[doug s.]

hi all,

i say it's strange, cuz, having done no changes to this system for a couple months, it yust started humming, & the only cure was to insert cheater plugs on the amp power cords.  wazzup w/that?

equipment included creek obh12 passive pre, z-man ase tube buffer between the creek & the wave-8 amps.  the creek also sends signals to a pair of powered yamaha yst-305 subs.  sources include two tunas, & a cdp feeding a modded art di/o.  speakers are coincident victory's.  isolation transformers abound.

any clue as to why it would suddenly start humming?  it's more outta curiosity than anyting else, as the cheater plugs made the hum go away, i am now trying different amps (haven't tried 'em w/o cheater plugs), & my melos pre will get re-installed in the next coupla daze...  it's yust weird that, after two months of no noise, it would suddenly start humming.

thanks,

doug s.

[mgalusha]

Doug,

You might check the preamp or the amps for a small resistor between the circuit ground and the chassis ground. Some designers use a resistor between the circuit and chassis grounds to reduce hum. I have them then fail and this can cause a sudden, unexpained hum. The ones I can recall were somewhere in the 10 to 1000 ohm range.

The one I had problems with failed open and I have read of others having similar problems.

Mike

[rosconey]

cable
i got a hum out of nowhere from cable

[mcgsxr]

I had a DIY cable go on me too -  a coax one I was using for my sub, grounded itself (super noob soldering twit...) and hummed.