2. amps-preamps
  3. 1210354373

CJ PV-12 mods & upgrades by Bob & Gary Backert

I recently shipped my 15 year old CJ PV-12 preamp to Bob & Gary Backert of RHB Sound Design to have a few modifications and upgrades installed on the CJ.

My very first conversation I had with Bob was very enlighten to say the least. I informed Bob, I would be using the CJ PV-12 preamp for my phono stage only with the VTL 7.5 preamp. To make a long story short Bob & Gary completed their modifications on the line stage, phono stage, caps, gold/silver wire, power supply & IEC conversion.

Father & son went further to build a custom head amp stage, to increase the gain so I would have the ability to use a Dynavector 0.3mV. The technical construction completed by Gary is flawless and his soldering skills are impeccable. Gary’s workmanship is actually beautiful to look at. This is one heck of a father and son team.

Bob suggested that I listen to the CJ’s line stage before strictly using it as my phone stage only. So agreed to listen and it was magical.

If I could only use one word to describe the performance of my CJ PV-12 with RHB Sound Dezign’s modifications that word would be “Heavenly.”

The bass the highs the lows the midrange the vocals the sound stage the imaging have all vastly improved and it’s so much more transparent, liquid. and dynamic.

For the record I have not listen to the VTL since I setup the CJ, simply because the CJ is blowing it away. I know some of you may find this hard to believe but if I didn’t hear it for myself I would not believe it. The CJ’s dynamic linearity is stellar in all aspects. Well I guess I’ll be boxing up the VTL getting it ready for RHB Sound Dezign modifications and upgrades.

The CJ will be performing constantly for the next week or so to allow the V-Caps, wiring and all modifications to break-in nice & smooth for my musical enjoyment.
Bob & Gary, keep up the great work you are truly the man.
jmo
jmo OP
115 posts
 
After 72 hours of constant breaking in the CJ PV-12 with the RHB Sound Dezign mods & upgrades it's sounding better & better everyday. My VTL 7.5 preamp isn't getting any playing time he lost his starting position... I have him sitting on the end of the bench with a clipboard taking notes. It's basically like having a overpaid young superstar riding the pine watching the old seasoned pro deliver when the game is on the line.

Don't get me wrong I know when the VTL 7.5 goes to training camp in RHB Sound Dezign's lab Bob & Gary will send him home with a new and improved attitude, better shape, great legs and ready to take over the game again.

The RHB Sound Dezign modifications & upgrades are well worth the investment.
jmo OP
115 posts
 
With the setup of my new turntable this past Saturday I've been listening to vinyl all weekend long. I must admit the phono stage on the CJ PV-12 is so sweet with the mods & upgrades by Bob & Gary Backert and it's only going to get better once everything breaks in.

I went back and played some of my old classics such as:

1. John Coltrane & Johnny Hartman
2. Doug Carn, Infant Eyes
3. Miles Davis, Kind of Blue
4. Billy Cobham, Crosswinds
5. Norman Connors, Love From The Sun
6. Teruo Nakamura, Rising Sun
7. Return To Forever, Romantic Worrier
8. Wynton Marsallis, Hot House Flowers
9. Chick Corea, Friends

I had one hell of a weekend just sitting back and listening to very nice music and cleaning vinyl with the VPI Typhoon... Moments like these are priceless. :O)
lenkevy
15 posts
 
Thanks, JMO for passing along your experience. I just got off the phone with Bob. Nice guy. Here is where I am on this, help me out.

By the time I pay for an upgraded PV12, I can save money by buying a current model, PV 15L that is listed on AudiogoN. (I, by the way, don't use vinyl). So I asked Bob about the comparison. His reply was that they would upgrade even brand new models because they can offer (I paraphrase here) a better circuitry design and parts. Now, I am a newbie and not very smart when it comes to the technical side of audio, but it sounds like the reasoning is that "my design is better than Conrad Johnson's design - even if it is a brand new model." Now it certainly could be, and I may go through with the mods. But what about your thought process? Why did you choose to mod an old unit rather than going with CJ's new equipment using its proprietary designs? Did you have that much confidence in the mods? Again, I hope I have paraphased my understanding reasonably well.

Related topic: I think I'd like to have my preamp modify to use different power chords. Good or bad idea - any experience? (I use Von Schweikert VR2s, CJ MV60 SE amp and a Rega Saturn Cd player). Thanks for your thoughts.
jmo OP
115 posts
 
Hi Lenkevy,

The reason for my upgrades are I was planning to use the CJ PV-12 as my "phono stage only". I have a VTL 7.5 preamp and it doesn't have a phono stage. The VTL is a reference preamp and there was no need to purchase another preamp when I have two.

After Bob & Gary upgraded my CJ, that I paid $2500.00 for 15 years ago it sounds better then my $16,500.00 reference preamp. He's using better components then what the Mfg. use that's way the sound quality is better. Bob, takes what they have and makes it better with his custom designs.

Purchasing the current model will not sound as good as having your CJ PV-12 modified. The money I invested on mods & upgrades is well worth every dollar. Actually I think that some of the older products were built better anyway.

If you don't listen to vinyl just have them modify the line stage and power supply. You don't have to go crazy all at once. I'm just crazy like that. :O) After taking the ball to the goal line I didn't want to come out of the game so we stop I went for the TD.

The IEC upgrade is a must do for the use of different power cords. I highly recommend the Synergistic Research Tesla T2 power cord it's killer in preamps I use T2's with both preamps.
More to discover