4 months ago I bought C-5034-L PITTBULL 212 combo (assembled in April 2000), all original with factory tubes as well, still working. So I started re-tubing. I started repairing tube amps since ‘86 when I bought Vox AC30TB (cca 1963 with blue Celestions) and the amp had bad sound. I acquired Aspen Pitman book about tube amps with many schematics and repaired my Vox amp. Then friends started bringing me tube amps with problems and over the years my skills became refined so I started making modifications to satisfy customer wishes. I didn’t have schematics for many of the amps and I became skilled in tracing signal paths of many PCB tube designs. As a matter of habit I traced Pittbull amp without disassembling the boards.
Conclusion. DON’T TRY TO MOD PITTBULL AMP. IT’S PERFECT AS IS. ANY CHANGE WILL WORSEN THE SOUND. ALL COMPONENTS ARE CHOSEN FOR AMP TO SOUND THAT WAY, TO HAVE THAT CHARACTER. IF YOU DON’T LIKE IT BUY SOME OTHER AMP, DON’T TRY TO CHANGE IT. I MEAN EVERY COMPONENT MATTERS.
AND DON’T TRY TO CONTACT ME FOR A SCHEMATIC OF PITTBULL. IT’S THE ONLY AMP THAT I WON’T SHARE SCHEMATIC BECAUSE THE DESIGNER MADE PERFECT DESIGN WITH DISTINCT CHARACTER AND I HAVE ONLY RESPECT FOR HIM.
The best tube combination for me is; V1 chinese highgrade (I don’t have any mullards/philips’ left) V2 - EI NOS, V3 - RFT NOS, EF86 - VALVO NOS, inverter - chinese ( reasonable money spending) EL34 - RFT NOS, GZ34 - Your decision (I had some mullards left so… 
).
but reverb is thin and I must ask moderator is it o.k. to share one simple mod. just one capacitor and one resistor and reverb is fenderish
I could use the schematic, I’m working on one that has been modded and I want to Make it stock. Who ever modded it did a poor job and it’s blowing fuses.
Probably the problem is in power supply or power amp section. On c-5034-l the driver tube is one half of the ecc83 and the other half is standard cathodine phase inverter. That tube is close to output tubes. Phase inverter components must be matched. Please don’t do it unless You know what You are doing. As I can understand Fryette is willing to send schematic to proven service guys.
I don’t want to be expelled from forum because of something that is not allowed.
There are many pictures of the guts of VHT amps. They used the same boards for pittbull 45 and 50/12 amps, only few components are different and that is written on the component side. Footswitch (and some other stuff too) is tricky so it’s easy to make mistake. The designer is very smart guy so my advice is to find official service. The amp is worth it and because it’s very easy to make mistake caused by some clever design choices my advice is to contact them.
I’ll put reverb recovery mod one of these days