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.
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.