[Darterboy]

I built a Bugle and the power supply from half-kits several years ago and mounted them in an enclosure. They've never given me a bit of trouble till yesterday, when I selected the phono input on my pre-amp and had a loud 60-cycle hum in both channels. The loudness of the hum diminishes when I unplug the turntable interconnects but is still there. It persists after I cut the power until the LED goes dark. I've tried removing the turntable ground wire with no effect. I haven't added or re-configured anything with the system recently.

60-cycle hum is usually ground-related, isn't it?

I've considered lifting the ground wire from my mains ground but haven't yet to see if it would have an effect.

Any tips on how I should begin to troubleshoot this?

-Stott

[PatOMalley]

did you plug the Bugle into the Phono Pre or did you take the tonearm wire out of the Bugle then plug it into the phon pre on the preamp? If you did the second did you run the ground to the preamp?

[Darterboy]

I lifted the ground from the Bugle board to the mains ground and poof! no hum. Why on Earth did this not rear its head for nearly 5 years? Is it safe to run it this way? (wooden enclosure)

[Darterboy]

did you plug the Bugle into the Phono Pre or did you take the tonearm wire out of the Bugle then plug it into the phon pre on the preamp? If you did the second did you run the ground to the preamp?

I don't have an actual phono pre on my integrated HT amp, thus the Bugle is plugged into "VCR 2". That's the input I select on the amp when I want to listen to vinyl. I did plug the TT into another line-level input on the amp to see if I could hear hum coming from the TT- no hum. I tried the TT ground wire attached to the amp and not attached, no difference.

[PatOMalley]

try tagging the ground to the chassis of the line preamp.

[hagtech]

Sounds like a broken wire or interconnect shield.

jh