Fender Twin Reverb channel 2 has no output

ibeatsars · 31st July 2010, 01:50 PM

I'm not sure if this is the right section to post this question in so forgive me if it's not. I have a show tonight with the band and what do you know? I went to fire up my 1972 twin reverb and channel two (the channel with reverb) has absolutely no sound output!

Channel 1 reacts as normal, works great - but channel 2 just died on me. I recently did a complete retube and it was sounding excellent.

Does anyone have any thoughts on what I could do to get it going? I'll be able to play the show, but it won't be the same without some nice vintage verb.

Thank you very much for your help!

Adam

807tubenut · 04:17 PM

check the connections on your reverb tank, if you have the old (but still working tubes?) try putting them back in and testing, do all the filament's glow on all the tubes?

Oh, and kinda silly... But is your reverb tank input plugged in correctly? (wire with thew red smudge going to the reverb input on the far right side)

mario13 · 1st August 2010, 04:47 PM

HI,
Check the second pre amp tube. Should be a 7025 I think. Check if its glowing. Switch it with the first tube if channel one dies its the tube. If not its the pre amp circuit involving the second tube and therefore channel 2.

hofnerbass · 8th November 2010, 05:34 AM

Check the 100k (I think) plate bias resistors with an ohmmeter. Do it with the amp unplugged, although you still need to be careful unless you know how to discharge the capacitors. Use the "one hand rule" when working with any tube amp.

I just replaced both resistors after finding them to be open on a '65 Twin Reverb reissue.

31st July 2010, 01:50 PM	#1
ibeatsars diyAudio Member Join Date: Nov 2005 Location: Burlington, VT	Fender Twin Reverb channel 2 has no output I'm not sure if this is the right section to post this question in so forgive me if it's not. I have a show tonight with the band and what do you know? I went to fire up my 1972 twin reverb and channel two (the channel with reverb) has absolutely no sound output! Channel 1 reacts as normal, works great - but channel 2 just died on me. I recently did a complete retube and it was sounding excellent. Does anyone have any thoughts on what I could do to get it going? I'll be able to play the show, but it won't be the same without some nice vintage verb. Thank you very much for your help! Adam

31st July 2010, 04:14 PM	#2
807tubenut diyAudio Member Join Date: Jun 2010 Location: SinCity	check the connections on your reverb tank, if you have the old (but still working tubes?) try putting them back in and testing, do all the filament's glow on all the tubes? Oh, and kinda silly... But is your reverb tank input plugged in correctly? (wire with thew red smudge going to the reverb input on the far right side) Last edited by 807tubenut; 31st July 2010 at 04:17 PM.

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1st August 2010, 04:47 PM	#3
mario13 diyAudio Member Join Date: Jul 2010	HI, Check the second pre amp tube. Should be a 7025 I think. Check if its glowing. Switch it with the first tube if channel one dies its the tube. If not its the pre amp circuit involving the second tube and therefore channel 2.

8th November 2010, 05:34 AM	#4
hofnerbass diyAudio Member Join Date: Nov 2010	Check the 100k (I think) plate bias resistors with an ohmmeter. Do it with the amp unplugged, although you still need to be careful unless you know how to discharge the capacitors. Use the "one hand rule" when working with any tube amp. I just replaced both resistors after finding them to be open on a '65 Twin Reverb reissue.

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