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previous: 6 10 Hi Smokey.Well, one reason ... -- 7/5/2003 7:39 PM	View Thread

Re: Transformer layout

7/7/2003 2:30 PM
steve conner	Re: Transformer layout The power transformer can radiate magnetic field into the output transformer, causing hum in the speaker. You'll know if you have this problem because the amp hums even in standby (weird) If you use a circuit with plenty of NFB then the hum actually goes away when you flip from standby to on. You can cancel out this hum pickup by rotating one of the trannies so that the windings are at 90 degrees. Then you can mount them closer together. That's probably how the Bogen amps that another poster mentioned were built. Steve C.

7/7/2003 2:30 PM

steve conner
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Re: Transformer layout

The power transformer can radiate magnetic field into the output transformer, causing hum in the speaker. You'll know if you have this problem because the amp hums even in standby (weird) If you use a circuit with plenty of NFB then the hum actually goes away when you flip from standby to on.

You can cancel out this hum pickup by rotating one of the trannies so that the windings are at 90 degrees. Then you can mount them closer together. That's probably how the Bogen amps that another poster mentioned were built.

Steve C.