Members Sandman31774 Posted January 6, 2008 Members Share Posted January 6, 2008 I switched my Peavey JSX to standy..i heard a loud pop ....i plugged my guitar back in and switched back to play mode and nothing...no sound...amp powers up fine...i have a G major in effects loop...i noticed no signal is being received to it..so i'm thinking bad preamp tube? your thoughts appreciated Link to comment Share on other sites More sharing options...
Members Sandman31774 Posted January 6, 2008 Author Members Share Posted January 6, 2008 all 4 power tubes glow nicely...all 3 preamp tubes glow as they should....however the driver 12ax7 for the poweramp section does not glow...could that be the culprit as to why there is no sound on any channel? i've made sure all cables are plugged in as should be and it's nothing to do with the guitars output jack, cable or anything ....it is the amp....the fuse has continuity (checked with multimeter)....anybody else have suggestions? Link to comment Share on other sites More sharing options...
Members Mavesicles Posted January 6, 2008 Members Share Posted January 6, 2008 You've got nothing to lose with replacing pre amp tube that does not glow. Link to comment Share on other sites More sharing options...
Members Sandman31774 Posted January 6, 2008 Author Members Share Posted January 6, 2008 You've got nothing to lose with replacing pre amp tube that does not glow. well it's the 12ax7 in the power stage....but i figure it should glow ....i'll have to go find me a tube tomorrow at the store and see if i can correct this issue Link to comment Share on other sites More sharing options...
Members alfonzoblues Posted January 7, 2008 Members Share Posted January 7, 2008 Turn your amp on and turn it up, then lightly tap the tube with a pencil.The tube that make the most noise or none at all should be replaced. Link to comment Share on other sites More sharing options...
Members HKSblade1 Posted January 7, 2008 Members Share Posted January 7, 2008 thats probably the PI (phase inverter) tube for the power amp tubes. If its gone, nada Link to comment Share on other sites More sharing options...
Members Sandman31774 Posted January 7, 2008 Author Members Share Posted January 7, 2008 thats probably the PI (phase inverter) tube for the power amp tubes. If its gone, nada yeah it's the phase invert tube....it doesn't glow...so it's probably the bad culprit...so if it's bad i'll get no sound from the amp at all right? because i have t urned on amp and tapped all tubes and no sound from anything...I'll go buy another 12ax7 tomorrow and check things out Link to comment Share on other sites More sharing options...
Members Chrisjd Posted January 7, 2008 Members Share Posted January 7, 2008 thats probably the PI (phase inverter) tube for the power amp tubes. If its gone, nada Thats what I was going to say. damn things can just pop without any warning or known cause. good luck J. Link to comment Share on other sites More sharing options...
Members Sandman31774 Posted January 7, 2008 Author Members Share Posted January 7, 2008 Thats what I was going to say. damn things can just pop without any warning or known cause.good luck J. thanks Chris,i'll buy a tube tomorrow and replace it...probably buy several tubes and keep a few spares for such events Link to comment Share on other sites More sharing options...
Members alfonzoblues Posted January 7, 2008 Members Share Posted January 7, 2008 Gotta love tube amps. Link to comment Share on other sites More sharing options...
Members rushtallica Posted January 7, 2008 Members Share Posted January 7, 2008 Good luck; I hope that's the culprit. Link to comment Share on other sites More sharing options...
Members rockon1000 Posted January 7, 2008 Members Share Posted January 7, 2008 If its a Sovtek 12AX7 LPS they dont glow "visibly" The heater is hidden inside the plates. If its not the PI you may have blown a fuse. If thats the case its usually from a faulty power tube. Bob Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.