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View Full Version : Hum in my reverb... Help please

jeswin123
04-10-2007, 08:48 PM
I'm getting a hum when I turn on the reverb of my amp. I didn't notice it until I replaced the speaker(required rev tank removal). I seems to be related to the proximity of the power supplies for my effects board (One Spot and Yamaha stock 12VAC). Did I do something wrong?
jeswin123
04-11-2007, 08:03 AM
This problem is really bugging me.
joejazzguitar
04-16-2007, 06:52 AM
had the same problem with my Allen Old Flame....try re-orienting the reverb pan; if the RCA jacks on the pan are now facing the back of the amp, turn the pan around so that they face the FRONT of the amp.

I changed my pan, reverb leads and driver tube before I realized what my problem was...

joe
Rich M
04-16-2007, 09:54 AM
I had that problem in a Marshall 2205. Turns out the reverb tank wires were lying on the filament wires. Rerouting them did the trick.
GibsonSGgirl
04-16-2007, 12:28 PM
hmm wonder if that'll help my reverb problem on the DR...
rockon1
04-16-2007, 01:05 PM
I seems to be related to the proximity of the power supplies for my effects board (One Spot and Yamaha stock 12VAC). Did I do something wrong?


How close are the power supplies to the tank?
jeswin123
04-16-2007, 09:18 PM
Well, they are about 18 inches or so from the tank, but I didn't notice this problem before the amp surgery.
cadjack
04-17-2007, 01:51 PM
Sounds like the input/output leads are reversed. Does the hum get louder as you turn up the 'verb?
jeswin123
04-17-2007, 04:44 PM
Yes the hum does get louder when I turn up the verb.
rockon1
04-17-2007, 05:34 PM
Hows the reverb working -aside from the hum? If not well, perhaps the wire are backwards as cadjeck suggested. Also maybe a bad cable to the tank,poor connection or wire inside the tank broke off..... Also what happens if you move the ispot away from the tank?
phsyconoodler
04-17-2007, 06:07 PM
A poor ground at a number of points will cause reverb hum.One is the input jacks,then the output jack.And also the reverb cable itself.All of those need to have a solid ground connection to the chassis.When you removed the reverb tank you may have disturbed the cables and caused a bad ground connection.Take a jumper wire and hook it from the tank to the chassis and see if the hum stops.
It makes sense that what you disturbed is the source of the problem.Retrace your steps one at a time and you will likely find it.