Hoping I can get some help with a faint hum that's coming from one of my Adcom amps. I'm currently using a GFP-555 preamp to drive three Adcom amps (GFA-545II, GFA-555II, and GFA-2535). Everything is being powered through a pair of Adcom ACE-515 AC enhancers plugged into separate outlets (on the same circuit though). I'm splitting my norm and lab outputs with Amazon Basics heavy shielded RCA splitters and cables. The 545II and 555II have zero hum.
What I've noticed on the 2535's hum is that it doesn't change as you increase the volume on the preamp. It's a constant hum. Thing is, as soon as I unplug the RCAs from either side, it's gone. This made me initially think it was my preamp, but even when plugging my bluetooth receiver directly into the 2535 it produces the same hum. It's almost as if there is something coming in on the RCAs that is causing this.
I've tried various cables, different sources, etc. No change. I have eliminated most other devices on this circuit, save a couple deep freezers that I can't move off this circuit just yet. I even removed the coax coming into my TV to ensure that was not the culprit. There are also no fluorescent lights or dimmers on this circuit.
The most recent thing I've done to try and eliminate this is connect the grounding posts of my ACE units together, along with the post on my GFP-555 (following the ACE-515's manual). No change.
Any help is greatly appreciated. While I've read this hum isn't "bad", and it's only noticeable when you're close to the speakers being driven by the 2535; it's quite annoying.
-Dibbers
What I've noticed on the 2535's hum is that it doesn't change as you increase the volume on the preamp. It's a constant hum. Thing is, as soon as I unplug the RCAs from either side, it's gone. This made me initially think it was my preamp, but even when plugging my bluetooth receiver directly into the 2535 it produces the same hum. It's almost as if there is something coming in on the RCAs that is causing this.
I've tried various cables, different sources, etc. No change. I have eliminated most other devices on this circuit, save a couple deep freezers that I can't move off this circuit just yet. I even removed the coax coming into my TV to ensure that was not the culprit. There are also no fluorescent lights or dimmers on this circuit.
The most recent thing I've done to try and eliminate this is connect the grounding posts of my ACE units together, along with the post on my GFP-555 (following the ACE-515's manual). No change.
Any help is greatly appreciated. While I've read this hum isn't "bad", and it's only noticeable when you're close to the speakers being driven by the 2535; it's quite annoying.
-Dibbers