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In the Forum: Analog Playback
In the Thread: The last phonocorrector: “End of Life" Phonostage

Post Subject: More findingsPosted by N-set on: 11/23/2011

I did one thing: I swapped the phase of one of my PS transformers (the heater one).
My PS transformers are placed parallel side-by-side and super close to each other.
Very wise, but I had no choice. I tried to wire the primaries
out of phase to have some cancellation, but what one can expect from a person who notoriously confuses left and right?
I had done it wrong. Swaping the primary reduced 2x the emitted garbage (as certified by a search coil and a scope)
More importantly, it also gives me finally no hum at my desired orientation of the boxes with the signal box open.
(but at certain other orientations I still get an audible ham). The drawback is that the trannies seem to
be noisier a bit.

Interesting thing happens when I lift the ground. A terrible magnetic pick-up brum appears as usually and I have
no clue why. But it is
sometimes enough to rotate the box by a very small angle to shut it down completely...

All this seems to point to my PS as the source of the garbage. And this is the "reward" for my heroic fight,
huge oversized tarnies with tripple screens, box sectioning, grounding of all metal parts,expensive SiC diodes, etc, etc!!!
My case does not properly magnetically shield--front and back pannels are thin alu, only top, bottom and sides are steel.
The RF noise is also there (the hiss increases when I move PS very close, I also saw a 30kHz pollution
correlated to a glitch in the HT switching).
Either my implementation is shit (most probable) or perhaps all that soft switching SiC's is just a pile of BS.
I'll get a 10km umbilical to put all this misery in another city.

Cheers,
N-set

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