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
Hi there,
You will find the cheapest Multicaps are far quicker and more resolving than the Solens. I would suggest you try these instead. Search on this site for Carey caps for others experiences. Good luck.
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
I've replaced the phono output caps as planned with the Solens. But in the mean time i've also upgraded my DAC. So once again the PV10A is doing some things well (tonal colors) but direct to amp from DAC is superior for fine detail and low bass. At this point I'm 90% certain im going to buy a Prima Luna product, either the prologue premium integrated or the Dialogue 2. Might be a sacrifice for bass wattage authority but the listen I had with just a Prologue 5 showed me that bass tonal color and weight is bleached in my current Pv10A/DH200 amplification.
After weighing pro's and con's I decided to go with the Prologue Premium integrated and bought separately cryo treated Genalux KT-88's (the EL34's just didn't cut it). The PV10A beats the Prologue for pre when feed thru the home theater inputs... more air, detail and extension into the top and bottom range of the audio spectrum. I'll probably tinker with upgraded components in the Prima Luna pre section later this year but in the meantime I've got 0.01uf bypass Vcap replacements on order to replace the Solens I installed in the CJ pre mains section... will check back in with a report in 60 days after the obligatory 100-200 break in hrs pass. Love the amp section for the prologue, no lack of power or base performance issues with the Magnepan 1.7's
I hadn't expected immediate improvement using the VCaps, noe the less I got one. While theres still a long break in time ahead, Im finding on every piece that has percussive bass there is much deeper bass. Bass drum is now a thunderous joy to listen to versus a polite whack.