532 amp hum

[e093116]

Hi,

I've noticed an annoying hum with a 532 amp in a 2204 phono. The amp has been recapped and has good sound quality/output (other than the hum).

The hum is of consistent intensity.  It is present if I unplug the lighting plug and/or the turntable RCA input.  It's also there/independent of the volume control setting.

I did replace the line cord with a 3 conductor cable/3 prong plug, however, I did not connect the 3rd wire (green) to anything on the amp side.  It is connected on the wall plug side.

Any suggestions or things to try/check? 

Thanks,

Bill

[Ron Rich]

Hi Bill,

IMHO one should NEVER install a three wire cord, with out connecting it --PROPERLY-- ! (also, IMHO, one should not install a 3 wire cord on any equipment that originally did not have one).

The "amp was re-capped--" WHEN ? Not sure, bout a 2204, but some of that vintage WurliTzers, had separate " power supplies"--if that's the case here, when was the last time it was serviced ? Ron Rich

[jukeboxmarty]

The 532 amp does not have a separate power supply. Just because the filter caps were replaced does not mean that the replacements are not faulty. The 3 wire line cord should not introduce or eliminate hum, but as long as the 3 wire cord is there, the green wire should be attached to the chassis on the amp side.

One common cause of consistent 60 cycle hum is from bad filter capacitors.

[e093116]

I finally got back to figuring out this problem.  Turned out to be the jumper plug for the volume control.  I got rid of the plug and hardwired the socket from the bottom side.  No more hum!