Balanced power compatabilty census


I have run across some equipment that does and does not work well with balanced AC. I thought this forum might help others, if supported. In my case, I used 5KVA transformer and one piece of gear at a time.

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If you are unfamiliar with "balanced AC", it refers to 60 volts +/- as referenced to ground and hot/neutral are 180 degrees out of phase. Normal (North America) power from outlets is 120V on hot leg only. Equi=Tech, Balanced Power Tech. and DIY projects convert single phase to dual phase with the "promise" of reduced noise. In some cases, sonic improvemnt can be more than just reduced noise. In other cases, the grounding scheme of the equipment may not be compatible. Don't jump to conclusions that because one experience or model worked or didn't, that it reflects on the brand or type.
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Genesis Stealth amp did not work properly but I suspect problem is due to active x-over.

Plinius SA100 mk3 worked better but no better than simple isolation.

Sonic Frontiers SFL-2 loved it and had immediately noticeable improvement.

Manley Snappers sounded compressed with balanced AC. Odd for differential amp.

I have yet to try with sources which have separate isolation.

Does anyone else have have positive or negative reports?
ngjockey

Showing 2 responses by john_tracy

All of my system is plugged into an Equi-tech 2Q and everything loves it. System is very quiet. No ground loops. All grounds referenced off CT of the 2Q. Front end: K&K phono pre (kit), Cary CD-308 (used as transport), RAKK DAC (K&K Audio kit), Fisher FM-100b (modified). Raleigh Audio line stage (kit, K&K Audio) and currently a restored Eico HF-89 (gutted and rebuilt and modded by me). The line stage is transformer coupled input and output using Lundahl amorphous core tannies. It's a differential parafeed design. The phono pre has a SE parafeed output using same Lundahl iron as does the RAKK DAC which uses a transformer and resistor to provide passive I/V conversion. I think having the galvanic isolation provided by all the transformer coupling can reduce the chance of a bad interaction; no ground currents on the interconnects. One of the mods on the Fisher was to rewire it for a three wire IEC connector.
Neil, had the 3 wire PC conversion done so I could use a better power cord. I had that mod done by the tech who serviced and aligned the Fisher. Can't be too hard; I wired my Eico that way. The two "hots" to the power transformer and the ground to the chassis. Digi-Key sells IEC connectors with built in RFI filters that are kind of cool. My Sun SV-2A3 kit came with one and I used one in the Eico and the RAKK DAC that I built. Anything to kill some of the crap that's coming over the power lines these days. Can't imagine what it will be like if they start sending internet data over the power lines.