3SpeedChicken
Active member
I just picked up a new Roadster head, and talked the store into throwing in some matched Mesa EL34 tubes as part of the deal (I really like the RKII in EL34 mode...but didn't have quite enough $ for one).
No problem. They tossed in 2 reds and 2 grays (mesa match coding). Per the instructions, 2 different matched pairs should work fine if set in symmetrically (red, gray, gray, red).
Well, I did that and set the bias to EL34, then fired it up. Channels 3 and 4 sounded good, but channel one and two had serious issues. The overall volume was about 1/3 what it should have been, the sound wavered in and out, and there was some nasty unwanted gain going on.
I pulled the tubes out and switched them around, but had the same issues when I tried again (to test the tubes).
So I put the 6L6's back in, and all 4 channels sounded perfect again.
Does this sound like the bias switch isn't working correctly for the first 2 channels? Anybody else have this kind of thing happen?
No problem. They tossed in 2 reds and 2 grays (mesa match coding). Per the instructions, 2 different matched pairs should work fine if set in symmetrically (red, gray, gray, red).
Well, I did that and set the bias to EL34, then fired it up. Channels 3 and 4 sounded good, but channel one and two had serious issues. The overall volume was about 1/3 what it should have been, the sound wavered in and out, and there was some nasty unwanted gain going on.
I pulled the tubes out and switched them around, but had the same issues when I tried again (to test the tubes).
So I put the 6L6's back in, and all 4 channels sounded perfect again.
Does this sound like the bias switch isn't working correctly for the first 2 channels? Anybody else have this kind of thing happen?
