This will be a little tale of the above, and may it work for others if the occasion arises.
My Aksa's, amps and preamps were all constructed in 2003, 2 amps and a preamp. The amps eventually became Lifeforces, and were changed in cases a time or two. The preamp has gone thru various parts modifications and case changes as well over this same time. In all this time, my American amp has been fairly quiet, and dead quiet with recent changes. At the same time, my Australian amp-preamp combo has always had a bit of a hum in it. It was very low level and untroubling. I thought it was something to do with the tube buffer stage as all tubes do leave a small noise fingerprint.
This was all well and good until a couple weeks ago, when the hum issue entered a new dimension in the Australian system. The hum roared up and would not go away. I couldn't listen to music anymore. I began dismantling everything in every box trying to find the culprit causing this calamity. But I couldn't find anything awry. I even rewired the preamp to just an attenuator state, so a to simulate my dead quiet American system that had the same exact modified cd player, though different speakers. The hum stayed. This was deeply perplexing as everything was the same other than a few seemingly minor details that couldn’t possible amount to a hum problem. Yet, I most certainly had one.
I did google searches and learned all about ground loops in large studios and in large A/V systems. But I have a simple two box system and no ground loops.
I searched the Aspen forum for hum and star earth, and read the old threads and posts, including some by me.
But there, late on New Years Eve in the 100 degree New Years Eve heat no less, I saw a picture of someone’s amp, and there was this little wire running from the heatsink to the star earth. I wondered what this little innocuous looking wire was doing there. Nothing in anything I’d read here mentioned heatsink earthing or chassis earthing. I thought chassis earthing was to be avoided. Nonetheless, there was this little wire. I had begun to think about a chassis wire to star earth as a last resort guess of some sort as I knew the heatsink was not electrically connected to star earth but was connected to mains earth on the chassis.
Anyway, a few minutes later I had the deed done, the wire connected and I reconnected everything up ready for another runup of the attenuator listening for the hum from the speaker. And I didn’t hear the hum. I double checked to make sure I had the amp on. I put a disc on to make sure sound would come out of the speaker. I heard music. I stopped the disc and heard only silence. I turned the volume up to full blast, and still only silence. I couldn’t believe that this little wire was all it took to rid my system of 8 years of hum. It seemed too good to be true. I played a whole disc to bring in the New Year, and left everything as it was for the night, afraid to touch anything lest the silence disappear and the hum return. But the next morning the system was still silent while on and playing.
I then set about reassembling everything, including returning the preamp to actual preamp status, afterall, I had thought for 8 years that the preamp was the source of all humming, and now I would be sure to know. On came everything and I turned up the volume and all remained silent, and then I took my hand off the volume knob, and the hum returned in an unmistakable way. I retouched the knob and silence returned. It didn’t take me long to figure out that the preamp was grounding itself with ME. And it took even less time to figure out that another chassis grounding wire from board to chassis would be needed.
And all has remained silent ever since.
I didn’t mean to write such a long tale, and may all who read it find it entertaining. There haven’t been the hum threads in the past 2-3 years like there were 5-6 years ago, but the issue still comes up on occasion. And a chassis to star earth wire may not always be the solution. But if you are like me and never thought it was supposed to be there, and have just put up with a little hum from time to time, well, these amps can be DEAD SILENT.
And the GK-1 can be DEAD SILENT as well, tube buffer stage and all.
HAPPY SILENT MUSIC NEW YEAR!
