T
Tom
I have a 6 channel Carver AV802x 135 w/channel amp. I have never had
any problems with this amp, but slowly a hum started being noticable
from one of the speakers. If I reached behind the amp and just
touched the input connector, the hum would go away for a day or two.
So I figured it was a cable problem or a loose connection on the RCA
input jack.
A couple of weeks ago I tore down my system and replaced the pre-amp
to amp cables and looked at the RCA jackes on the back of the Carver.
All of the RCA jacks mount to the 6 amp circuit boards and then screw
into the back panel. Well the screws were all loose on these mounting
points so I tightened them up and tested the channel that was
producing the hum. It went away. Good I tought, so I reinstalled the
whole system. The problem is that then, I had hum from two different
channels! So I tore down the whole system again and with no inputs to
the amp, I connected the speakers. These two channels still gace the
hum at this point, so I loosened the screws holding the RCA jacks to
the case and the hum was deminished but did not really stop. I
reconnected everything again and once again, the two channels show a
hum.
Obviously there is a grounding issue in the amp. The carver has two
large transformers that each feed 3 amps. Each amp has it's own power
supply (rectifiers, caps etc) but I did not notice that there was any
chassis ground.
DOes anyone have any suggestions on how to troubleshoot this? I do
have a scope and meters etc.
Thanks
any problems with this amp, but slowly a hum started being noticable
from one of the speakers. If I reached behind the amp and just
touched the input connector, the hum would go away for a day or two.
So I figured it was a cable problem or a loose connection on the RCA
input jack.
A couple of weeks ago I tore down my system and replaced the pre-amp
to amp cables and looked at the RCA jackes on the back of the Carver.
All of the RCA jacks mount to the 6 amp circuit boards and then screw
into the back panel. Well the screws were all loose on these mounting
points so I tightened them up and tested the channel that was
producing the hum. It went away. Good I tought, so I reinstalled the
whole system. The problem is that then, I had hum from two different
channels! So I tore down the whole system again and with no inputs to
the amp, I connected the speakers. These two channels still gace the
hum at this point, so I loosened the screws holding the RCA jacks to
the case and the hum was deminished but did not really stop. I
reconnected everything again and once again, the two channels show a
hum.
Obviously there is a grounding issue in the amp. The carver has two
large transformers that each feed 3 amps. Each amp has it's own power
supply (rectifiers, caps etc) but I did not notice that there was any
chassis ground.
DOes anyone have any suggestions on how to troubleshoot this? I do
have a scope and meters etc.
Thanks
