Apt-Holman pre-amp

a few years ago I used to upgrade the holman preamps.

They are old enough now that a full recap would be a good choice.
There are two short falls with the Holman pre amp.

1. a tiny power supply transformer
2. the TL072 texas instruments op amps.

Both can easily be corrected. Tons of choices out there now for dual op-amps. Same with transformers. I would normally leave the original in place and bring in the secondary wiring from the new transformer into the unit.
The apt pre also uses quite a few electrolytic caps to couple the stages together. These should all be bypassed with a film and foil cap.

And if you really want to go wild, you can Vishay the whole signal path resistors with the metal foil types.

best

 

Well, my favorite electronics is a Kinergetics KPA-1 pre-amp and KBA-75 amp. The Apt Holman pre-amp and two Apt amplifiers (set to mono-block) are also in my collection. The Apt pre-amp has almost almost as many phono adjustments as my Dolan PM1. The two amps' combined weight is less than the KBA-75 (75 Wpc full class A), versus 200 Wpc for each mono-lock Apt. There are both well built and while not sounding the same, are my two best set-ups now. Both better than Mc C-27 and MC-2100, Harman-Kardon Citation 17s and 16As, and Parasound HCA-2200ii.