Originally Posted by NutFlush
1 When you connected just the Oppo to the amp were there any other cables connected to either the amp or the Oppo? It is vital to disconnect all cables from the two components. If you leave any connection say from the amp to your set top box you may have a ground loop going through the set top box (in through the cable from the amp and out into the antenna or through the power plug even when switched off, because the ground is NOT cut off even then).
2 Also make sure the subwoofer is disconnected (not just turned off).
3 This should leave you with: 2 power cables, 1 audio cable from Oppo to amp, several speaker cables. Nothing else!
4 Are you using 2 power cables that both have a ground? Does the amp have a ground receptable for the power cord?
5 Does your amp allow a "ground lift" (physical switch or maybe in the setup)? What model is it anyway?
6 Try placing the OPPO as far away from the amp as possible. Maybe the amp induces a current in the OPPO.


1. By "amp" presuming you mean headphone amp as the Oppo would never go to the power amp directly. With only the 1 pair of analogue RCAs from Oppo to headphone amp, its all fine (when the power amp is on too). The STB issue was what seemed to occur in scenario 2. I might try disconnecting STB and antennae entirely though just to eliminate that possibility.
2. Yes, was disconnected
3. Are you suggesting trying with Oppo and power amp on, cable to headphone amp (but headphone amp turned off(, speaker cables and that's it? That's what I had last night + inputs from the Meridian to the power amp, which I had not disconnected. But it was this scenario that worked ok.
4. Yes as far as I know (3 pins, Aust plugs); 3 pins on the IEC end too. Ground receptable?
5. Do not know. Model is Redgum Audio RGH900 6 channel MOSFET power amp - an Australian company.
6. It's as far apart as it can be already. I'm still learning about this, but inducement doesn't seem like the answer.

I have to do some work tonight (spent the last 2 nights playing with the cables), so I will to complete all the various suggestions Friday/Saturday.

Thanks again to all.



Last edited by markg; 2009-10-22 12:44.
568.2mm, M80