Grateful Dead Music Forum

A place to talk about the music of the Grateful Dead 

Chat about Equipment Info
 #77808  by JonnyBoy
 Tue Apr 13, 2010 2:22 pm
The way I said that wasn't clear. It is on the far side of pin 6. I have noticed in the circuit of the caps and resistors, on the negative sides you can preamp tap at about 6 points, each having a different volume and hiss level. This is the best or clearest. it has QTY 4 -12AX7A and Qty 2-12AT7 but they give no reference to what it drives. An amp guy here thinks its the tube, it didn't work as the combo W/ tubes in, this time either.
Tube1 2 3 4 Tube1 2 3 4 5 6
6l6 6l6 6l6 6l6 12AT7 12AX7 12AX7 12AT7 12AX7 12AX7 looking at amp from the back
 #77811  by waldo041
 Tue Apr 13, 2010 3:06 pm
you still don't want the leg going to the tube, you should have the leg that is tied to the other side going to the 220k resistor. if i understand you you are going straight out from pin 6 of that preamp tube.

6l6 6l6 6l6 6l6 12AT7 12AX7 12AX7 12AT7 12AX7 12AX7

change the one in bold!

 #77821  by JonnyBoy
 Tue Apr 13, 2010 4:27 pm
Thanks Waldo, again when I said far side of pin six I meant the other side of the cap. the negative side. I can't believe I explained it again and still wrote it like you saw it. I have been that way all day. I had to explain my reverb four times too on another post. old Resin on the inner skull.
 #77823  by JonnyBoy
 Tue Apr 13, 2010 4:37 pm
How is it that my vibrato works as a preamp tap without power tubes? would that explain why the reverb doesn't, maybe? I think the reverb will work, since it won't work as a combo either. It did when I got it a month ago.

Edit: transformer failed.