Tech Square

Technical and speculative discussion of amps, cables and other topics.

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RE: Ground (How to test?)

Posted by shermanr@prw.net on May 29, 2009 at 11:00:58:
Very well explained and detailed. When chasing hum and noise, I would try to test separate components from each other. If you have headphones and a preamp jack this also is a good aid.

Systematcally build the system up, connecting the minimum.

Almost best to disconnect any preamp from your amps, and listen to the speaker for noise/hum. This was it rules out the amp, preamp interface.

Phono hum can often be the turntable itself, the cartridge and platter interacions, and sometimes pretty bizarre interactions.

Carefully move your cartridge over the platter and see if the hum level changes, be careful of the needle. If you dont hear any change, the arm, platter magnetics are not the problem, or at least not showing itself.

The last resort Cheater Plug method can eliminate coupled Chassis/safety and DC ground interactions.

The electrical purpose of the ground rod is to divert faul currents, lightning, and provide a reference for the neutral wire from the power feed.

A certified electrician can probably re-connect the often lossy compression adapters used in residential ground systems, cadweld's common in Telecoms are one good tweak....

Good luck!