Hi Jonathan
Could you tell me a little more about this device? I have a persistent low level hum in my Aksa TLP preamp that I built and I am wondering if this might help me.
Sure. I had what turned out to be
two hums in my Unico integrated amp that were driving me nuts. One was a VERY low level hum coming from inside the amp that turned out to be the toroidal transformer itself (it hummed whether anything was plugged into the amp or not). I had been advised that turning it somewhat might help; however, when I went to try this I discovered that the transformer was loose enough to turn by hand, and simply tightening down the bolt that secured it to the chassis seemed to help with the hum. In any case, at this point it's nearly inaudible and is not a problem.
The second hum was the one that was killing me, and I nearly sold the Unico as a result of it (glad I didn't). This was an audible 60 cycle ground hum that I discovered was being caused by the cable TV line (it was loud even with the TV turned off, but REALLY loud with the TV turned on).
My setup was as follows: Coax cable line from outside running into a VCR and then out to the TV (audio and video outs from VCR also connected to the TV with Radio Shack cables); my DVD/SACD player was attached to the TV via a set of RS component cables, with the stereo audio connected to the Unico with a pair of Kimber PBJ interconnects.
The problem was that as long as the cable line was in any way connected to the TV (either directly or through the VCR), any connection between the TV and the amp would cause a nasty hum from the speakers. So, if I wanted to listen to SACDs, I'd have to unplug the cable line or the component cables from the TV. if I wanted to listen to a concert or anything on TV through the speakers, forget it--too much hum.
Anyway, I ended up doing a Google search under "cable TV ground hum" and came upon numerous suggestions for eliminating the hum, including transformers for up to $650. Then I saw a transfomer being offered by someone over here (Byteme, I believe) for around $17.00, but this price seemed high for such a simple connector, so I continued my search until I came across the Calrad DC ground blocker and isolation transformer, which looked just like the piece being sold for $17.00. I ordered one for $5.85 (delivered within a week or so via the USPS), inserted it between the incoming cable line and the TV, and VOILA-- no hum AT ALL.
Now, it may be that what you're hearing is just your transformer humming and not a ground loop, in which case this thing isn't going to help you. You may want to try playing with the transformer a bit (
be sure the power is off and the caps are drained). As I said, sometimes turning it or tightening it can help. If your system is connected in any way to your cable TV, though, try the Calrad piece. It works perfectly. Good luck,
Jon
