5150 volume cuts out

[8bit]

Looking for help with a 5150 sig model that I've owned since the late 90s. Lately having an intermittent issue where I completely lose volume. If I switch to other channel and back the volume usually comes back but not always. This really only happens when using the fx loop.

I've already tried cleaning the send and return jacks of the fx loop with contact cleaner, also just replaced power tubes. The amp had a cap job about 15 years ago.

Anyone else have this issue and/or know what the fix could be?

 

[likitlikeyoulikeit]

Looking for help with a 5150 sig model that I've owned since the late 90s. Lately having an intermittent issue where I completely lose volume. If I switch to other channel and back the volume usually comes back but not always. This really only happens when using the fx loop.

I've already tried cleaning the send and return jacks of the fx loop with contact cleaner, also just replaced power tubes. The amp had a cap job about 15 years ago.

Anyone else have this issue and/or know what the fix could be?

Maybe this ...seems like maybe a bad tube in the fx loop....maybe.

Peavey 5150 effects loop - Peavey Forum

 

[8bit]

Maybe this ...seems like maybe a bad tube in the fx loop....maybe.

Peavey 5150 effects loop - Peavey Forum

Yeah, I saw that thread. Wish OP would've said if that solved their issue or not.

 

[likitlikeyoulikeit]

Yeah, I saw that thread. Wish OP would've said if that solved their issue or not.

TBH, didn't read past the tube diagram...so it could help you troubleshoot the issue. Pull the amp from the chassis, if you feel comfortable and look for burnt out components or bad solder joints, since you said it had a recap ..just something to check....if isn't this, or a bad tube or transformer taking a shit ...I wouldn't be able to point you in the right direction.

 

[8bit]

TBH, didn't read past the tube diagram...so it could help you troubleshoot the issue. Pull the amp from the chassis, if you feel comfortable and look for burnt out components or bad solder joints, since you said it had a recap ..just something to check....if isn't this, or a bad tube or transformer taking a shit ...I wouldn't be able to point you in the right direction.

I'll probably start with replacing that tube. Basically no cost and if that doesn't fix it I'll pull the chassis I suppose.

 

[Snave]

This may not be the cause of your specific issue, but there's a known fault in the power tube heater cable of 5150s because Peavey used underrated Molex connectors. Might be worth checking.

PEAVEY 6505+ | PCBA Removal

How to detatch the main printed circuit board assembly (PCBA) from the Peavey 6505+ guitar amplifier chassis. Close-up photos of the damaged connector and circuit board that resulted in no sound from the speaker outputs.

www.bustedgear.com

 

[James Freeman]

A common problem with the early 5150 amps is the heater/filament traces and ribbon, which cause volume drops and eventually silence.

Well Freeman.... 6505's are like buses.... you wait for one... and two turn up!

thegearforum.com

 

[FuzzyAce]

And not just the 5150 from that era. I had to fix a Duel Two Twelve with the same issue. I ended up hardwiring the connections IIRC.

 

[joezlo]

It's either the FX Loop Preamp tube, or the heater filament issue.