DSL sound cutting out

[Mjojo51]

Dsl40c sound has cut out a couple times and had to turn off and on to reset. Think it may be a relay somewhere. . Anyone that's had this problem and narrowed it down please let me know.

 

[AlanH]

Dsl40c sound has cut out a couple times and had to turn off and on to reset. Think it may be a relay somewhere. . Anyone that's had this problem and narrowed it down please let me know.

I had a few cutting problems with mine in rehearsal situations and eventually put it down to vibrating tubes at higher volumes and some poor quality guitar and patch cables. I ended up buying some electrician's grommets from eBay for the other three preamp tubes and getting better leads and patch cables.

Rule these out first if you haven't already.

 

[Len]

Do they fade out, or cut out? Fade out might be bad tubes.

 

[Michael Roe]

JJ power tubes?

 

[Mitchell Pearrow]

Dsl40c sound has cut out a couple times and had to turn off and on to reset. Think it may be a relay somewhere. . Anyone that's had this problem and narrowed it down please let me know.

To the forum
I have not had that problem, but I am sure it will be addressed in your thread here

 

[ampmadscientist]

Dsl40c sound has cut out a couple times and had to turn off and on to reset. Think it may be a relay somewhere. . Anyone that's had this problem and narrowed it down please let me know.

1. Buy 1 new 12AX7 tube and swap the tubes out one at a time.
Retest each time you swap 1 with the new one.

2. Plug a guitar cable between send and return, then re-test. Do this with no effects connected.

These are 2 of the most common causes of cut-out in guitar amps.

3. It is probably not a bad power tube which makes an amp cut out completely.....and there is nothing wrong in general with JJ tubes either.

 

[Mjojo51]

Thanks for the responses but its not tubes or fx loop jack problems. Also when turning amp on occasionally if I don't hear the eternal relay switch click after hitting the on switch it does the same thing ( no sound ) and have turn amp off and on then it fine. Just wondering if anyone has had this issue and which relay in the circuit it would be that's possibly bad. Thanks

 

[Michael Roe]

3. It is probably not a bad power tube which makes an amp cut out completely.....and there is nothing wrong in general with JJ tubes either.

You are wrong on this or my amp tech lied to me! Not likely, read on...….My DSL head was cutting out and the problem was solved by replacing the arching JJ power tubes. The amp tech didn't replace them either, I did. He just identified the problem and I said, oh, well I have an extra set of Svetlana I will use them. Done! problem fixed.

 

[Mjojo51]

You are wrong on this or my amp tech lied to me! Not likely, read on...….My DSL head was cutting out and the problem was solved by replacing the arching JJ power tubes. The amp tech didn't replace them either, I did. He just identified the problem and I said, oh, well I have an extra set of Svetlana I will use them. Done! problem fixed.

sorry but your bad tube issue isn't what's causing my problem
Already replaced all tubes and problem existed before and after new and tested tubes were installed. Only acts up randomly like once a week so it hard to check results with anything suggested so far. I'll have to open it up and check for bad solder joints or connections somewhere. Beyond that its hard to find a intermittent component failure if that's the problem. Thanks

 

[Mjojo51]

Couldn't find any bad solder joints after probing and inspecting everything . Guess there's no actual Tech's out there that have come across this issue so I'll have to live with it till it cuts out permanently to be able to trace it down. Thanks to those offered suggestions.

 

[ampmadscientist]

You are wrong on this or my amp tech lied to me! Not likely, read on...….My DSL head was cutting out and the problem was solved by replacing the arching JJ power tubes. The amp tech didn't replace them either, I did. He just identified the problem and I said, oh, well I have an extra set of Svetlana I will use them. Done! problem fixed.

Arcing tubes could be caused by an impedance mismatch, or possibly shipping damage.

 

[scozz]

Plug a guitar cable between send and return, then re-test. Do this with no effects connected.

These are 2 of the most common causes of cut-out in guitar amps..

That’s very interesting @ampmadscientist, would you please explain the reason for connecting a cable between send and return in the effect loop? (No pedals involved)

 

[ampmadscientist]

Couldn't find any bad solder joints after probing and inspecting everything . Guess there's no actual Tech's out there that have come across this issue so I'll have to live with it till it cuts out permanently to be able to trace it down. Thanks to those offered suggestions.

No, don't play the amp, and continue troubleshooting.
It is a bad idea to play the amp right now.
Open the amp up and inspect the tube sockets.
Look for any parts that may have broken loose from the circuit board...

Possible issue bad speaker jack. broken solder connection on input jack.

 

[ampmadscientist]

That’s very interesting @ampmadscientist, would you please explain the reason for connecting a cable between send and return in the effect loop? (No pedals involved)

The effects jacks have switches internally.
The signal path of the amp goes through, and depends on these switch contacts.
When the switch contact gets oxidized or damaged the amp will stop working.
Connecting send to return with a cable bypasses these switch contacts.
If the amp works after bypassing, replace the effects loop jacks (cleaning is usually temporary but may cause the switches to work again).
It is always better to replace jacks than just cleaning on an old amp....for reliability anyway.

 

[scozz]

Thanks @ampmadscientist!

 

[Mjojo51]

Thanks for your Input I already tried jumping the loop and it doesn't solve problem. I've deal with Jack issues before and already checked out basic causes first. Its my only amp so I'm not going to stop using it. I've done a!l my amp repairs for many years and will eventually figure it out and If it dies before that and isn't repairable I'll just buy another one as needed. Thanks

 

[Ramo]

my DSL100hr cut out today while I was playing, first when I turn the amp on sound would not come i thought it need valves to warm up then I switched it off and on stb switch then it was fine, later on, I was playing and it cut out. this DSL seems to be pain in the ass it came back from repairs not long ago.

i was using a cheap guitar that has electronic problems could it be that?

 

[jacktheexcynic]

having a very similar problem. commenting to add that when mine cuts out (and it's getting worse, as in sooner after I turn it on), the channel switch also stops working (both pedal and amp face).

when I turn it off fully then turn it back on it is fine.

I will try other troubleshooting steps - the amp was used but in like new condition from GC with the tubes shipped in bubble wrap etc.

 

[Rokinroller]

My DSL40C does exact same . It is not a tube or FX loop jack issue . I went in and checked / re-tightened all the board grounding screws . Stayed good for couple weeks . Thought I got it . Nope still doing it . It cut out again the other night .
Then a couple nights ago we had flickering power due to storms and strong winds . I was playing the amp and when the power barely flickered , the amp did the thing again . It stays on but no sound . Turn the power switch off and right back on , and sound is back . Not speaker jack or connection . Its plugged to an external 16 ohm cab . Anyone have a GOOD CLUE ?
I'm thinking RELAY related .

 

[PelliX]

My DSL40C does exact same . It is not a tube or FX loop jack issue . I went in and checked / re-tightened all the board grounding screws . Stayed good for couple weeks . Thought I got it . Nope still doing it . It cut out again the other night .
Then a couple nights ago we had flickering power due to storms and strong winds . I was playing the amp and when the power barely flickered , the amp did the thing again . It stays on but no sound . Turn the power switch off and right back on , and sound is back . Not speaker jack or connection . Its plugged to an external 16 ohm cab . Anyone have a GOOD CLUE ?
I'm thinking RELAY related .

Yes, most likely. But the relay is probably not at fault, it's the supply from the microcontroller. And the clue is (often, no guarantee) that it's starved of voltage itself. Check the VCC on the IC and the relays when engaged. There's a cap inline with the VCC which may need replacing. If you need exact details search the forum here or I'll dig up the schematic tomorrow.