• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Hum SOLVED!!!!

i have posted here a bit about the hum in my system. its all home made, except the Turntable but i have fooled with that enough not be sure of its intentions. So i really could never figure out where the problem came from.
I have had a periodic "hum" and it has been a major source of frustration. I thought ground loop. So i spend many many hours changing stuff to no avail.
I figured that given it was a MC phono stage and it was all valves then it would just hum a bit, But sometimes it would get REALLY loud in one channel and not the other. Weird stuff i couldn't explain
Well today i installed a new cart. Same as before, Denon 103.
Perfect quiet. I mean black inky nothing. It wasn't the wiring, i changed that many times. It must have been the Cart. WTF? I guess there was something amiss with insides of the old 103? I cannot believe the difference. Its quiet. Its nice. At peace with myself :)
 
Glad you got it. I still use a Denon DL-103D. Nice old gal. Your tail reminds me of an old experience I had as a teenager working part time for a local TV & radio repair shop. I had a small kids record player that hummed. It wasn't the filter cap or a bad ground or open wire of any kind. I spent a couple of hours on it and was about to give up when just for drill I tried a new crystal cartridge. Well, that was it and a lesson I've never forgotten. Another hard lesson was a portable transistor radio that worked but motor boated. Tried everything to no avail. Turned out to be a weak battery in a series of several D cells that powered it. Arrgh!