Another cause of 60 cycle hum that’s worth a look.

[AnotherJohnson]

I recently went through the kabuki dance of auditioning s McIntosh MA5200 in place of the ET7S2 and LP275Ms.

Yes, it ended with the obvious result, ie. Low powered entry level integrateds don’t hold up against CJ separates.

But … after I’d removed the McIntosh and hooked up the CJ, I had a 60 cycle hum on the left.

When people ask about this, we often advise them about ground loops, power supply caps, interference and transformers.

But last night, the low hanging fruit was that the interconnect from the ET7S2 to the left LP275M had been jostled … it had not been displaced by any more 1/16”, but it was enough to compromise the ground. Pushing it back snug was quick and definitive.

So … if you’ve got some suddenly appearing 60 cycle hum, shut things down, and walk through and clean your interconnects … it’s free. Don’t trust your eyes. This interconnect did not look like it had come out. I just by force of habit pushed all interconnects and speaker wires “home” and that was the one that actually moved.

[admin]

Yup, wise words. Always start with the basics.

[roberto]

We have a saying here: best monkey, mango fall. In other words, we could do something wrong or it just happens.

Happy listening!

[AnotherJohnson]

Mmmmmm …. Mangos ….