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Old 23rd January 2013, 08:07 PM   #31
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No indication on the type-label on the back side of the amp?
Power consumption?
Is the original power-line fuse present or labelled?
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Old 23rd January 2013, 09:18 PM   #32
JMFahey is offline JMFahey  Argentina
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I doubt whether you actually have a problem.
The proper place for a BGW750 (I've had a lot of them, still warmly remembered) is in a rack, at either far end of a stage, behind a mountain of PA speakers.
Buzz ... !!!! What buzz ???
Are you speaking to ME? SPEAK LOUDER !! CAN'T HEAR YOU !!!!
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Old 23rd January 2013, 09:38 PM   #33
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Quote:
Originally Posted by TANDBERGEREN View Post
No indication on the type-label on the back side of the amp?
Power consumption?
Is the original power-line fuse present or labelled?
15 amps
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Old 23rd January 2013, 09:39 PM   #34
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Quote:
Originally Posted by JMFahey View Post
I doubt whether you actually have a problem.
The proper place for a BGW750 (I've had a lot of them, still warmly remembered) is in a rack, at either far end of a stage, behind a mountain of PA speakers.
Buzz ... !!!! What buzz ???
Are you speaking to ME? SPEAK LOUDER !! CAN'T HEAR YOU !!!!
Very true, but not in my case. The hum is just loud enough to be distracting.
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Old 10th February 2013, 03:55 PM   #35
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Default Another Update

Not satisfied with the results of my varnish soak, I decided to give the mechanical decoupling method a shot.
I found it interesting that with the xformer removed from the chassis, the hum was practically inaudible!
It took some time to figure out a scheme given the really tight fit within the chassis but I managed to do the following:
Inserted a thin dense foam pad (think mousepad) between xformer and chassis at the two points of contact, the mounting side and bottom, as well as between the xformer and right angled metal shielding plate which covers the top and side of the core.
The xformer was secured like this:
1/4-20 bolt head>metal washer>3/8" rubber grommet sliced down the middle>chassis>foam pad>metal shield>Xformer>other half of sliced grommet>metal washer>nylon nut.
The last half grommets could not be used on the underside of the xformer as there are speednuts mounted there and quite unreachable.
1/4"grommets went between the shielding plate and underside of the chassis.

The result? A significant improvement! It is not totally silent, I suspect a little transmission taking place through the bottom speed nuts but not much can be done about that.
For the moment, the noise level is acceptable. Depending on my level of OCD and or boredom, I may re dip and cook the Xformer when the weather permits.
Thanks to all who chimed in, hopefully this will help someone in the future.
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