Phono Stage Hum

Not sure what you mean by having the phono stage set to no gain. The specs at the Jolida site show 70db gain for moving magnets (which seems like a lot, btw). And I assume you have its riaa equalization in the path.

Is the hum equal in both channels?

Do you have the turntable, phono stage, and integrated amp all plugged into the same outlet or power strip or surge suppressor? If not, I'd suggest trying that, to make sure that ground offsets between differing ac sources aren't causing the problem.

Are the components physically some distance apart, so that for instance ac fields from the power xfmr and associated wiring in the integrated amp aren't being picked up through the air by the phono-level wiring.

I'm not familiar with the cables. Do they by any chance have directional markings, which might signify that their shields are grounded at only one end? If so, try them the other way.

It could also conceivably be a tube problem, such as a filament-to-cathode short.

Do you get the hum when the turntable is not turning? If not, it would suggest Grado-like pickup by the cartridge of 60 Hz emi from the turntable motor.

Also, if possible disconnect the turntable from the phono stage, and put a shorting plug on the phono input, and see if you still get the hum.

HTH,
-- Al

The gain was high for MM cartridges. I talked to the Jolida dealer, and he said that they typically recommend no gain for MM cartridges. I'm not sure what you mean by the riaa equalization in the path.

The hum is roughly equal in both channels and they are all plugged into a Shunyata Guardian.

I have had a small fear that there is a bit of crowding around the cabling. That is part of what I will experiment with this weekend.

I do get the hum when the turntable is not turning. I also occasionally get a pop when I turn it on... Something I just remembered.

Good advice on the shorting plug. That might be my first test.

Thanks,

tim

Check all connections including those to the cartridge first.

If still a problem, check proximity of the phono stage to other components and any other devices emitting magnetic fields. The power amp is a prime suspect. Move it around physically and see if hum increases/decreases. Try to locate it where hum is minimized or hopefully gone.

If that is it, I have been treating a similar issue with my phono. Check my system postings for more info on solutions involving adding additional magnetic shielding, if needed.