Here is an Accuphase AD-9 schematic

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Hello Folks,

I got the chance to take a look to a Accuphase AD-9 PCB ( Phono preamp module ) before usage. So I would like to see how the "High-End" boil thier water...
Attached you can find a schematic get from PCB wiring. A few values are missing ( Zehner diodes ) and power supply voltage but it may be interesting for you.
!Have in mind, that it is possible that I do mistakes!

Have a nice week,

best regards
Karsten
 

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Glad you asked. Here is a cheap integrated from a distinctly non audiophile company. Regulation is similar to the Accuphase. Part quality likely is not.
 

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Hello,

We should not forget, that the development of the AD-9 Phono module may several years ago. Today it is more wise to use an LT1115 or similar and a nice little Op-Amp for DC-servo.
But I often heard, that some "magic" is inside discrete setups. I never understand this personaly; all the thermal issues as well as the accurate selection of the FET/Transistors used for the differentional amplifier will lead you in lot of problems and.. is more expensive as an integrated version.

Regards
Karsten
 
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