2. amps-preamps
  3. 1297052009

Conrad Johnson PV-10A mod experiences?

Has anyone had experience performing a mod on the CJ PV-10A? I'm fond of this preamp, it has that wonderful tube openness and sweetness for harmonics. However over the past 6 months as I've delved into PC audio and DAC improvements, I've come to realize two things about it

1) its slow on transients
2) its dynamically compressed.

I'm using Mullard NOS tubes throughout as these seem wonderfully detailed with excellent base.

Since the preamp is built like an engineering prototype (overbuilt)my gut hunch is that some caps have aged (circa 1993)and need replacement, specifically the white CJ caps
and am thinking about replacing them first with Multicaps.

Wondering if anyone has experience trying to revitalize a PV 10A?
128x128davide256
6550c
393 posts
 
I was just reseaching the PV-10A a few days ago, and it really was made in three different version, but CJ did not give it a new name or MK# etc.

I was considering buying one, so it would be interesting to know what options there are. On the other hand, I wonder if the money would be better put on a new preamp that is close in price, like CJ's "Classic" preamp. I wonder what the sound improvement would be over a 25+/- year old preamp if any? Does "Classic" transulate to "same ol-same ol"?
davide256's avatar
davide256 OP
362 posts
 
I believe the 10A differences are all centered around the balance control knob which was eliminated in the last version. There is also a 10AL which had no phono section. The classic version front panel looks like a PV-10A but its tube complement is different and includes circuit components derived from the PV-12. As to sound on a classic, its a newer tube CJ... how can it not be be improved?
sabocat
3 posts
 
I've not listened to earlier models, but I really love my PV-15.
hifiman5's avatar
hifiman5
1,611 posts
 
I had my PV-12L extensively modified by RHB Dezigns located in Churchville, PA. Proprietor, Bob Backert designs his own proprietary circuits for the gear he modifies. He loves to work on cj gear! You can talk to him, discuss your sonic goals for your cj and he'll be able to tell you what he can do to get you there.

If you check other threads that discuss Bob's work you will find nothing but accolades! He is the real deal and a true gentleman to boot.

If modifications are in your future please consider giving Bob a call.
usblues
1,216 posts
 
I also have heard good things about RHB Designs.That being said I would be hesitant to mod a PV 10,YMMV,Bob
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