[Occam]

Ulas,

Dunno what happened to your posts, but I'd like to thank you for that excellent point you made about 'downstream' GFCIs not being applicable to balancing transformers. As you said, whatever leakage is NOT going to be seen by a downstream GFCI (either whole house or an GFCI outlet feeding the unit). It will not be effective specifically because the transformer galvanically isolates its balanced output lines from the non balanced feeding lines. I hadn't realized that this isolation which aids in noise filtering, the cap between secondaries, also precludes the use of downstream GFCIs. Similarly, its important that you noted that even if the GFCI is properly positioned at the output of the balancing conditioner, it must be specified to trip appropriately for either the 'hot' or 'neutral' legs as they are both now live.

While we might disagree on the purpose and efficacy of fusing, your constructive commets are much appreciated.

Regards,
Paul

[Occam]

Some pictures of my Felicia Balancing Power Conditioner


Note the fine fitting of the strain reliefs for the 2 cords terminated in IECs. On the other side is a single guillotined Volex terminated in a wall plug. Nothing like a 25/64's drill bit.... perfect for jamming a Volex cord through relatively easily, while leaving a very snug fit.



Note the Nautical theme. I find this conditioner works best while playing sea shantys.



The innards. Note the use of nothing but the highest quality audiophile quick connects and wire nuts.

[andyr]

An inspired contribution to the 'dirty mains' problem!!

Congratulations, Paul and Josh....... :noteworthy:
 
Cheers,

Hugh

Hi, Hugh,

Would a 240v "Felicia" be a good idea, then, for a GK-1 in Oz?  

Regards,

Andy

[andyr]

Ohenry - The reason for suggesting a GFI (GFCI?) has to do with the nature of most of our components. Typically,  ...

Hi Paul,

Can you tell me wot a GFI/GFCI is?

Thanks,

Andy

[Occam]

Andy -

This reference appears to explain the functioning of GFCIs quite well -
http://www.codecheck.com/gfci_principal.htm

You might have noticed that I've removed suggestions as to how to use GFCIs for this application, and and instead insisted on fusing all hot lines. This is not because I think them a bad idea, but because I lack the hands on experience to confidantly advise.....

I hope someone from downunder can comment on their actual experience with balanced power on their audio. I have compared the same component conditioners here, where the only difference what changing from isolation to balanced and found it a substantial improvement.  But with the electrons spinning the wrong way where you are and all, dunno....

[Super-Gonzo]

Some pictures of a dual isolated ouput Felicia Balancing Power Conditioner

I'm rather interested in building a quad isolated version... would anyone be willing to explain or draw that circuit? I can't quite make it out from the pictures.

[Occam]

Gonzo,

Further experimentation has prompted me to give up on the dual output version of the Felicia shown in the above pictures. The savingings of 1 transformer over the 4 required in 2 separate, single output Felicias, $9, simply is not worth the compromise in performance.
So for a 4 output (90watt max power draw each, with the suggested transformers from BGMicro), you'd simply purchase 8 transformers, and build 4 separate balancing conditioners, They could share a common housing and input powercord (and common star-ground), but for optimal performance, you really want 2 transformers per source component supplied, as shown in the 'sticky' thread.
I've had some discussions with the nice folks at BG, and they're now shipping up to 4 of the transformers, plus smaller doodads in a single $8 priority airmail package. It saves substantially over UPS, arrives within 2-3 days, and the look of joy on your mail carrier's face when they deliver a 7x11x6" package weighing over 25lbs is an added bonus.

[Super-Gonzo]

Further experimentation has prompted me...

Thanks, I'll give that a shot!

[Occam]

Gonzo - actually, thank you..... I've been talking to the folks at BgMicro, and they have reported a radical increase in sales of those transformers since this threads opening, all of about 40. I'd fantisized the efforts of Josh and myself would result in hundreds being sold....

Gonzo, and all the rest of you risk takers, would you please, please post your evaluation of the this project? The good, the bad, and the ugly.
We need some feedback.

TIA,
Paul

[PT914]

Just finished a "Felicia" with single output to an active crossover.  Sure made a big difference in clarity in high treble.  Was listening to Rutter's Requiem and other sacred music, first time I could turn up the volume to get a realistic sound of choir and organ.  Didn't realize how difficult track 9 Anthem for double choir was... acapalla...they must have perfect pitch.  Anyway, it was good.  Now to build a ganged "Felicia" with four trans, my CD and pre amp have 2 amp fuses.  Can I parallel the output just like the ganged out diagram?

Thanks,
Philip

[Occam]

Phillip,

You might have noticed I pulled the dual output and ganged versions of the Felicia from the sticky thread. The single output dual transformer version appears to work substantially better.
You didn't mention which source components you plan on powering, but given my experience, I strongly reccomend an individual Felicia for each source component, and while I realize its a pain in the arse, it does eliminate interference and interactions betwixt and between. I don't forsee any problems powering your GK-1 with a Felicia with the currently reccomended transformers (I'm awaiting my own GK-1). While Hugh might specify 2amp fuses, I don't see how it could tax the (even downrated) capabilities of those transformers. That limitation of 90watts is for continuous RMS draw, not peak, and the real limitation is that the draw not raise their temperature to 'to hot to touch', about 130F.
The design itself is not current constrained; the constraint is finding NOS transformers with appropriate technical specs (either multi bobbin or interwinding shielded) that are inexpensive enough to satisfy my cheap SOB sensibilities.
Could you post what components your planning on powering?

Thanks for being the first to announce that you've actually built the dang thing and for posting your impressions.

Regards,
Paul

[PT914]

Hi Paul,

Yes I am planning to power the GK-1 and a CD-Pro2.  Thanks for the info about power draw, so I can build singles for both.
Have to play around with grounding, have a slight increase in hum in speakers.  Thanks for sharing this project with everyone, excellent results!

Philip

[lonewolfny42]

I got to try Paul and Josh's Felicia conditioner today in my three systems. With each use, you could hear a difference...and for the better !!! Thank you Paul !!! The Felicia will be at my Rave next Saturday....then a few other's can get a listen...and hear it for themselves. I think you'll like what you hear.....

[Daniel]

Chris is right.  The improvement is startling.  I had NO idea!  Big congrats to Paul and Josh.  That thing is a home run, the kind where you just drop the bat and stand there while it sails into the second deck.  Incredible.

[JoshK]

Thanks for the feedback.  That is the thing with projects like these, you never know if it is just another audiophile tweak or whether it is more profound until you build it and listen for yourself.  Paul really had some brilliant ideas that took this little project from good to quite astounishing IMHO.  I don't want to build it up too much though and pre-bias people's opinions until they get to hear it for themselves at the Rave.

[Christopher Witmer]

I wonder if the Signal Transformer A41-43-24 units at http://www.alltronics.com/transformers.htm ($4.95) would be good for DIY balanced power . . .

[ctviggen]

I'm going to have to look into building a few of these (for my preamp and transport).  They don't look too hard to build, so the only thing holding me up is lack of time.

[Occam]

Christopher,

Welcome to AudioCircles!
Both transformers, the one you referenced from alltronics, and the one reccommended on the first page of this thread from BGmicro are Signal A41 dual bobbin series, at $5 and $8 respectively. The differences are the Alltronics one is a 43va, 24volt secondary and the BG is a 175va with a 28v secondary. With the series connection required for balanced use, both must be downrated by 50%, giving a max rms use of 21.5va and 87.5va respectively, as well better regulation with the larger and less losses with the higher secondary voltage. Given that the difference in cost between the 2 required for balanced use totals $6, I see no technical reasons for choosing the less expensive of the 2.

That being said. I've not evaluated the Alltronics transformer and it might well provide subjective advantages, dunno. (Josh and I have evaluated about 7 different transformers, and feel the BGMicro transformers provide the best combination of value and availablility).

As said previously, the presently recommended components are not definitive, but simply represent, in Josh and my opinions, excellent perfomance at the cost of a single bespoke RCA plug. I encourage folks to experiment with different transformers and capacitors, but would also recommend building one using these currently 'standardized components', at least to have something to compare to.

Among the transformers we've evaluated are  -
100va r-cores, I bought the last 2, great isolation performance, but no center taps for balancing.

72va 'flatpacks'  multiple bobbins, we bought the last 5, low external field due to additional external copper shielding, and great perfomance. I'd sell my eldest to find more. I just got a quote of $60 each to have them built.

But even though these transformers had demonstrable advantages over the currently recommended trannys, Josh and I found their performance converged once one found the optimal capacitance for filtering....

[Occam]

I've been pondering how to house multiple 'Felicia's. I don't have access to a metal shop, but I do have a drill. So I searched the web for 'wooden box'. My constraints are -
1. I'm a cheap SOB.
2. I wanted a wooden box with walls thick enough that I could use a simple hole to grip my favorite Volex cords without needing addition cord retaining hardware.
3. I decided I might splurge and actually fit IECs and outlets, so I wanted to be able to do this with the indulgent expenditure of a roto-zip tool.
4. I wanted to be able to house at leat 3 separate Felicias, meaning 6 transformers, 3 caps, 7 fuses and possibly even larger transformers.

So here is what I found at Ikea among Shoddy, Krappy, etc... I also found Kartotek -
http://www.ikea.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10101&storeId=12&productId=33874&langId=-1&parentCats=10115*10298
So I bought 3 of the small versions, @$15ea. Here are some pics with transformers inside -


and here is a picture with the lid on. I plan on using the lid upside down as the bevel seems to go better that way. One of the alignments strips is already removed. I plan on drilling ventilation holes as well as holes to afix the lid with screws.


Sound like a plan?

[jdybnis]

But even though these transformers had demonstrable advantages over the currently recommended trannys, Josh and I found their performance converged once one found the optimal capacitance for filtering....

Isn't more capacitance always better (up until you start rolling off the 60Hz signal)? What is your criteria for optimal?