gfinlayson
Member
Bill,
If your amps and preamps require earth connections, then effectively by using 3 to 2 pin plugs you are removing the earth connection to the equipment chassis. This earth is provided as an electrical safety feature, and is mandatory.
The fact that it's plugged into an earthed line conditioner makes no difference, as the equipment chassis is still not earthed.
If you can give me a run down of all of the equipment that is connected together, I'll see if I can come up with any suggestions.
Graeme
P.S. I've had a persistent earth loop problem myself for some time which I've finally solved. My main hi-fi speakers and associated pre and power amps are used as the front channels on my A/V system.
If I disconnected the analog connection from the TV, the ground loop hum was still present. If I disconnected the SP/DIF from the DVD player as well, the hum stopped. It turns out my cable TV box audio ground shares the same ground as the incoming coax cable (which is earthed by the cable company for safety reasons). Even having no direct audio from the cable box still caused hum, beacause the SCART leads on the DVD and cable decoder have a common ground which is shared by the DVD's SP/DIF and this was ground looping via the Dolby digital processor to the amps. The solution was to switch the DVD to TOSLINK, and I was going to put audio transformers in the analog outputs from the cable box, but our cable provider is now doing new TV Drive boxes which have TOSLINK digital output. Now all of my music stuff is connected by RCA phonos, and all of the video sound stuff is connected via optical digital. No more hum!!!
If your amps and preamps require earth connections, then effectively by using 3 to 2 pin plugs you are removing the earth connection to the equipment chassis. This earth is provided as an electrical safety feature, and is mandatory.
The fact that it's plugged into an earthed line conditioner makes no difference, as the equipment chassis is still not earthed.
If you can give me a run down of all of the equipment that is connected together, I'll see if I can come up with any suggestions.
Graeme
P.S. I've had a persistent earth loop problem myself for some time which I've finally solved. My main hi-fi speakers and associated pre and power amps are used as the front channels on my A/V system.
If I disconnected the analog connection from the TV, the ground loop hum was still present. If I disconnected the SP/DIF from the DVD player as well, the hum stopped. It turns out my cable TV box audio ground shares the same ground as the incoming coax cable (which is earthed by the cable company for safety reasons). Even having no direct audio from the cable box still caused hum, beacause the SCART leads on the DVD and cable decoder have a common ground which is shared by the DVD's SP/DIF and this was ground looping via the Dolby digital processor to the amps. The solution was to switch the DVD to TOSLINK, and I was going to put audio transformers in the analog outputs from the cable box, but our cable provider is now doing new TV Drive boxes which have TOSLINK digital output. Now all of my music stuff is connected by RCA phonos, and all of the video sound stuff is connected via optical digital. No more hum!!!