I’ve got an intermittent DC Offset on my mains, which causes the 1000VA toroid of my power amp to buzz occasionally. I attempted to solve it with an isolation transformer (a Hammond with an EI core, which doesn’t suffer so much with DC offsets). Unfortunately, it sapped some of the life of the music, hummed a bit itself, and also got warm to the touch.
Later I acquired a P12, considering it as a possible solution. Then I started learning that it may not fully address the situation. Messaging regarding the models varied, but it seems that some/most/all Power Plants will suffer from DC offset on their own toroids, even if the regenerated power doesn’t have a DC offset.
Hence my question: Do any of the Power Plants block DC offset on the mains before it hits their own transformers? As I mentioned, I’ve got the P12 myself, and a friend has the P5, so I’m wondering about those in particular, but I would love to see a definitive list for all the models, just for information’s sake.
BTW, I’ve since built a DC Blocker using the DCT03 from Sjöström Audio. This completely solved my DC offset problem for my power amp (without using the P12).
If the P12 doesn’t manage the DC offset itself, could I put one of these Sjöström units in front of the P12?
The Power Plants do not offer DC Blocking. In the past Paul has recommended a product that may alleviate DC offset concerns. The Puritan PSM156 does offer DC Offset Blocking, FYI.
I wouldn’t put that much filtering in the path of my mains. As it is, the P12 has insufficient ability to drive my power amp. It saps a notable portion of the life of the music.
That’s why I’m pleased with the Sjostrom DCT03, as it does DC blocking and nothing else. It’s the only thing between my amp and the wall, and it resolves the DC offset without diminishing the musical excitement.
I’m hoping that the P12 will be appropriate for my other gear which requires less current. I won’t have a chance to test that for a few weeks, though.
I tried one of those. Wasn’t at all sure I had the problem it cures, and man did it introduce bad vibes to my sound. Just did not help and in fact mad things worse. The only really good thing about it is that it’s diagnostic tool told me one outlet on one wall was wired incorrectly. I’ll thank it for that.
What works extremely well as DC-Blocker in front of PS Audio Powerplants is the ISOTEK EVO3 Syncro Uni. The sound significantly improves and hum problems disappear. Not so expensive as well.
I had DC problems with my P20 and I can confirm that it audibly betters the sound quality in my highly resolving horn based system and it also removed transformer hum in my tube amps. There was another positive report on that device somewhere in the forum recently.
Agreed! I could have populated the board myself, but in this case I chose to purchase the pre-populated board, which I mounted in an ABS enclosure with a captive lead and hospital grade receptacle. It was relatively inexpensive and served my purposes quickly and relatively easily.
Hi There, sorry you got bad information. I had the same question and asked the support team, this was their response in regards to my query about the PP12:
In any case, I belive you are asking about our PowerPlant products… Our current generation of Powerplants do block DC, 2V to be specific. The output DC will be less than 50mV if there is less than 2V on the line.
