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weird reverb problem!

10/3/2000 11:44 PM
weird reverb problem!
hi guys,  
Hope you can help me with this one.The amp is a 74 or 75 silverface twin reverb with master volume. the problem is a loud hum in the reverb,it is not feed back or oscillation it sounds almost like 60hz hum and it gets louder as I turn up the reverb control.Same hum with or without a guitar plugged into the amp.I've checked the obvious,tubes,reverb transformer, reverb pan everything seems ok.If I unplug the pan or switch off the reverb with the footswitch the hum all but disapears.The amp itself seems to hum a little louder than it should but with no change when I turn up the volume,it stays constant not like the reverb hum which increases as the reverb level is turned up.No the filter caps have not been changed butI can't see why they would only affect the reverb circuit.  
Any ideas???  

Randy Jamz You neglected to mention the Reverb... -- 10/4/2000 12:43 AM
Stan Cotey Do you have actual reverb signal wi... -- 10/4/2000 10:05 PM
Rick Erickson The power transformer will induce a... -- 10/5/2000 8:30 PM