a TO-92 version also. Good linearity with high input impeadance.

[john curl]

Yes, paralleling of parts does not lose information, and is often necessary for lowest noise. Power transfer is NOT the same as signal transfer. We have known how to do this since 1966, due to a paper in the IEE's 'Electronic Letters' found in research labs and in technical libraries at the time, and even today.

[john curl]

ksh device is OK for microphones, lousy for phono in general.

[PMA]

Originally posted by john curl
PMA, the examples were very primitive, nevertheless, at least 40 years behind.

I just opened the paper - you are right, of course. The designs were mainly for cheap PC based measuring cards, I know the story.

[CBS240]

Originally posted by john curl
ksh device is OK for microphones, lousy for phono in general.

It does state "capacitor microphone applications" in the data sheet. I assume it is has to do with the phono pickup being inductive? Or is this another point of insight chalked up to "experience"?