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In the Forum: Audio Discussions
In the Thread: It’s mad, mad, mad... electricity.

Post Subject: PP and balanced ACPosted by manisandher on: 9/5/2012

Hi Jorge.
Firstly, be very careful if you're thinking about feeding a PP with a balanced AC input. It may be different with the North American PP units, but my UK unit did not like being fed by a balanced AC input. My balanced transformers already tend to increase the voltage by about 5% ,so I had an output of +115V(regenerated) and -128V(non-regenerated) from the PP (I had the PP set to output 230V). This caused havoc with my DAC especially. My conclusion is that my PP2000 only regenerates the Live input and passes the Neutral input un-regenerated. I'd be interested in anyone's thoughts here.
So, I currently have things set up like this:
house AC (240V) -> PP2000 (set to output 230V) -> balanced transformer primary (L=230V, N=0V, E=house) -> balanced transformer secondary (L=+115V, N=-115V, E=dedicated rod)
(I would draw a diagram but I'm working away from home and don't have the software on my laptop.)
All AC wiring from secondary is Belden with shields connected at both ends. At the moment, the PP2000 feeds two 5KW balanced transformers. Once the new PP+ comes, I'll have the above setup replicated twice.
I'm no expert, but I think one of the reasons this setup works so well is that the +115V/-115V outputs from the balanced transformer are not connected to E, so the earth remains 'clean'. I know that Romy has misgivings about daisy-chaining anything before or after the PP, but for my part, this is easily the best sound I've managed to get. Oh and I'm not sure if this is important or not - my system is fully balanced too. My understanding is that many studios use balanced AC, and of course use fully balanced setups (though I may be wrong here).
Mani.

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