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

I remember there was a guy by the name of Joe Bermudez involved in that company. The power supply design reminded me a bit of an Audible Illusions as well as some early C/J product. I fixed one about 10 years ago. Hasn't been back since.

Here's something from High-endaudio:

PRECISION FIDELITY C-7 (LATER MODELS)
I sold this model when my store opened back in 1981. This is a "Classic Preamplifier", with a design far ahead of not only its own time, but even up to today. In fact, our current audio market is begging for an updated version of the C-7.

The C-7 was essentially a high quality (tube) phono-stage with two volume controls, a couple of extra (passive) inputs and no line-stage. This is "the dream design" of today's audiophiles who have phono-centric systems, like me. (My own preamplifier, the Jadis JP-80, was heavily modified to copy the basic design of the C-7.)

It's been some time since I heard one of them, but I remember their sheer natural quality and the cleanness and quietness that is consistent with no line-stage. The people who bought them, if they could live with the low-gain, loved them. (I'd love to hear a modified version, with the best caps available today. I would love even more to hear an all-out modern version of this design.)

I remember that the original C-7 had some design problems that translated into sonic problems, so look for the "A" or "Revised" versions. (I can not provide the schematics to make these revisions.) The C-7 should be modified with better capacitors, just like all the other preamplifiers from this era. They also require a high quality step-up device for low-output moving coils.

Recent- One reader just purchased a C-7 based on the above advice. His take:

"...soundwise - Wow! Lumi is taking a long rest. This thing sounds a bit dark (like most passives in my system, probably the amp), but it is so dynamic, immediate, transparent, and not greasy or euphonic or juicy. I'd venture to say it is rather accurate. Of all medium priced preamps that I've tried, and I've had many, including many Bruce Moore designs, this one is by far the best sounding, with great MM phono. It beats Magus by a wide margin and phono is a lot quieter (uses two solid state regulators). Thanks for a great suggestion..."

Bottom Line- If I was on "a strict budget" for a preamplifier, and with the choice of ANY model ever made, the C-7 (modified) would be my first choice.

Hello, My name is Kavi Alexander and I own Water Lily Acoustics, a small record label. In the early 80s your company sold a few of your preamps and hybrid power amps to friends of mine at industry accommodation pricing. You may remember this...
Anyway, I have recently been gifted a Precision Fidelity C7 preamp, which I am enjoying very, very much!!! I must add that it is an outstanding design!
Could you kindly answer the following questions for me?
1) How can I tell if the unit I have has been upgraded to the "A" version?
2) Will the unit fun long interconnect cables, say 15 feet of very low capacitance.
3) Would it be possible to get a circuit diagram?

Please visit my site at: www.waterlilyacoustics.com
Should you see any titles you would like, I would be happy to send them your way...
It would be appreciated if you can respond to: waterlilyacoustics@yahoo.com

I thank you for your time and wish you the very best.
Kavi Alexander.

Hello, I am Kavi Alexander, an Audiogon member. I recently was given a Precision Fidelity C7 preamp as a gift. A web search for a circuit diagram for this unit lead me here.
May I kindly request a copy of same from you?
If so, please email it to waterlilyacoustics@yahoo.com

I would be glad to send you a CD of mine in return, thus please visit my site at: www.waterlilyacoustics.com and make your pick and let me know...

Thank you and wish you the very best.
KAVI.

I would like to comment on gsakakeeny's post concerning his claim to have "designed" the Precision Fidelity C7 preamp in 1977 when the company moved to Santa Rosa. I worked for them in San Francisco and Foster City in the late 70's and they didn't move to the business park in Santa Rosa until the Spring of 1980, if I remember correctly. Prior to that I was under the impression that Bruce Moore was the C7 designer, and I had one or more discussions with him that concerned the C7. I was , in fact, the "designer" of the C7a, which was a cluster f___ and turned out to be one of the factors in my exiting the High End Audio business.

Riding on the success of the C7, thanks to glowing reviews which caught our fledgling manufacturing firm quite off guard, Joe Bermudez, who was in charge of Domestic Sales, suggested that we come out with an "upgrade" using polystyrene capacitors instead of polypropylene (or was it the other way around?). We had confirmation of the availability of the new caps and had faceplates made with the new c7a designation, but at the last minute there was some screw up with getting the caps. Joe told me to ship the preamps anyway and we would somehow follow them up with the new caps (when they arrived) with instructions on how to swap them for the old ones. I really don't remember if they ever got to us (it's been almost 40 years...) but we started to get phone calls about how great the "new" modified preamp sounded from our dealers, citing, between gasps, that there was now "depth" and "air" and "transparency" and all the other buzzwords in use at the time. Not a single person complained that the "new" preamp sounded exactly the same as the "old" one, and the accolades about the improved C7 continued to pour in. There were times when Joe, John Fong (the owner and person in charge of International Sales), and I would sit around and read to each other out loud some of the astonishing praises about our C7 being "improved" merely by adding the letter "a" to the faceplate, and laughing hysterically.

Lastly, I hope Mr. Sakakeeny changed the design significantly on the JV1 pre-preamp before he stuck his initials on it - it was my design, as simple as it was...