I built a homebrew - started off as a 1987, ended up adding the 2:1 layout, then a bunch of extra switches: bright cap, V1 gain, V2 gain, tone stack. NOS pre's, JJ output. All has been perfect for a couple years. Then, over the course of a week, the tone started to come and go - between normal and a tone sorta like when the tubes aren't hot yet, or when you power down and keep playing for those few seconds. I noticed it (or maybe it was coincidence) when I switched between the 1987 and 2204 sides. But now, it's all that thin bright weak tone, no more normal tone at all. I swapped each pre out 1x1, same deal. Had to be tubes right?? Tried swapping with another I know is good, nada. Tried all 3 inputs, switch settings, nothing made any difference.
Well after that didn't show anything, I took voltage readings and everything is pretty much normal, with the possible exception of V1, pins 1 and 3. Before, they were roughly 160v and .95v. Now, they read 195v and 1.75v. All else is normal as you would expect. Are these a clue? I'm stumped. Here are a few pix:
http://i912.photobucket.com/albums/ac32 ... CN0374.jpg" onclick="window.open(this.href);return false;
http://i912.photobucket.com/albums/ac32 ... CN0372.jpg" onclick="window.open(this.href);return false;
http://i912.photobucket.com/albums/ac32 ... CN0371.jpg" onclick="window.open(this.href);return false;
Any ideas?
Chris
![Bang Your Head Against A Wall :bang:](./images/smilies/mad.gif)