Volume Fluctuations on a Marshall DSL?

[Rich_T]

Evening all, hope you have had a nice sunny warm day like myself.

I'm looking for a bit of advice on my Marshall DSL 401 Combo. Recently, while playing through the amp, the volume has died to a whisper, for anything between 10 seconds and a minute. It comes back to full volume again no problem after a while.

What would be causing this? It seems to only be a problem during the really hot weather we are experiencing in the UK at the moment. However, that could just be coincidence.

All of the valves appear to be glowing normally.

Any insights would be much appreciated.

[LesPaulRules]

Re: Volume Fluctuations on a Marshall DSL?

I have heard a few others mention a problem like this using DSL combos.
Most common cause was a loose wire, a bad solder joint, or a bad trace on the pc board. Could also be a dirty jack (output, input or speaker jack).

You might want to clean the jacks first, then maybe a tube swap. If that doesn't help, a trip to your local amp guy might be in order.

I had an old Carvin amp many years ago that experienced the same symptoms you describe. It was a loose wire that looked ok, but was actually a bad solder joint.

[thunderlung]

Re: Volume Fluctuations on a Marshall DSL?

Welcome to a world of hurt(potentially). I own the same amp and started to have the same exact problems....eventually it just died(all tubes were good). Had it in the shop three times. worked for a bit and died again. Tech said the solder joints were absolute crap. "They must have done this on a Friday." Finally it just had to go back to Marshall and they sent me a new one. Haven't had a single problem since and it has been 2 years. There is tons of info. on the web of this exact thing happening to many 401 owners. They can run a little hot and maybe that contributes. A lot of guys wire a fan to the back to cool em' down a bit. My opinion.....you can't polish a turd. If they can't fix it efficiently at the shop...send it back. All of the work was under warranty on mine but it was just too far gone to fix. Good luck man. Hope yours isn't the lemon mine was.

[Fresno Bob]

Re: Volume Fluctuations on a Marshall DSL?

yeah, gotta check those solder connections. Maybe a resistor on the grounding?

[Imp]

Re: Volume Fluctuations on a Marshall DSL?

get it to a tech and avoid switching it on as much as possible-

it's a solder joint somewhere, when my one did this and failed it was a fat fat joint, and it caused a chain failure all the way back to the power tranny!

just tell the tech what the problem is, and say you've heard it's a solder joint problem.. it may not be, but DSL401s are notorius for it

tom

[muttonchopsrule]

Re: Volume Fluctuations on a Marshall DSL?

i've heard of there being problems with the 401's tubes overheating due to poor ventilation. i guess that sounds like it may be the case if this is only happening in hot environments? try putting a fan behind the amp to blow cooler air on the tubes....if that doesn't work, take it to a tech.

[greendy123]

Re: Volume Fluctuations on a Marshall DSL?

+1 on cleaning the jacks, this problem just happened to me recently.

[Imp]

Re: Volume Fluctuations on a Marshall DSL?

i've heard of there being problems with the 401's tubes overheating due to poor ventilation. i guess that sounds like it may be the case if this is only happening in hot environments? try putting a fan behind the amp to blow cooler air on the tubes....if that doesn't work, take it to a tech.

this is also an issue, but the bridge rectifier solder joints need inspecting, right away. i've found a page describing the problem as it happened on my amp -

http://www.piller.at/music/index.php?target=dsl201/index.html

the section on the bridge rectifier is worth a read dude

tom

[Rich_T]

Re: Volume Fluctuations on a Marshall DSL?

Cheers for the info dudes, im going to take it into the tech tomorrow,its still under warranty.