amp sounds fuzzy - current circuit problem???

baltsen · #1 01-16-2013, 08:29 AM

Hi guys,

I have a little problem with my amp (ashdown abm 500 evo iii). Actually, I think its more a problem with the current circuit in our rehearsal room, but I'll come to that later. The problem in the first place is that the amp sounds really really fuzzy.

However, the DI-signal (pre-eq) sounds completely clean!... So I went to my local music store (with all my gear; ABM 410 and 115, effects pedals and bass) for several times and tried to show them the problem, but the amp always worked in the store.

After I tried out some other locations (my apartment, e.g.) I'm pretty sure that there must be a problem with the power supply in our rehearsal room. The problem is not entirely new. It was the same with my ashdown mag c210 combo... Funny thing is, that it only appears during wintertime. Do you guys have any ideas about my problem?

I don't know if this is relevant for the whole "current circuit thing", but I'm from Germany.

I hope my english was good enough to give you an impression of my problem.

Best regards!
Martin

RickenBoogie · #2 01-16-2013, 02:59 PM

Get an outlet tester, and see for yourself if the power is what it should be. If it is, are you sure it's not your spkrs?

will33 · #3 01-16-2013, 03:04 PM

It's possible there may be a problem with grounding, corroded connections, low voltage, etc. in your rehearsal room if that's the only place you can make the problem happen. Could also be radio interference or something there.

Best to get the electrical wiring checked out as that's potentially not safe.

Tchuss.

BassmanPaul · #4 01-16-2013, 05:25 PM

At your rehearsal place when you are getting the fuzz, try disconnecting one cabinet. Does it still fuzz? If it does then reconnect the first cabinet and disconnect the second. Again does it still fuzz?? If so it could be the amp or the supply. If one cabinet produces the fuzz and the other one does not then that cabinet is blown.

My gut feeling is that your 1x15 is the culprit. At the store, I suspect, you were not at the same volume level as at your rehearsal place.

RickenBoogie · #5 01-16-2013, 05:35 PM

(I was going to mention the 15, but passed. Thanks Paul.)

B-string · #6 01-16-2013, 05:46 PM

It also happened with the combo and only in the winter time. I would have the power company check the supply voltage.
Martin your English was very good.

ldervish · #7 01-16-2013, 06:33 PM

My friend's 112 was sounding like that. he checked and verified the battery and the cord. As a last resort before going shopping for a new amp, he spritzed each jack on the amp with contact cleaner, and ran a plug in and out a bunch of times right after spraying each one. Bingo. On his combo the signal chain runs through the headphone jack and external speaker jack and if they get dirty the output is degraded.

baltsen · #8 01-17-2013, 01:30 AM

Thank you guys for your replies! Yeah, the blown speaker was my first thought as well. But both work great, I checked them out with several amps at the music store. Even at high volume levels. Our music store has special rooms for playing bass, guitar, etc, so being too quiet was never a problem... Anyway, looks like I have to focus on the electrical problems of our rehearsal room... By the way, the guitar amp (marshall tsl 60) is not affected at all by this problem... I hate my guitarist for that!

...

Lowbrow · #9 01-17-2013, 06:48 AM

Turn on the amp, turn each knob all the way up and down and listen for a scratchy sound. Dirty pots can sound like a fuzzy amp or blown speakers. Just spray out the pots with non-silicone contact cleaner if this is the issue. Honestly, I once almost replaced all my speakers one by one until I discovered this was the issue.