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Old 15th Jun 2016, 6:11 pm   #5
barretter
Heptode
 
Join Date: Jan 2006
Location: Todmorden, West Yorkshire, UK.
Posts: 549
Default Re: Uher 4400 Report Monitor noise problem

Yes, it plays back fine in mono and stereo and you can't really hear much of the noise in the left channel until the music stops. The strange thing is that today I installed a couple of new drive belts and now the left meter plays along with the music while the right meter is stationary. Presumably I must have disturbed something but I don't know what. Both meters kick on switch-on and the left meter reacts as the hum/moan noise builds up momentarily in the left channel. The tape/source switch doesn't have any effect in playback. I presume it's meant to be used for comparison purposes in recording mode, which I haven't tried yet.
The noise in the left channel disappears when I press the record switch but I suppose that means the noise is in the amplifier circuit.
I attach a picture of the inside : where would the preamp circuit board be? Many thanks
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