Marshall DSL 50 changing volume by itself???

[ShomerShabbos]

I got to the show and was setup for soundcheck by 7:30pm. My Marshall head stayed on the whole time, with the volume on 5. At about midnight it got louder. A lot louder. I didn't touch the volume knob.

Thoughts?

[tazzboy]

Sounds like a tube problem. Did you put the amp in Stand by when you weren't using it?

[JB6464]

Power tubes are wearing out , time for a new matched set.
If the preamp tubes start going , usually the gain starts falling off or they start ringing .

[strike771377]

I have a DSL 401 and I've had off and on issues with the gain knob pot "shorting" out. every once in awhile, you can barely touch it and it bypasses it or something and the volume jumps up. Might be worth checking at least...

[LPMojoGL]

It's got mojo.
It automatically know when to turn up during a gig.

[696]

Could be bad solder joints too. If tubes isnt sufficient, check soldering.

[ericb]

I have a few dozen amps and a few do that . I also have had a mixing board do that and also a few rack fx over the years. With 1 rackfx it was a solder joint, but with the rest, I'm pretty sure they're intermitten FX SEND/RETURN or INSERT Jacks. . I find if it's a 'serial/series' connection and it gets oxidized/dirty , or whatever, it affects things but only intermittenly . This is NOT a for sure answer by any means, as I literally have never figured out my dilemmas, but I'm pretty sure it's jack/connection related. It's typically not cables or tubes for me . Good luck and I'd love to hear more valid input on this thread


Eric

[Voodoo Amps]

Originally Posted by ShomerShabbos

I got to the show and was setup for soundcheck by 7:30pm. My Marshall head stayed on the whole time, with the volume on 5. At about midnight it got louder. A lot louder. I didn't touch the volume knob.

Thoughts?

We work on a great deal of these each month (ie: the JCM2000 TSL/DSL Series). Try bypassing your Fx-Loop, if the problem goes away when the loop is bypassed you most likely have some cracked solder connections. If the problem persists then you most likely have cracked solder connections on the Volume/Master Volumes controls. These are both fairly common on this series. I hope it helps you out and you get it resolved. If I can be of more help please feel free to post or email me at trace@voodooamps.com as I do not always get the email letting me know there is a reply here.

Many thanks and have a great day;
Trace

[83stratman]

YEP! This is the problem MANY times that no one usually thinks to trouble shoot.

Originally Posted by ericb

I have a few dozen amps and a few do that . I also have had a mixing board do that and also a few rack fx over the years. With 1 rackfx it was a solder joint, but with the rest, I'm pretty sure they're intermitten FX SEND/RETURN or INSERT Jacks. . I find if it's a 'serial/series' connection and it gets oxidized/dirty , or whatever, it affects things but only intermittenly . This is NOT a for sure answer by any means, as I literally have never figured out my dilemmas, but I'm pretty sure it's jack/connection related. It's typically not cables or tubes for me . Good luck and I'd love to hear more valid input on this thread


Eric

[stump]

I fixed a friend's DSL with this same problem. The effects loop was the culprit, poor solder joints. Seems to be a common issue with these amps.