DC offset/humming/P10/P15

Power Components
1

I have a DC offset problem on my mains… and humming transformers in my amplifiers :frowning: .

Part 1

I tried a friend’s P10 with my amps, but this did not help. So my deduction is that the toroids were just badly wound and it wasn’t just the DC offset which was causing the hum.

Key assumption to support the above deduction: Am I correct that the P10 (or any of the PerfectWave or DirectStream regenerators) won’t have a DC offset on its outputs? After all, they are going from AC -> DC -> AC.

Part 2

My amp manufacturer has done the right thing and swapped out the “bad” pair of PSUs for a pair of factory-measured “good” PSUs, but these also hum in my environment… To date, I’ve not been able to try these new PSUs with a regenerator of any model. A DC blocker does helps somewhat, but does not alleviate the problem completely.

Am I correct in thinking that the P15 has a DC blocker built-in (presumably on the mains input side) and the P10 does not? Does the DC blocker on the P15 input simply start the clean-up process earlier? It strikes me as something which, whilst not essential, could be “useful” in my environment.

2

The P10 certainly doesn’t block DC, can’t say whether same applies for the new series power plants.

1 Like
3

All new Power Plants have DC blockers.

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4

Paul states here that the P10 does block DC.

https://forum.psaudio.com/t/audible-hum-from-the-bhk-300-monos/3212/5

5

But is Paul referring to the intrinsic DC removal of an AC -> DC -> AC regenerator? My understanding is that the new DirectStream units have a DC blocking circuit in addition to the actual regeneration.