Conrad Johnson PV-9a VS PV-11

Have a PV-5 as a back-up preamp. It was my original preamp til I purchased a Joule Electra LA-150 Mk2. I sent the CJ back to the factory where they put in a new power supply and upgraded capacitors--huge diffference! No dull sound now, and very quiet with new tubes.

I found a modified PV-11 to sound better than the 9a in my system(replaced crappy black solen caps in the signal path with Audiocap Theta. After the mods, the PV-11 equaled the dynamics and openess of the 9a, but sounded a little sweeter in the mids (without sounding dull like the PV-5 does to me)

Thanks for the opinions.

At first I thought there was some resolution missing in the 9a. But it was more extended top and bottom ends, so it couldnt be that.

I realized after listening a couple of days that the 9a is just smoohter so at first listen you might think you are missing something.

The music is all there but smoother and more laid back. so I find myself leaning into the music more. It seems also that the soundstage is more accurate and the 9a is overall a more sophisticated sounding piece.
The extra bonus is that I can use my .6mv output Koetsu Black without a stepup or external phono stage no sweat. However my CDP which is 2.7mv output is a bit too much with the gain that this preamp has.

I ordered a pair of Rothwell attenuaters to solve that problem. What do you guys think of these?

Also can you tell me what tube combos you used with the 9a? By the way I have it paired up with a CJ MV-55.

Thanks in advance

Excellent summary, Francisco. I owned the PV-9a and listened to the PV-10 and PV-11 as they were introduced. My observations at the time exactly track with yours.
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I owned both many years ago. For me the PV11 can not be compared with the PV9a – the PV9a was a much more musical preamplifier, with a better sense of bloom, space and scale, much better dynamics. The PV9a was noisier than the PV11, but if properly matched was a fantastic buy - hifi is much more than signal to noise ratio! Do not match it with an high gain amp and high efficiency speakers. BTW, I used them with a MV125 and Sonus Faber Amator / Quad ESL63– fantastic systems.
Even technically , there is no doubt – the PV9a had a suspended chassis and much better coupling capacitors. The volume potentiometer was much better in the PV9a.

Regards
Francisco

Lot's of bloom and wrmth but still from era wehn CJ had lot's of noise as penalty.ZASince I woned lower end pre's (PV10) and MV50 amo I an anzed a how qiet they got durring 90's.If you can pony up for latter model I;d o for them.Righ now I need a pohonon stage but need outbopard adjustability.If not I'd save moeny and not get a Whes anget their now discontinued EV1.Art Seris or 17LS aren't chep but well worth the price IMHO.
Cheers
Chazz