Same principle applies to the 3 channel heads, as well as the 2 channel. You're replacing a 22K resistor with a 50K trimpot. Read the whole post through, and you'll find a picture with an arrow pointing to the resistor you need to replace.
Yes thank you, sorry I tought it was a 2 channel. Can't wait to do this!! I was first a bit scared when I saw the blown up tube...
AWESOME!
Thanks so much