New DSL40C Odd Thump and Volume Reduction:

[Inspector #20]

Had a brief issue with my new (unmolested stock) DSL40C.

I cleaned it with compressed air and made sure all tubes were seated before testing. When I started playing it, on the clean channel, I encountered this odd, percussive pop/thump when a note was plucked, followed by a light crackle (like crinkling paper) and a light volume reduction.

After a moment or two, the condition stopped.

All connections look good and are clean. Overdrive channel functions normally and the clean channel never gave trouble again after this single episode.

Think maybe speaker voice coil???

Thoughts???

 

[syscokid]

I cleaned it with compressed air...

Compressed air, from what source?

 

[Inspector #20]

Compressed air, from what source?

From a small compressor, carefully applied...

 

[67plexi]

 

[Inspector #20]

View attachment 28232

???????????

 

[67plexi]

All the JCM 800 Marshall's used cheap 16mm control pots no cleaning them replace them

The DSL has 11mm controls as in the photo posted. I have no idea if they are serviceable

 

[syscokid]

From a small compressor, carefully applied...

A way-out-there theory of mine is that maybe some moisture got into the amp because of the air compressor.

Did the amp's issue resurface?

 

[Inspector #20]

All the JCM 800 Marshall's used cheap 16mm control pots no cleaning them replace them

The DSL has 11mm controls as in the photo posted. I have no idea if they are serviceable

Ahhhh!!!!!!

Thanks for that tip. I did not know that...

 

[Inspector #20]

A way-out-there theory of mine is that maybe some moisture got into the amp because of the air compressor.

Did the amp's issue resurface?

Nope...nothing thus far!!!!!

 

[67plexi]

 

[Mitch Pearrow SJMP]

Nope...nothing thus far!!!!!

Maybe during the compressed air cleaning a itty bitty spider got lodged somewhere in the switch connections and the amp reacted to it. Because in 3 years that amp never once showed a problem of any sort at all, granted for the last 8 months it has only sat and looked pretty!
Cheers Mitch

 

[gball]

A way-out-there theory of mine is that maybe some moisture got into the amp because of the air compressor.

Did the amp's issue resurface?

Yeah, kind of almost sounds that way to me too from the description. Air compressors put an awful lot of moisture into the compressed air, so it's possible that some of that residual water was blown out.

 

[Mitch Pearrow SJMP]

Yeah, kind of almost sounds that way to me too from the description. Air compressors put an awful lot of moisture into the compressed air, so it's possible that some of that residual water was blown out.

Even with a filter moisture can still break through

 

[gball]

Even with a filter moisture can still break through

The filters are a joke, they take almost none of the moisture out of the compressed air, they are really for the oil. The only way to really get the moisture out is to use a dryer. That's why every compressor tank has a spit valve on it, so you don't rust it out from the inside.

I worked for a period of time for a major air compressor manufacturer, and we'd get rusted tanks back all the time because people didn't do any routine maintenance on them.

 

[Mitch Pearrow SJMP]

The filters are a joke, they take almost none of the moisture out of the compressed air, they are really for the oil. The only way to really get the moisture out is to use a dryer. That's why every compressor tank has a spit valve on it, so you don't rust it out from the inside.

I worked for a period of time for a major air compressor manufacturer, and we'd get rusted tanks back all the time because people didn't do any routine maintenance on them.

I had an emglo dual tank, 5hp Honda gas engine compressor tank rust out after 6 years of abuse, and the pump breakdown because of dirt!
Cheers Mitch

 

[Inspector #20]

It hasn't done it again....so, who knows???

 

[Mitch Pearrow SJMP]

It hasn't done it again....so, who knows???

You just need to run it through your rehearsal paces , and work the laziness out of it from sitting, it might have been a glitch of not being used, and she is mad at me but taking her frustration out on you my friend!

 

[Trident]

Dime it n let the rumble shake it out

 

[gball]

It hasn't done it again....so, who knows???

I'm going with some residual moisture from the compressed air. Theoretically it should be fine now I think.

 

[Mitch Pearrow SJMP]

Dime it n let the rumble shake it out

That is the best thing a Marshall can have done to it , you will know in minutes if something is shaky !!