DADA
Member
Would like a second opinion or confirmation that this idea will work.
The idea I read on another forum is to have a second Blue Channel.
To do so he lowered the 3 resistor values to matching that of the Blue Channel
Would putting a second resistor of 220K in parallel over R72 / R80 / R82 reduce it each to 110K?
Thank you all
Following is from another Forum.
The idea I read on another forum is to have a second Blue Channel.
To do so he lowered the 3 resistor values to matching that of the Blue Channel
Would putting a second resistor of 220K in parallel over R72 / R80 / R82 reduce it each to 110K?
Thank you all
Following is from another Forum.
So I had some free time last night and decided to tinker with the amp a little. I put some lower gain tubes in the channel 3 path. The gain was easier to control, but It really screwed with the tone. Amp felt thin and brittle and just didn't sustain like I was hoping so 12ax7's went back in.
After my initial disappointment, I decided to take the plunge and change out the plate resistors. I have modded my own amps for a decade and have built a few amps of my own, so I felt comfortable with making the changes. First note, This is probably one of the easiest amps I have ever worked on. Everything is labeled and is schematic correct. I wish Mesa and Peavey would get on board with this kind of clarity in design. Channel 3 has 3 plate resistors that are 220k (massive dirt/gain) so I decided to start there.
I changed out the first gain stage plate resistor first (R72 220k to 100k) It was a definite improvement but still insane amounts of gain. Was more touch responsive and cleaned up better but still light years more gain than channel 2, so on to the next 220k plate resistor.
R80 and R82 are both 220k plate resistors in channel 3's stages. I decided to change both at once and see where it put me. For me this is the ticket. Channel 3 ends up feeling a lot more like channel 2. There is more gain and a little more compression, but the gain is much more touch sensitive and you can clean up the channel if you want with just the volume knob now.
This mod probably is not for the metal head crew, but for rock & roll or classic VH, this is a huge difference. I think I will leave it for now.