Precision Fidelity C7/A: To modify or leave as is?

I recall the C7A-Revised being a fantastic sounding preamplifier. If you have merely a C7A, perhaps investigating what exactly the "revised" referred to would be an excellent starting point. Perhaps some generous "revised" owner out there would be willing to take a few detailed internal photographs for you to examine, as well as answer a few questions about the circuit changes in the "revised" version.

Cap upgrades are a crap shoot at best. Often, a designer will use seemingly pedestrian parts that are perfectly voiced into the circuit. Changes will render differences, but only your ears will emphatically tell you whether boutique parts are actually better. In my experience, you have a 50/50 shot of actually improving things without destroying the fundamental characteristics of the unit; presumably, it's these original characteristics which made the unit both worth keeping for an extended period, and worth attempting to improve. You takes your chances.

-Richard

Thanks for the response Richard. This piece is in fact the "C7/A Revised," as I recall printed on the circuit board. I think it is a monument to fine, fine engineering bar none but the perhaps a handful of other preamps. Thank you.

As I recall, your unit is a couple of decades old.
I had a Precision Fidelity, but a lesser model and it was a very decent sounding unit.
Simple design,dual volume or balance knobs and I think a couple of tubes, but a big open sound.
I should have kept it.
If I would have, considering it's age, I would at least have all the caps and resistors checked out and replace the ones that need to be replaced with better ones.
I would also try to find out where in the circuit that a cap upgrade would yield the best results.
This is where a good tech is invaluable if you can't do it yourself.

Pardon my initial comment that the Precision Fidelity C7/A Revised is "a monument to fine engineering bar none but perhaps few other preamps." Rather, a more appropriate and balanced statement would be that it is "a monument to the finest of engineering bar none given phonocentric systems."

Does anyone know if the C7A "modified" different than the "revised"? and, where the modified and revised versions silkscreened with "C7A Revised" on the back of them or was it just an internal change with the "C7" on the back?

thanks