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Re: Rowe R88 continuous speaker noise
Posted: Tue Sep 06, 2016 10:54 am
by ami-man
Looking at your volume control plug, you have it the wrong way up connections 1 & 2 should be towards the amplifier handle.
REgards
Alan
Alan Hood
ami-man
UK
Re: Rowe R88 continuous speaker noise
Posted: Tue Sep 06, 2016 12:54 pm
by Rob-NYC
I just read Ron's remarks and this was exactly what puzzled me.
If speakers are disconnected any hum must be mechanical from something like a ballast.
As for the hum during play mode, without actually being there I am at a loss for explanation. This is one of the frustrating issues with these long distance attempts at troubleshooting.
I do suggest unplugging the fluorescent light and see what overall effect it has on both hum problems.
Rob
Re: Rowe R88 continuous speaker noise
Posted: Tue Sep 06, 2016 3:05 pm
by Koeppen
Ok one last video effort. Thanks for everyone's help on this, I thought a vid might help.
https://youtu.be/rH6hjPidal8
Re: Rowe R88 continuous speaker noise
Posted: Tue Sep 06, 2016 3:38 pm
by Ron Rich
Well--with the speakers un-plugged, I can't hear it. Did you un-plug the amp AC ?
If so, and you can still hear it--try un-plugging things till you don't --
Ron Rich
Re: Rowe R88 continuous speaker noise
Posted: Tue Sep 06, 2016 4:00 pm
by Rob-NYC
OK, that is 120 Hz hum -totally different. that is caused by a defective filter capacitor. It can also be caused by an excessive drain on the amp power supply, but since no fuses are blown and you have otherwise normal sound, I doubt that is the problem. After a few minutes of no drive, is the heatsink getting hot? Slight warmth is OK but not hot. Otherwise, this is routine capacitor failure.
If you don't have a scope, you should be able to find this by using the AC scale on your meter and having it "listen at each filter connection. With no drive you should just see pure DC -no AC component.
Rob