Marshall DSL 100 overall volume issue

[Setneck]

Hi!

I suppose that was discussed quite many times but I couldn't find apropiate thread.

A friend of mine has a problem with his Marshall DSL100. It generally plays quiet - I mean, turned to 8-9 sounds on lead channel seems like being turned to 2-3. The clean channel can even be turned to 10 - and You can talk to each other freely standing right before the cab.

The amp wasn't modded in any way, everything inside is completely stock. It was inspected by two techs, who resoldered main points, cleaned the pots...a fresh set of tubes was installed... and no change for better.

Of course - everything else was also checked: we tried different speaker cables, guitars cables, cabs... everything.

A friend plays rehearsals turned to 8-9 and sometimes, for a second or two, the amp suddenly plays normally loud, but it goes back to low volume again immediately.

What is important - there are no changes of amp character or distortion character, or - if any - the change is very very small. It only plays much quieter than it used to play.

I also would like to know where to locate "bridge rectifier" in DSL. Which parts are this? I've read somewhere, that it might be one of the causes of volume loss, they say that it is quite common issue in DSL's.

Any thoughts would be much apreciated.

Regards, Andy

[guitarmike2107]

You had two techs look at it and its still not working right + you have paid for new valves when you probably didnt have too... ouch

Valve amps are dangerous to work on yourself if you have no previous experience, since you can't identify the rectifier and likely have no idea what it does I would suggest taking it to a Marshall authourised/experienced tech to have it looked at.

There could be a number of issues causing this, but if you dont have the skill and equipment to check it then it needs to go to a professional.

Mike

[Setneck]

No no, I don't want to mess with it by myself, as I am a musician, not a tech . I simply would like to help my friend, as the techs can't find the solution. If someone would give me a tip where to search the issue I'd pass it to the techs. I'm not gonna touch anything inside the amp . I wrote on forum because DSL's can be faulty and I simply hoped that someone had same issue before.

Authorised Marshall dealer is quite distant from my place, the repair will propably take long (precisely - waiting for repair to begin ) . Althought we don't exclude that option, we simply try to make it here, at ours place, as the issue would be an easy to repair.


Thanks for the input anyway.

[km6xz]

Was the amp and entire system inspected or just the DSL100? Any tech that does not identify a major gain reduction is not qualified to operate a TV let alone work in the circuits of an amplifier owned by someone else. Given that, I am going to guess it was not the tech's faults because they probably did not see the entire system and the problem was external to the amp.

Don't let any one replace anything unless they guarantee that that is the cause of the problem it was brought in for. I suspect that most tube and other parts replaced are needlessly changed solely due to the tech not knowing how to fix it than actually due to being defective.

[Pedro Vecino]

Are you using the 4/8 Ohms outputs?
If so, connect the 16 Ohms output to cabinet and test again.
If I remember correctly the signal step toward the 8/4 Ohms outputs is controlled by an internal contact (which may fail) in the 16 Ohms jack.
Regards

[sneakyybstrd]

Did you resolve this problem? Mine seems to be doing this now. I really have to crank it. My brother has the same amp and now mine is almost half the volume as his with the same settings and same tubes. I did a full swap. It's not the tubes. It use to just do intermittent volume drops within the first 20 mins of practice and unpluging my effects from the effects loop would restore volume. But now is permanent. Oh and both of them have 4/8/16 ohm ground mod.

[The Dude]

Try inserting a cable between the effects send and effects return. You could just have a bad switching jack. Also, if unplugging/plugging into the loop has temporarily restored operation, you could have cold/cracked solder on the jacks.

[Setneck]

Did you resolve this problem? Mine seems to be doing this now. I really have to crank it. My brother has the same amp and now mine is almost half the volume as his with the same settings and same tubes. I did a full swap. It's not the tubes. It use to just do intermittent volume drops within the first 20 mins of practice and unpluging my effects from the effects loop would restore volume. But now is permanent. Oh and both of them have 4/8/16 ohm ground mod.

Yes, the problem was fixed. The volume issu in my buddy's amp was caused by broken silver mica fizzy cap. After replacing it with ceramic one the problem has gone.

Regards, Andy

[sneakyybstrd]

Yes, the problem was fixed. The volume issu in my buddy's amp was caused by broken silver mica fizzy cap. After replacing it with ceramic one the problem has gone.

Regards, Andy

Any idea where that cap is located on the board?

[Setneck]

Any idea where that cap is located on the board?

It is C19 47pF cap on the poweramp board.

Regards, Andy