Hi. I have a swr sm500 and a goliath III cabinet. Lately the volume will drop for no reason. Then it will go back to normal. It might happen two or three times a song. I've been playing thru it for 8 years. I thought it might be the preamp fuse going bad? Does that make sense? I am playing a Modulus Q6 and have checked batteries, cables, etc. I don't think it happens using the DI on the back because FOH has never mentioned it but I hear it on stage. Thanks for any suggestions.
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swr sm500 power/volume drop
- Thread starter ultrabass6
- Start date
The volume drops a little bit in all four speakers at the same time instead of all the way off in one or two speakers so I was thinking the problem is in the amp. I'll double check the connections at the speakers. Thanks for the advise.
To me it seems that it might be the actual speaker jacks losing connection. If something is loose but not too loose it will stray away from wherever it's getting signal but still gets some signal that jumps through the air....This is unlikely though as you'd probably still get loud pops as it disconnects and reconnects fully. This would also be very likely to be very dangerous and if it's happened a few times without a fire or blowing the amp fully I seriously doubt this is the problem.
Are there any other symptoms? tone changes? pop? weird sound effects like fading or something like that?
Are there any other symptoms? tone changes? pop? weird sound effects like fading or something like that?
Two or three times in one song is too fast for a heat issue.
Two my knowledge, output transisters either work or they don't.
You got a bad connection somewhere. If it's not present at the DI it's probably not on any part of the circuit ahead of the master volume...take a hard look at everything on the output section and the speaker cab.
Make sure it's not at the DI with the DI post EQ, check your jacks, how dirty and scratchy are your pots? They can get bad enough to do that. Especially if it's one that doesn't get turned much.
Two my knowledge, output transisters either work or they don't.
You got a bad connection somewhere. If it's not present at the DI it's probably not on any part of the circuit ahead of the master volume...take a hard look at everything on the output section and the speaker cab.
Make sure it's not at the DI with the DI post EQ, check your jacks, how dirty and scratchy are your pots? They can get bad enough to do that. Especially if it's one that doesn't get turned much.
Thanks for the advise. No other symptoms like pops or crackles or tone change. It just drops volume. All of the sudden (no fade). Not a bunch of volume but noticable. I hope it just needs a good cleaning like you say. What happens when a preamp tube goes bad? Does it go out all at once or cause problems first? Could this have anything to do with it?
UPDATE: i took my amp in and of course they didn't find anything wrong. BUT...they cleaned the shat out of the input jacks and the problem seems fixed. Thank you all for your help!!
