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?
davide256

Showing 3 responses by hukkfinn

hukkfinn
28 posts
 
Hi Davide,
I would recommend the Bob Backert power supply mod for your PV10A. I have it in my PV12. I am now getting it put into my Art Audio 'Vinyl One' phono preamp. It's like getting a whole new amp. I believe the cost was $900.
I fully agree with your first 2 comments about the PV10A:
1) it's slow on transients
2) it's dynamically compressed.
With the Backert power supply, speed and dynamics will increase very noticeably. The compression will mostly vanish. When I heard my "new" PV12 for the first time, I went nuts. Bass punch was incredible, way better than any preamp I've ever heard, tubed or solid state.

I have no financial interest in Mr. Backert's mods business. I am, however, going to team up with Mr. Backert and try to get audio companies interested in using his power supply. So, even though I won't benefit directly if you get this mod done, if you publicize your opinion of the results, I could benefit *OR* I could suffer, depending on what your publicized opinion is. Everybody I know who has gotten it so far has loved it to death.
Mr. Backert's company, RHB SoundDezign, is at 215-355-0529.
-Hukkfinn
hukkfinn
28 posts
 
Just wanted to add that you would get Auricaps in your power supply with the Backert mod that I mentioned above.

Deleting the crappy electrolytics is one reason that it makes a preamp sound so incredible.

It's a bit over $700 for a CJ. The price varies with other kinds of preamps. Instead of the Auricaps, you can ask him to use V-Caps, and it's still only $900. But the Auricaps are already a HUGE upgrade compared to the stock electrolytics.

To my knowledge, there is no other power supply on earth that gives you teflon caps, like V-Caps. It just doesn't exist. I think this is why he is getting it patented.

Cheers,
Hukk
hukkfinn
28 posts
 
Hi Davide,
I noticed this part of your journey: "also replaced the stock electrolytics on power supply section with Nichicon fine gold caps but that didn't seem to cause a noticeable change"

Since the PV10A uses polypropylene, not electrolytics, for the power supply, I am wondering what is going on? The only 'lytic in the power supply is a single cap for the filament circuit, or the "heater" as they say.

Cheers,
Hukk
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