Members Michael McGlenn Posted March 12, 2008 Members Share Posted March 12, 2008 One channel of my Mesa 50/50 poweramp is farting out the lows, and occasionally fluctuates in volume like 1db or so. Mids and highs still sing, but aren't as punchy as the other channel. I have a Quad of JJ 6L6's that are fairly new, less that 2 months old in there now. The preamp tubes were the stock Mesa 12AX7A Russians. I removed all of my 6L6's and put the old EHX 6L6's in and changed all of the 12AX7's also...same problem. Is it a filter cap thing? How do I test for what? Please help, Thanx Link to comment Share on other sites More sharing options...
Members Michael McGlenn Posted March 12, 2008 Author Members Share Posted March 12, 2008 Bump for answers :poke: Link to comment Share on other sites More sharing options...
Members knucklefux Posted March 12, 2008 Members Share Posted March 12, 2008 i'd have to look at the schem for a 50/50, but my assumption is that both sides share the power supply. if that is the case, filter caps are probably not the problem. does the 50/50 have a depth or presence control? if so, it may be one of those pots or something else in the NFB loop causing the trouble. you can pretty much rule out anything that both sides share since it's only one side. and since it's intermittent (at least, that's how i read it) it's probably not a component failure. have you switched the cabs too? it could be something other than the amp. the only way to single out one side is to use known good stuff on both sides. that's just a shotgun, off the top of my head idea. good luck. Link to comment Share on other sites More sharing options...
Members Michael McGlenn Posted March 12, 2008 Author Members Share Posted March 12, 2008 Thanks for the response. Yeah, I switched cabs and input signals. It seems to only happen on channel 1. This is the channel that runs my Earcandy cab and it shouldn't Fart out on 2 I looked around inside when I changed out the preamp tubes and didn't notice any leaking or bulging of the filter caps. From what you said...probably not. I will try the idea of the Presence control on 0 and see if it helps. Link to comment Share on other sites More sharing options...
Members HKSblade1 Posted March 12, 2008 Members Share Posted March 12, 2008 swap the tubes from side 1 to 2 and see if the problem moves to the other channel. Link to comment Share on other sites More sharing options...
Members Michael McGlenn Posted March 12, 2008 Author Members Share Posted March 12, 2008 Well, I did that first thing. No change. Then I swaped out all of the power tubes with my old set. No change. Then I replaced all of the preamp tubes. No change. Then I put the Quad of JJ's Back in. So, where do I put the 2 Aspirin tabs in? Ha Ha! Link to comment Share on other sites More sharing options...
Members Sex Panther Posted March 12, 2008 Members Share Posted March 12, 2008 So, where do I put the 2 Aspirin tabs in? Ha Ha!Do you REALLY want an answer to that? Link to comment Share on other sites More sharing options...
Members Michael McGlenn Posted March 13, 2008 Author Members Share Posted March 13, 2008 Do you REALLY want an answer to that? I knew I set myself up for that one...but I do think that my answer was funny Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.