Power Conditioning for Switching Supplied Components

Adamay · « **on:** 25 Apr 2006, 06:08 pm »

Hi. Occam's posts in the Nuforce circle have really gotten me intrigued but, to tell you the truth, the thought of making a Felicia gives me the willies. (In a past life, I made a Jon Risch power conditioner and a Risch digital isolation filter, but now I've got a 4-year old and am less up to mucking about where I have too little experience/knowledge.) So... Question: if I want to get a commercially-made version from Ebay, what am I looking for? What different types of options -- balanced, or filtering, or ... (whatever) would improve the performance of a pair of Nuforces? Thanks a bunch.

Occam · « **Reply #1 on:** 26 Apr 2006, 01:51 am »

To my knowledge, there isn't a readily available solution on Ebay, other than the occasional balancing powerconditioner from Furman, with which I've no personal experience. I have heard NuForce amps (8.xx), on a BPT balancing conditioner, as well an Audience Adept, both of which provided substantial benefits. But I'd assume you'd be far more likely to find these on Audiogon, at typical reseale prices for audio components that are in demand

.
As you've already built a Jon Risch digital isolation filter a Felicia -
http://www.audiocircle.com/index.php?topic=18441
should be no problem. The Felicia is based upon Jon's design and really isn't very different in implementation. For source components, the Felicia's limitations with regards to voltage droop, isn't overly problematic for these devices for they can operate over a large range of AC mains voltages. And for those with 220-240vac mains, the typical downrating required of transformers to operate on 120vac balanced, is not a limitation, and appropriate transformers are available from RS, Farnell, JPR....
Anyone in the NYC area with a Nuforce preamp would be welcome to try my Felicia in their own system. For those outside the NYC area, I might be able to find a willing owner to provide a short term loan. PM me if interested.

Nuforce amps would not be so easily adressed due to the increased power requirements, although not as demanding as typical class A/AB amps. Obviously, properly sized balancing conditioners from BPT, Blue Circle, Equitech, Dodd, etc... should work quite well, as would the Audience Adept. This list is by no means comprehensive, and other products such as those from Running Springs, PowerWing, SoundApplication, etc... might work quite well, though I can't personally vouch for them.
There is a DIY version of a Shunyata conditioner is here -
http://www.10audio.com/diy_power_conditioner.htm
It appears to simply be the 'Auricap Tweek', a simple capacitor(s) accross hot and neutral, except it actually uses capacitors rated for the task. Given that, I'm quite surprised by its purported benefits.

Anyone with actual experience with various powerconditioners of switching PS sources and amps, please share your experieces.

Adamay · « **Reply #2 on:** 26 Apr 2006, 02:38 pm »

Thanks very much. To clarify, do you mean that the Felicia certainly will provide enough power for digital sources, but may not provide enough power for a pair of Nuforces (I have 8.02s)? Or you think it might, but aren't sure? Thanks again.

Occam · « **Reply #3 on:** 26 Apr 2006, 03:40 pm »

Adamay,

Given the efficiency of the NuForce' 8.02's power supply and that of the amplifier itself, a Felicia per monobloc, if rewired for 240vac output (even when fed 120vac), might work without dynamic limitations. But I'd not recommend doing such without first testing. There are some folks who are quite pleased with a standard Felicia powering their gainclones. If you're in the NYC area, I could reconfigure my Felicias as a test bed. I also have larger transformers which would provide even more power. But unless you've access to existing Felicias as a 'proof of concept', I wouldn't recommed commiting to such an unproven approach.

FWIW,
Paul

mcgsxr · « **Reply #4 on:** 26 Apr 2006, 03:57 pm »

I have run multiple components off my Felicia, and have not noticed any deliterious effects.

But, those components were not high powered devices.

At present I run the following off my Felicia:

1 - Bolder Cables Rev 1 PS for my modded SB3
2 - either my dual mono 50wpc gainclone amp, or my JVC EX-A1

They run great, and sound better with the balanced power in the loop.

commsysman · « **Reply #5 on:** 26 Apr 2006, 04:07 pm »

You said something about "balanced" in there...not sure of the context.
If you are talking about a system with balanced interconnects as opposed to unbalanced...power conditioning is moot.
Systems with balanced interconnects throughout do not have issues with ground-path noise or oscillations, so there is no need whatsoever for a power conditioner, unless you are one of the 1 person in 1000 that lives next door to a large manufacturing plant or other egregious noise source.
If you are using unbalanced interconnects, then you are doomed to wander the halls of the damned, forever experimenting with cables, power cords, and conditioners, trying to sort out and minimize the myriad ground-niose problems.
When will they ever learn; go balanced and leave all of those problems behind!
Ever see an unbalanced cable in a recording studio??? Not me.
That should tell you something.
They don't have time to fool with tweaks; they need perfect sound all the time, and they get it, with balanced interconnects.

Adamay · « **Reply #6 on:** 26 Apr 2006, 04:55 pm »

Alas, Occam, I'm in the Great Plains, nowhere near NYC. I'd love to try out a Felicia before building one.

Occam · « **Reply #7 on:** 26 Apr 2006, 07:50 pm »

Adamay,

Wouldn't you like to move yourself and family to NYC? We're all quite charming and easygoing hereabouts

.
While a Felicia for NuForce's preamps should be a slam dunk, until I can personally vouch for a DIY or cheapskate power conditioning solution for your NuForce amps, I gots nutt'n. If someone local to NYC with 8s wants to be a guinea pig, we can examine a balancing solution (Felicia), and/or a CMC based solution, Felix, a diy Audience Adept.

Commsysman - Welcome to AudioCircles!

Quote from: commsysman

You said something about "balanced" in there...not sure of the context.
If you are talking about a system with balanced interconnects as opposed to unbalanced...power conditioning is moot.
Systems with balanced interconnects throughout do not have issues with ground-path noise or oscillations, so there is no need whatsoever for a power conditioner, unless you are one of the 1 person in 1000 that lives next door to a large manufacturing plant or other egregious noise source.
If you are using unbalanced in ...

1. That is obvious. Thats why I generally provide links to what is under discussion.
2. You obviously don't live in the Nasty Apple....

There is more than one way skin a cat. If fail to see the relevance of balanced interconnects in dealing with transverse mode noise on our mains. The goto man on minimization of noise and ground loops in the context of single ended interconnects is Dan Banquer -
http://www.audiocircle.com/index.php?topic=8780.msg74814#74814

If you wish to enlighten us on balanced interconnects as the solution to all, please start a new thread. Be sure to include the requisite link to Bill Whitlock's papers.

GBB · « **Reply #8 on:** 26 Apr 2006, 11:14 pm »

Occam,
I'm in the neighborhood and have some Ref 8 amps and a P8 preamp. The Ref 8s were the ones you listened to at the March Rave - they responded very well to the Adept power conditioning there.
I've listened to them with balanced power at my brother-in-laws and they sounded really good there so I'm thinking thats the way to go. I've got a big isolation transformer off of ebay that I want to try out. I need to dig into it and see if it can be rewired for balanced power or not.
I've also thought it might be worth trying some CMCs between the switching power supply and amp boards to see how that affects the sound.

Glad to experiment if you're interested.
Thanks,
---Gary

Occam · « **Reply #9 on:** 26 Apr 2006, 11:28 pm »

Gary,

Done! Your Felicias awaits. And if they're not big enough for the amps, I've at least a tonne of other transformers. Anyone who has been to Chez Occam will tell you thats not an exageration. And yes, I do have a long suffering wife. I'm sending you a PM.

Hot Damn,
Paul

Daemon · « **Reply #10 on:** 26 Apr 2006, 11:32 pm »

Actually Occam, if you could extend that invite to anyone with NuForce Reference 9 and their P8 too, I'd be greatful. I'd come and let you guinea pig mine, but with the return flight from Australia and all, I could buy one of the exhorbitant off the shelf thingumy bobs and forget the DIY bit.

Just to make sure I've got the basic concept down. The Felicia is a balanced power supply. It provides a certain amount of mains noise rejection in the same way a balanced XLR interconect does with a fully balanced pair of devices: It switches phase on one 'channel' and what isn't the same on both doesn't get passed through, then switches one back again before the electrons (which I have it on good authority, are the size of a small pea and coloured blue) disapear into the mysteries of the device you're powering? At least, that's more or less what I understand by common mode rejection, I can't tell from the circuit becuase I know squat about electronics. Is that sort of it?

THe trade off is lowering of the current that can be supplied?

How much noise does it get rid of and how much gets through?

Occam · « **Reply #11 on:** 27 Apr 2006, 01:14 am »

Hi Daemon,

(Is your first name Maxwell's?) I take it you're in the land of Ozz? Building a Felicia to power your P8 and other source components shouldn't be problematic. Suitable transformers are available from Farnell and RS, at semi reasonable prices. The Felicia uses a pair of cascaded transformers (in a configuration that I believe is still illegal in the state of Mississippi) that provides both noise attenuation and and balancing. For 'whitepapers' on the benefits of balanced (technical) power -
http://www.equitech.com/articles/articles.html
There is a 'sticky' on the Lab forum specifically about Felicia -
http://www.audiocircle.com/index.php?topic=18441
which links to a ponderous constructors thread of 30+ pages.

The increased potential power draw of the Ref 9 above that of the 8 makes building a trasformer based conditioner (whether balancing or straight isolation) less straightforward. The depth of your surplus market is not nearly as deep as in the States. Your best bet would probably buying a 'site transformer', which I occasionally see on Ebay offered from Australia (and GB as well).
http://www.airlinktransformers.com/sitetransformers.asp
Because these transformers are not made for audiophiles they're quite reasonably priced even at retail. They typically convert 240vac to 110vac to allow use of 'American' tools in 240vac countries. They've shielding between primary and secondary and with a center tapped and grounded secondary. And that is balanced (technical) power. This is not for high falutin audio reasons, but strictly for safety. The danger from human contact from their 55vac (the voltage of one of the powered legs) is nominally 1/16th that of contact with 240vac.
For NuForce components this is quite fortuitous, as they run (I believe?) from AC mains spanning 90-240vac. So now we need a non-Norte Americano as a guinea pig, who'd be willing to experiment with capacitors to augment the conditioning capabilities, measure actual balance, etc....

That'll teach you for asking

Regards,
Paul

Daemon · « **Reply #12 on:** 27 Apr 2006, 11:36 am »

From Oz it is. I don't mind what you call me, as long as I'm not mistaken for Dorothy. Actually, Daemon is my first name, but it's spelt with one of those joined ae things. Fairly obvious what that really says, so I'm guessing my mother had mixed feelings upon my arrival.

I don't know that I'd be alot of good to you for experimenting and measuring. I own no test equipment, and don't know anybody who does (though if I was going to do one of these I'd go as far as springing for a multi-meter). Worse yet, I have no understanding of electronics. I can follow a recipe but I don't really know what it is I'm doing.

I'm not too keen on making a 110v output version from site transformers, as it'd be pretty useless for anything else but the NuForce, and if I'm going to go to the effort I'd like it to be good for anything the future may hold for it. Is it possible, or perhaps practical, to build a 240v output version with enough hutspah to run a Ref 9 (which has a 350w power supply)?

Occam · « **Reply #13 on:** 4 May 2006, 02:35 pm »

Just a quick note - Gary and I spent last Sunday at Chez Occam. We learned a number of significant things. (unfortuneately, for me, it was how much my digital front end needs improvement, and that Gary's modded SB and DI/O are wonderful)

By way of background, I do live in the Nasty Apple. Specifically, Brooklyn, where the weak (both people and electrons) are killed and eaten. But my power is actually quite good, as I live in a lower density residential area, and my dedicated line runs all of 3' to my electric panel. On my own linear ps components, the impact of powerconditioning is obvious, but not 'night and day'. I've a 3 way Felica for source components and a single transformer based balanced conditioner kludged together from one of my smaller transformers @ 2kw.
The P-8 benefitted substatially (nay, demands) a Felicia or similar powerconditioner. It cleared away substantial 'mud'. Please note that evaluations of components was done with just the DUT (device under test) either into a conditioner or plugged directly into the dedicated outlet. All other components were powerconditioned.
Same goes for Gary's Nuforce amps, though the changes wrought by conditioning were not as great as with the preamp. It should also be noted that Gary felt the changes at his own exurban home were not as major.

The P8 draws all of 5watts (11va indicating a very poor power factor) and building a conditioner specifically for this trivial draw is far easier, smaller.... than a generalized powerconditioner. A Felicia is an obvious DIY choice, perhaps with smaller, easily available transformers, but because of the very small power draw, perhaps a CMC based conditioner would be easier and equally effective. Yes, I know the power input of the P8 is fed through a CMC (for FCC compliance), and NuForce maintains this is their very own built in power conditioner, but I'll simply ascribe that to marketing hyperbole. We heard what we heard......

Adamay · « **Reply #14 on:** 4 May 2006, 04:23 pm »

Thanks a bunch, Occam & Gary. Two questions: 1) Does a Felecia provide enough power for 2 Nuforce mono's (8.02's, in my case)? 2) Did you try any other power transformer (e.g., a big Powervar) to see whether it provided similar (albeit lesser) benefits? Thanks again!

GBB · « **Reply #15 on:** 4 May 2006, 09:10 pm »

Quote from: Occam

Just a quick note - Gary and I spent last Sunday at Chez Occam. We learned a number of significant things. The P-8 benefitted substatially (nay, demands) a Felicia or similar powerconditioner. It cleared away substantial 'mud'. Please note that evaluations of components was done with just the DUT (device under test) either into a conditioner or plugged directly into the dedicated outlet. All other components were powerconditioned.
Same goes for Gary's Nuforce amps, though the changes wrought by conditioning were not as great as with the preamp. It should also be noted that Gary felt the changes at his own exurban home were not as major. ...

Let me just chime in and say that Occam's AKSA components and Alon speakers were quite wonderful. We swapped in my various Nuforce components and various power conditioning but when we were done with our experiments we returned to the AKSA for musical enjoyment. I have to say that I'm a bit perplexed because I think the Nuforces sound better at my house but at two different places I've visited with the Nuforces they sounded a bit harsh and unmusical.
At Philnyc's place the addition of an Audience Adept power conditioner made them sound quite nice. Here the addition of an isolation transformer was a big improvement and I think the Felicia style conditioners were even better. But still not a match for the Aksa amps.
So I'm now pretty motivated to experiment with different power conditioners to see what it takes to smooth out the Nuforces. My pet theory is that the amps are getting noise back into the power grid and adversely affecting other components.
Occam kindly sent me home with a wide range of transformers and filters along with some good ideas so I now have a lot of homework.

For those of you with digital amps the conclusion is clear - the addition of good power conditioning is a requirement for best sound. And Occam's Felicity is a pretty good starting point although there might be some simpler options available in the future.

---Gary

Occam · « **Reply #16 on:** 4 May 2006, 10:34 pm »

Quote from: GBB

...My pet theory is that the amps are getting noise back into the power grid and adversely affecting other components....

Gary,

I'm unsure as to whether that explains what we've observed. At PhilNYC's with the Nuforce amps, and on this Sunday's with the Nuforce P-8 pre, all the other components were hooked up to conditioners that provided isolation between components. Certainly, isolation between a Nuforce XXX and other components would increase with a conditioner on that Nuforce component, but in both situations, we had initial inductive isolation via the conditioners on the other components, the Audience Adept or Felicias

Adamay,

I'm sorry, but we ran out of time last Sunday, so we didn't test a Nuforce 8 amp per Felicia. With a very simple rewiring of a Felica (with the 'standard' Signal A41-175 tranformer) it might be quite feasable. This would simply require reconfiguring the input windinds of the input transformer to parallel as opposed to series. Feeding that the same 120vac would result in producing 240vac balanced split phase power, resulting in a doubling of potential power output. As the NuForce's ps runs on 90 - 240vac it actually might be a good solution. But, without first hand experience, I'd tend to a conservative no.
Yes, there are some benefits to using a straight isolation transformer such as a OneAc or PowerVar. But the benefits have never been in the same leauge as a Felicia on source components, or an Adept on any type of component.

FWIW.
Paul