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


Hello:

We recently invested in a Precision Fidelity C7/A and I was thinking of upgrading some of the OEM capacitors. The original designer -- Bruce Moore -- apparently built the preamp. to sound as good as could be in stock configuration without having to modify anything, i.e. evincing the philosophy that an intelligent design should be simple and sound excellent as is.

Has anyone upgraded their Precision Fidelity with caps. such as V-Cap teflons or Auricaps and come away with dramatic differences in sonics, either for the better or worse?

Thank you.
somut
Thanks for responding: Yes, we plan on keeping the C7/A for the rest of our lives. At this stage, I simply do not know if $800.00 in V-Cap upgrades -- as excellent as they are supposed to be -- will be a move backward, contravening Mr. Moore's engineering philosophy on the C7/A that an impeccable, scientifically rigorous engineering concept should not need upgrading.
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."