Peavey VTM 60 recapped. No more hum and weird "out of tune" sounds.

[War_in_D]

I picked up a Peavey VTM60 here a few weeks back at a local pawn shop. This thing was the definition of "rode hard and put away wet", but the price was right and I figured if nothing else it would be worth saving. When I got it home it had a really loud buzz, the output was low and was very static-y so I tried the usual cleaning all the pots, putting known good tubes in, etc. and nothing seemed to help. The mid knob had been broken off, so I found a replacement knob on line and replaced that this weekend. While I had the board out, I really gave the pots and jacks a good cleaning and plugged it in today.

So, the buzz is still there but the output was louder and when I hit a chord I was thinking "man, my guitar is REALLY out of tune!". Which I thought was odd because I just used it the other day and it was fine. Rolled the volume off and strummed it, sounds right to me so I put the tuner on it just to double check. Everything's good. Turn up the volume on the guitar and hit a chord... Sounds like it's WAY out of tune through the amp. And on top of that, it almost sounds like it's got a tremolo or phaser on it. I'll be the first to admit that I'm pretty much a tard when it comes to electronics, but is there anything inside of a tube amp from a capacitor, resistor, knob, etc. point of view that would make a tuned guitar sound grossly out of tune when you play it through an amp? I figure this thing probably needs a cap job, but would that cause it sound out of tune? This just isn't computing for me, and I can't wrap my head around why my guitar is in tune but then sounds out of tune through the amp.

 

[Jaguarillo]

Kinda sounds like the filter caps. When they're going bad you get 120 cycle hum along with your playing and it makes it sound out of tune. A lot of techs (Which I am not) recommend changing these every 10yrs. Plus if they blow up it could take a transformer with it.

 

[War_in_D]

Kinda sounds like the filter caps. When they're going bad you get 120 cycle hum along with your playing and it makes it sound out of tune. A lot of techs (Which I am not) recommend changing these every 10yrs. Plus if they blow up it could take a transformer with it.

Amp is probably pushing 30 years plus, and doesn't seem to have had a very easy life. Probably way past time for caps then if I had to guess.

 

[Jaguarillo]

Did you notice if the board was cracked from the broken mid knob or does it have flying leads from the pot?
Mike

 

[War_in_D]

Did you notice if the board was cracked from the broken mid knob or does it have flying leads from the pot?
Mike

I didn't notice any cracks. It's one of those pots that has legs that snap into the PCB and then the leads hang out the bottom and are soldered in. Looks like this.

 

[ccn]

Hope you cleaned it with the right stuff .

 

[War_in_D]

Hope you cleaned it with the right stuff .

Me too

 

[Rocker68]

Really mimics filter caps. Visually ok ? Anyone local to you to ESR meter the big ones to confirm ? Good amps.

 

[War_in_D]

Really mimics filter caps. Visually ok ? Anyone local to you to ESR meter the big ones to confirm ? Good amps.

I didn't see anything when I looked at them the first time, but just looked again and it looks like there is scorching on the end of a couple of them. I didn't see anything oozing out, or bulges, etc.

 

[Dan Gleesak]

Definitely change filter caps first.

 

[War_in_D]

I looked online to see if there were any ready to go cap kits for the VTM's and was only able to find one place online that sells a ready to go kit (amprepairparts.com). However, their website says they are currently closed due to "technical issues", whatever that means. Luckily, they listed what caps were in the kit so I just found everything on the Mouser website and ordered the "kit" from there. Was cheaper doing that anyway.

So it looks like I'm going to attempt my first recap job. Any tips, other than to make sure all the voltage has been bled off before diggin' in there?

 

[JTyson]

The last peavey board I saw was TIGHT as far as the solder paths (other side of the board)
I'd clip the old caps leads close as you can get to the cap and put heat sink pliers above the board and solder the new caps leads to the old ones unless you see any sign of a connection issue on the board. The pliers will hold everything in place while you solder it. Unless you have soldered components into boards before and are comfortable with doing it of course...

 

[JTyson]

I didn't see anything when I looked at them the first time, but just looked again and it looks like there is scorching on the end of a couple of them. I didn't see anything oozing out, or bulges, etc.

View attachment 243260

I zoomed that pic, and it looks like the lead to the second cap from the left is not even connected (??)
Maybe its the pic. Its not smoked as bad as the one next to it. Weird.. You'd think it would have blazed out. There is a hole where it used to be connected.

 

[Music&Chaos]

I didn't see anything when I looked at them the first time, but just looked again and it looks like there is scorching on the end of a couple of them. I didn't see anything oozing out, or bulges, etc.

View attachment 243260

I think someone else already mentioned but looks like a leg isn't even attached when zooming in. Probably some quick solder work and the amp will be good as new!

 

[War_in_D]

I think someone else already mentioned but looks like a leg isn't even attached when zooming in. Probably some quick solder work and the amp will be good as new!

It's definitely attached, I've pushed and prodded on the leg and it moves the entire cap. I wish it would have been that simple. LOL

I think that picture makes it look like there is a space between the leg and the cap.

 

[Music&Chaos]

I st

It's definitely attached, I've pushed and prodded on the leg and it moves the entire cap. I wish it would have been that simple. LOL

I think that picture makes it look like there is a space between the leg and the cap.

View attachment 244847

I still see some rough solder joints when zooming in. I'd resolder those fresh to see if it helps. I'd also go ahead and do the swap if you already have them for good measure. I had an odd amp issue that soldering resolved that was stumping techs. You never know! Hope it is something simple/easily fixable.

 

[Dave M]

If there's any question, then he should flip the board over and really check. Guessing and shotgunning is bullshit methodology.

 

[Music&Chaos]

If there's any question, then he should flip the board over and really check. Guessing and shotgunning is bullshit methodology.

No, I mean the joints themselves that are attaching the legs to the filters or to the board. You look for a shine or dullness with solder. It isn't just randomly hitting things. I agree, methodical troubleshooting is always best. If you visually see something off and you can touch it with solder in 5 minutes, could save a lot more time. Best option: Take it to an amp tech. BUT- Amp tech couldn't find my issue and it ended up being a weak solder joint. Something easily tested that could have saved me hours of time. You never know

 

[War_in_D]

Finally got around to recapping the VTM 60 this weekend, and it turned out great! No noise, and sounds like it should. The only problem I ran into was the teensy-tiny little cap on the power tube board. All the other boards were screwed in so I was able to take them out and remove the left over leg bits once I had snipped the cap out, but the power tube board was attached with rivets. So, instead of removing the board, clipping the old cap out and then removing the remaining leg from the underside.. I had no choice but to pull that one straight out through the top. Well, when I did that I lifted one of the solder tabs and some of the trace because the legs were bent under the board and grabbed them on the way out. Luckily, nothing broke and it all stayed together. When I put the new cap back in there it pushed everything back down and the solder locked it in. I was a bit nervous plugging it in for the first time, and did so without any tubes in it but thankfully nothing blew up!

I also fixed the power cord. The outer jacket had split right were it went into the amp and the inside wires were exposed. I had also spent some considerable time cleaning it up, and repainting all the corners, etc.. I wish I had taken a "before" picture of this thing. It was in pretty poor shape and literally looked like it had been rolled though a mud puddle.. The chassis was so dirty and dusty, you couldn't read the tube information on it. It was horrible.

 

[Music&Chaos]

Glad you got it all sorted! Thanks for the update. Rock on