Members bhuether Posted December 30, 2007 Members Share Posted December 30, 2007 Thanks to everyone who helped me figure out how to accomplish this. Here are details: Tubes: SED Winged C EL34 (2 matched pairs) Both pairs controlled by separate pots (1 pot for 2 tubes) Plate voltage: 503V Tube Pair 1:Max Neg on Pin 5: -78Bias adjustment: 32mA (corresponds to statis disspiation of about 16W)Pin 3 reading: 490VNote: 2nd tube in pair at 32.3mA Tube Pair 2:Max Neg on Pin 5: -78Bias adjustment: 31.5mAPin 3 reading: forgot to measure...Note: 2nd tube in pair at 32.7mA So the second pair wasn't quite as closely matched as first pair. But the avg result is a pretty close match. Not sure if I will try and push the tubes a little hotter. So far it is sounding pretty sweet. Incredible sweet clean tone plus raging gain. Just like I remember it when it was working! And I have 3 year old preamp tubes in it. Haven't even messed with those yet... Now if I could only get my Diezel Einstein working! later, brian Link to comment Share on other sites More sharing options...
Members Brick Posted December 30, 2007 Members Share Posted December 30, 2007 whats up with your einstein? Link to comment Share on other sites More sharing options...
Members bhuether Posted December 30, 2007 Author Members Share Posted December 30, 2007 I don't know, but here is an audio recording of me demonstrating the issues. Doesn't appear to be tube realted. www.guitar-dreams.com/misc/einstein_problems.mp3 If the link doesn't work, right click and hit save as. later, brian Link to comment Share on other sites More sharing options...
Members Dave Owens Posted December 30, 2007 Members Share Posted December 30, 2007 sounds like you better send it back to peter.. thats nasty.........( damn )... Link to comment Share on other sites More sharing options...
Members rockon1000 Posted December 30, 2007 Members Share Posted December 30, 2007 Glad you got figured out! Its nice doing it yourself. 65% idling dissapation? Sounds like a good number. No sense running hotter. Bob Link to comment Share on other sites More sharing options...
Members bhuether Posted December 30, 2007 Author Members Share Posted December 30, 2007 I have had the Koch running for 2 hours or so. Just measured the cathode current on the first tube pair to be 25 mA. Went down by 7... The 2nd pair was still at around 32mA. I adjusted the first pair back to around 32mA. Is this normal?? Paranoia starting to set in... thanks, brian Link to comment Share on other sites More sharing options...
Members Rich Posted December 30, 2007 Members Share Posted December 30, 2007 I have had the Koch running for 2 hours or so. Just measured the cathode current on the first tube pair to be 25 mA. Went down by 7... The 2nd pair was still at around 32mA. I adjusted the first pair back to around 32mA. Is this normal?? Paranoia starting to set in...thanks,brian Bias drift. It happens. I don't know how many matched sets of tubes I've bought only to have them drift apart no sooner than an hour or so after burn in. This is why I buy my tubes from lord valve. He burns them in then matches them up. Link to comment Share on other sites More sharing options...
Members rockon1000 Posted December 30, 2007 Members Share Posted December 30, 2007 I have had the Koch running for 2 hours or so. Just measured the cathode current on the first tube pair to be 25 mA. Went down by 7... The 2nd pair was still at around 32mA. I adjusted the first pair back to around 32mA. Is this normal?? Paranoia starting to set in...thanks,brian Did one tube drift or both? Link to comment Share on other sites More sharing options...
Members JaGi Posted December 30, 2007 Members Share Posted December 30, 2007 I don't know, but here is an audio recording of me demonstrating the issues. Doesn't appear to be tube realted. www.guitar-dreams.com/misc/einstein_problems.mp3 If the link doesn't work, right click and hit save as. later, brian Man that sounds screwed, is it not playable at all? Link to comment Share on other sites More sharing options...
Members R0B0 Posted December 30, 2007 Members Share Posted December 30, 2007 I don't know, but here is an audio recording of me demonstrating the issues. Doesn't appear to be tube realted. www.guitar-dreams.com/misc/einstein_problems.mp3 If the link doesn't work, right click and hit save as. later, brian Does this amp have a reverb? That first squeal sounds like a possible blown cap. If it has a reverb, check the reverb's transformer for damage. Link to comment Share on other sites More sharing options...
Members Duesentrieb Posted December 30, 2007 Members Share Posted December 30, 2007 Looks good Brian. - - - - - - - - - - - - - Change those three caps in the Einstein - with the Ruby's you've posted the link to. That should solve the issue. Link to comment Share on other sites More sharing options...
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