Balanced AC possible without isolation transformer?

Does the Decware product have a balanced bifilar toroidal transformer? Bifilar toroidals weigh nearly twice as much as an equivalent toroidal.

From the Plitron website:

“The Balanced Power concept consists of a 1:1 isolation transformer (ie 120 VAC In/Out) with a centre tapped secondary winding. The ‘Balanced’ refers to a Bifilar wound secondary – meaning both secondary halves are wound simultaneously, turn for turn – thus each of the 60 Volt sections are mirror imaged and matched to the theoretical limit for resistance, capacitance, and inductance.”

I’m really curious whether inserting a Torus, Equi=tech, or PLiXiR product between the P20’s output duplex and (let’s say) a DAC would be beneficial, and further, not cause any harm to the P20.

I honestly don’t know, but can tell you that the transformer is large and very heavy. Here’s a picture from the product page:

image

If you would like to inquire you may get an answer from the designer here: steve@zenamps.com

Thanks for the photo! I’ll be reaching out to ask the manufacturer. As well as to PS Audio.

I’ve done some research using the key words “balanced power”, “toroidal”, etc. but the posts on this PS Audio forum / threads seem quite fragmented, and I can’t seem to find anyone with P10/12/15/20s having plugged a balanced (bifilar) toroidal transformer into their Power Plants. I’ll keep on asking, and looking!

I have plugged my P10 into the Decware unit. I believe there was a subtle improvement doing so, but it wasn’t significant enough for me to eithe repurpose the Decware unit from my headphone system or to warrant purchasing another so that I could have one in both systems. I’m lucky here in that I live in a wooded sparsely housed area with a less noisy than urban power (usually less than 2% noise in the line) and I think if my incoming power is worse having the Decware unit in front of the P10 might make a more significant difference. In the headphone system it’s a very good nerve-center, I really enjoy having it.

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For many years I tried to get a good sound at a low cost. I couldn’t afford big expenses and as an electronics engineer I wanted to do something myself. I have assembled several amplifiers and several loudspeakers. I remember a huge improvement in the sound when I coiled the crossover coils with silver plated wire.
And now I switch to isolation transformers.
For about 20 years I used 230/230 V, 450 VA and 200 VA transformers, each of them improved the sound of the system. The transformers themselves, without additional elements, only for safety I placed them in a suitable housing. I tried the 200 VA transformer with a pair of active Neumann KH 310 monitors, they sounded great. I made a test then with the addition of a polypropylene capacitor to the secondary winding, I do not remember what capacity, but it made the sound worse.
Two years ago, after purchasing P5, DMP and DSD, I passed the transformers to my colleagues. Everyone is happy with them, I was even asked to prepare one more and then I bought another 450 VA transformer. It was supposed to be the same as before, but this one did not improve the sound. I took measurements of the old and the new transformer. The output voltages were identical, the winding resistance also. They differed in winding impedance. The transformer giving a good sound had an impedance 10 times lower, consumed 50 mA of current without load, the transformer not improving the sound consumed 10 mA.
The transformer manufacturer informed me that the cores are now buying from another manufacturer. Theoretically, a core with higher magnetic permeability is a better core, but not in this application.

What is this assessment based on? Especially in comparison to a P3’s rather modest capabilities?

Lon, there is a similar discussion going on over at WBF about whether and how to connect a regenerator with a balanced isolation transformer. Thanks for posting the Decware IT link info above. I did not know Steve had ventured into this arena, though he has always been concerned about power quality. I am currently contemplating upgrading my speaker system P10 to a P20—thanks to PSA’s very generous upgrade policies—and also adding an Equi=Tech 2RQ. And I may add the Decware unit to my headphone rack where there are two P5s, and the Decware’s more modest capacity would not be limiting.

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Was that already in your brain? You, sir, are a pisser.

Thanks for the link G.

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Palerider,
FWIW: Your question is quite appropriate based on my experience. My Equicore 1800 (recent Underwood model) is “feeding” my 200 watt amp (plus 65" tv, plus all remaining audio kit) to maximum reasonable current demands with excellent results…quite improved over previous wall outlet to vintage/dated conditioner (via custom direct line from breaker box, now feeding the Equicore, of course).

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Thanks @jedi1.

It’s based on Paul’s advice. He stated that Equitech makes fine products but that the surplus impedance introduced by the transformer would be detrimental if the goal is to drive a power plant ideally. (Not the P3 specifically but I trust he knows best what his power plants like to eat in general)

Of course Paul agreed that a big enough transformer negates concern but he sees little point in balanced mains. I see a lot of point in it, especially in terms of whole-house solutions because having the house NOT act as a huge antenna seems like a huge benefit. There’s enough radio pollution already, I don’t want it running along my length of copper. I see balanced mains as equally important as balanced audio.

I have two P20s and was wondering whether it would be OK to connect balanced toroidal isolation transformers between the P20 and a source component. Please post your comments, if any - thanks!

You can do that but I would question the need and would also be concerned you’re taking a step backwards in sound quality.

The only benefit to balancing the power after the regenerator would be to gain a small amount of common mode rejection of what’s in the connecting power cable. It’s unlikely, if you have a decent power cable, that it’s picking up anything worth worrying about unless it’s a very long power cable.

I’d not do it if it were me.

Got it. Thanks for the follow up. I ended up replacing my P10 with a Torus AVR2 20. I still intend to replace the panel that supplies the power to that part of the house with a balanced box, also likely a Torus.

Hey Paul, thanks for your response. While the P20 is an amazing piece of technology, it’s abundantly clear to me that it’s still extremely sensitive to the input AC power cable (I’ve auditioned/compared many different ones myself, and heard significant differences), hence not invariant to even minute differences in the quality of the incoming AC. While the P20’s regenerated AC is darn-near perfect, it still has meaningful amounts of noise - perhaps not so much common-mode type (alluded in your reply above), but mostly high-frequency spectral noise. It is the latter, plus AC offset noise, and ground-pin DC noise which can all be removed by a high-quality balanced toroidal isolation transformer; a power-capacity rated at 3-5x the component’s power draw for extra headroom will ensure that there will be negligible current constraints for the power supply of source components (not power amps).

BTW, why aren’t there more objective noise measurements (of the P20) published in the public domain? I would be thrilled to see detailed spectra graphs of the amplitude and frequency of the noise in both the post-regeneration AC line noise, and on the ground pin. Surely, it can’t be that difficult, with an oscilloscope interface?

Big fan of balanced power here.

Had my entire system powered by it for the last 7 years, really big improvement over straight from the wall.

All started when a friend (Electrical Site engineer) of mine brought over his DIY balanced mains box at a bake off at mine and the improvement was night and day - my mains were officially terrible.
Got me thinking and I decided to get balanced mains in my system,.
Went a step further and hard wired my BMU unit (2KVA rating) into mains, and from that a hardwired “hydra” block Feeding iec power to all my bits of kit.

The impedance concern was always at the back of my mind though, and on my next major upgrade (when I got my PS Audio gear) I looked again and improving the mains if I could.

Decided to take the nuclear option to set and forget.
All power cables upgraded to silver Wireworld and to eliminate any possible impedance niggles, I swapped out the 2KVA rated balanced mains unit for a FAR lower Impedance 10KVA one.
My friend is an electrical engineer and Site Mgr who installs Multi KVA power substations, so took my advice from him on safety aspects, as the install was quite hardcore.
We fitted twin pole RCBO circuit breakers on both primary and secondary windings and the install was signed off by an electrician.
So all good.

Nowadays have lost the “Hydra” and have a single tail coming from the BMU feeding a double socket, from that have a Wireworld mains block.
Simpler and better than good enough.

The BMU has multi taps for different incoming voltages, so tried a regen unit (not a PSA Unit) to test the value and stability of voltage so I could use the correct tap for my mains.
I’d considered a P20 when buying my DS and BHK, Didn’t find the regen unit made anywhere near as much of an improvement.
P20 would have been different of course, but it was that or my BHK Pre, which I felt would have made more of an improvement.

It’s a Big mother!
Stored away out of sight and not in the listening room happily.



To get the 10KVA rating, two massive toroidal Transformers inside.

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This is the balanced toroidal isolation transformer I’m considering - two units, connected after the P20, for the two mono powerbases powering my MSB Technology Select II DAC:

The PLiXiR Elite BAC400 is good for powering components adding up to 250W (total), according to the guidelines from this 2017 German review:
https://6moons.com/audioreviews2/plixir/1.html

The caveat (I’ve learned) is to make sure they’re plugged into the High Current duplex of the P20, because their power draw upon turn-on can be so immense that they may pop fuses and breakers.

Looks well designed John,
Like everything in audio, all about what it’s used with.

Will improve rather than take away from sound quality, so a good investment.