Felicia Balanced Power Conditioner Website

Status
Not open for further replies.
Jump to Latest
A

audioferret

Member
Joined 2005
#1
I am constructing the Felicia described and outlined in Audiocircle.com under "The Lab". The project was designed and tested by Occam and others.

http://www.audiocircle.com/circles/viewtopic.php?t=18441

I noticed a need for more detailed construction plans, so I am building a website dedicated to the project. Hopefully, it will help others.

You can follow my progress at:

http://www.geocities.com/ghaunadaur99/audio/felicia.html
and
http://www.geocities.com/ghaunadaur99/audio/felicia2.html

I will clean up the website after I finish the project, but will add pages as I complete each stage.

Enjoy! (And stop me if I am doing something that will electrocute myself!)
 
#3
Hi,
I have had a look at the audio circle link.
Why are the two 110Vac primaries connected in series from the 110Vac mains outlet?

Would it be easier to connect a 110Vac primary to 110Vac mains outlet?

I can see that the second transformer needs dual primaries to form the balanced output.

What is the purpose of reducing the intermediate coupling stage down to 12Vac? You are using 400V caps.
 
#5
Web Site Draft Completed!

I have finished the project and posted my results to my web page. :smash:

Now, I need to refine it. I have a list of comments from Occam that I need to add (such as crediting the original designer, John Rish). I also need to add an index page overview and a pictoral parts list. Last, I will add navigation buttons to make surfing easier. For now, just change the number after 'felicia' from 1-8 in your HTML browser.

I need input from other readers as well, particularly ones who are not familiar with this kind of project. While this is not a project for the uninitiated, this is something that can be pretty tricky. (I learned the hard way)

As time goes by, I hope this web site serves as a good reference to help others.

http://www.geocities.com/ghaunadaur99/audio/felicia4.html
http://www.geocities.com/ghaunadaur99/audio/felicia5.html
http://www.geocities.com/ghaunadaur99/audio/felicia6.html
http://www.geocities.com/ghaunadaur99/audio/felicia7.html
http://www.geocities.com/ghaunadaur99/audio/felicia8.html
 
#7
ctviggen said:
You could probably use voltages other than 12V. A 10:1 transformer is probably just easy to find and relatively inexpensive. The idea is to get rid of common mode noise.
Click to expand...
Absolutely! The higher the voltage on the secondaries, the lower (all things being equal) the losses. The choices of the transformers was dictated by the availability of inexpensive, surplus, dual bobbin transformers. Dual bobbin transformers were chosen for their low bandwidth and minimal capacitive coupling between primary and secondary. Originally, 175va Signal A41 transformers were specified as they were available from BGMicro for $10ea. When they became unobtainium, the more expensive transformers from MPJA were suggested.
The purpose of those caps accross the transformers secondaries is to convert differential (transverse) noise to common mode allowing the transformer windings to do that vodoo that they do so well.... quashing common mode noise The split phase(balanced) output facilitates the cancellation of chassis reactive leakage currents.

Bob - I saw your comment that your betrothed actually participated in your subjective evaluations. She is definately a keeper. My wife refused any more involvement 20yrs ago.

Andrew - The input transformer doesn't require a dual primary as you've pointed out. But the benefit is only having to source one type of transformer and that if you feed it 220-240vac, you'll get the same at the output, balanced, without any changes to the schematic or wiring.

Audioferret - Very, very nice. I wish my Felicias looked as nice. Howzabout some some subjective comments on the changes wrought? (if such things are allowed here on DiyAudio)

Regards,
Paul (aka Occam)
 
#8
Thanks!

Paul,

Thanks for the detailed explanation. I will cite you on the website to help more advanced folks know what is going on. The specifics of how the conditioner works is still beyond my ability to explain.

The conditioner sounds excellent. My wife is a trained voice actress with 20 years experience in musical theatre, recording, and performing. She finally sat down just to listen to music...something I have not been able to do until now.
I played a few of her favorite recordings and she was really struck by the quality of the sound. She said that when she sang along, the resonances with her voice and the music really made her feel like she was singing WITH the artist.

For me, the conditioner has really brought my system to a point where I finally feel like the artists are in my house. The sense of THERENESS has really stood up. That is the best way that I can explain it without going into the thunderous lows, creamy mids, and velvety soft highs. Music has definitely improved.

This also made a nice impact on picture quality by feeding my DVD player and VCR. Noise was reduced, resulting in a clearer, less grainy image. Blacks were definitely blacker, particularly the bars at the top and bottom of widescreen presentations.

In my short, objective opinion, this thing ROCKS!:smash:
 
#11
I am impressed! Nice work. I would like to point out one thing.

There should be a seperate earth wire from the one you are using. This won't affect the sound or usability. It's a safety issue. Assume you place a GFI outlet on your wall and you plug this box into it. There is a potential for leakage currents from the center tap to trip the GFI. The earth you have now acts kinda like a neutral, not a earth. Earth is to be completely seperate from any other wiring and be used for a safety path of current and nothing else.

Sorry, not trying to rain on your parade.
Mike
 
#12
I'm not sure I understand

Thanks Mike, but how would I connect the earth wire?😕

I have all of the ground wires going to the same point; and from that point, I have a wire running to the ground input of the IEC. How should I connect this differently? Do I need to add an extra wire and where should I connect it? My electronics background is admittably weak.

Thanks again, 🙂
-Will
 
#15
Hi Mike,

Rain is a good thing....🙂 Your concern is quite valid, but not for the reason that a balancing transformer with cause a GFI fault, actually quite the opposite; a GFI typically does not trip when feeding a balancing transfomer, even when the components fed by a balancing transformer experience a ground fault.

It helps to examine a typical GFI circuit -
http://www.national.com/pf/LM/LM1851.html
If you look at Fig 2 of the typical application circuit in the PDF, you'll see that the principal of operation is that if what goes in does not equal what comes out, you've got a leak.
Its implemented with a differential transformer, with three windings, 2 equal which carry the 'hot' and 'neutral' lines antiphase, and a sense coil. If the 2 equal windings are not carrying equal currents, they don't cancel, and the sense coil picks this up and trips the fault disconnect. A typical GFI does not monitor the safety ground at all; otherwise they wouldn't work with 2 pronged appliances such as hairdryers :bigeyes:

The output of a balancing transformer, either a cascade circuit such as Felicia or a single transformer, is galvanically isolated from the input. The only way a GFI feeding a balancing transformer will trip is if there is a fault in the input primary winding of the transformer; faults in the fed components will not be seen by the GFI.
 
#16
Ozone,

An ideal transformer for Felicia transformers, sourced from Digikey would be -
http://rocky.digikey.com/scripts/ProductInfo.dll?Site=US&V=237&M=VPS36-4800
This Triad transformer is a 'World Power' split bobbin 175va just like the projects originally specified Signal A41 save for the fact it has dual 18v secondaries rather than 14v secondaries of that (currently unobtainium) surplus transformer from BGMicro. The higher secondary would give slightly lower losses.
But at $41ea as opposed to the $10 surplus A41 from BGMicro, or the $18 trans from MPJA, it offends my cheap SOB sensibilities.
Hammond, a Canadian manufacturer, makes an equivalent 'World Power' series, with their 185G36 being exactly equivalent to the Digikey sourced VPS36-4800. Their 185G28 is equivalent to the BGMicro's surplus Signal A41. Partsconnexion carries those Hammonds at a slightly lower price than Digikey. Sayal.com in Toronto has 2 185G24 in stock and you could get a quote from them.
 
#18
CD Player Sized Traffos for Cheap?

I came across these on eBay the other day:

Signal A41-43-24

I picked a few up to see if I could make a cheap Felicia for my CDP.

My CDP consumes only 20W, so I hope these'll do it.

Does anybody know whether split bobbin / dual primary trafos are available in higher outputs? i.e. can you get them with output higher than 175 VA?

I would like to use some clean balance power for my Marantz which currently is rated at 450W consumption.

Thanks. 🙂
 
#20
As of this writing, NEW (not pulled) Signal A41-175-28 transformers ideal for this application are being offered by Sarah Pritchard in Tucson Arizona for $5.50 each plus freight.

Sarah Pritchard's email:

sarah_8151 [at] yahoo [dot] com

You can check her feedback:
http://myworld.ebay.com/sarahp2768

As of this writing, she has about 60 units available. At these prices for brand new, unused trannies, I expect they'll move quickly.

I have no connection with Sarah.

-- Chris
 
Status
Not open for further replies.
Top Bottom