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
I've accidently stumbled onto a need to update this thread. Bought some Clarity CAP MR's 0.22 630V with the intent of upgrading the Rel Thetas on the Prima Luna amp board... that didn't work out well when you had 1/2" to play with for cap width and the new caps are 1" in width. So I decided to use the 4 caps as bypass cap's for the 2uf Theta's in the CJ PV10A and so far its a resounding success. One of the reasons I kept flip-flopping between the PL pre section and the CJ was because while the CJ sounded "just right" in the mid range it was too polite in the treble, even had some signs of distortion. Whereas the PL sounds airy, clean in the highs but in the mid range details just don't pop out the way they do with the CJ. After add of the Clarity CAP MR's, that experience of details popping has extended into the treble, and top hat cymbal resolves sharply, no splat or polite clap. I'm really enjoying listening to small group jazz now, amazing the amount of subtle percussion details.
I've grown suspicious that the Rel Thetas are behind why female vocalists in the same octave range sound sibilant, a kind of "glare" that was there before but muted... now with the MR bypass caps that glare can't hide. One of the pains of doing CAP upgrades is that you are limited by space for what you can substitute and at 1.8/2uf there aren't a lot of good options at 1" diameter or less. I have some Auricap XO's on order as a first stab, workable alternate suggestions welcome(staying away from Obliggato as they mechanically ring). Will update in about 3 weeks after the XO's are in and have had some playing time.
The Auricap XO's didn't last 2 weeks , bland and uninteresting. I've also tried using Rel Teflon 0.22uf bypass caps for the Rel 2uf thetas but they sound less dynamic, less fluid on vocals compared to when the Clarity MR caps are in as bypass caps. And the glare I was complaining about in February seems to be resolving as I make source improvements.