Sounds really great. Thanks for sharing. A question, I had a fish with a Cantrell mod. The sounds for dirt seemed to really rely on the cantrell modded channel and the brown channel. The Bogner modded heads from my understanding were modded with his blue circuit board. It sounds like based off this description the preamp is kind of a big mix of all of these things? or am I totally mistaken here.
I believe you are on the correct path. There were “many” mods Bogner did with the small blue PCB with his initials on it “RB”. Not always the same circuit mod either. I have seen some that were small gray or silver PCB’s. Mark Cameron’s friend Jason found a 2204 in Bogner’s home town in Germany which was incomplete. Jason told me it took Mark about 3 years to get it where they wanted it.
Jerry used a few different amps on Dirt to include Dual Rectifier’s. Sometimes layering a cleaner tone as well just as Lynch & others.
For me the greatest tone is We Fie Young on Facelift. It is really raunchy with a kind of grind to it. I have been working in that direction as I have not heard it reproduced to date with just a guitar straight in but I’m close. Factor in any pedals that may have been used, how hot the mixing levels were etc…
Chasing tone can drive a guitarist crazy.
The go to Cantrell mod a.k.a. Snorkler, Fish & even the Hafler-Bogner Triple Giant use a lot of .047uf coupling & tone stack caps with variations on a traditional 1959 TMB & even a completely different variant to arrive where the builder desires. BRIAN at BFG also has completed a couple of these circuits that I am aware of.
I have been inside several variants from different builders. I will simply say it is my opinion that there is a lot more to the Facelift tone than a four stage, non cathode follower circuit using .047uf caps to reproduce what I hear. I feel the cords, double stops should bloom & lead lines sing. This requires a balance of saturation without too much compression which would likely answers why some guys use a variety of components & changes when building the same “mod”.
I for one have more core modifications which take up to 15 hours to complete. I then use Deca boxes to fine tune the circuit. Then I put about ten hours on an amp to settle the resistors & flow the caps before a final bias & approval.
I hope this addressed your questions.
Thank you for listening & posting.
David Hopkins