[tianguis]

All:
      A few things I forgot to mention:
      1: The Felicia seems quieter with the transformers mounted at 90 degrees to each other.
      2: Ditto wrapping the Aerovox cans in Stillpoints ERS.
      3: Isolation makes a difference. Occam was very surprised at the improvement when the Felicia was positioned on 3 Mi-Rollers. Rollerblocks also work. I'm sure some of the spendy isolation devices would have the same effect.

Larry

[Occam]

... 3: Isolation makes a difference. Occam was very surprised at the improvement when the Felicia was positioned on 3 Mi-Rollers...

Stunned speechless. A very rare occurance for me.

[Carlman]

What kind of trafo's and caps would I need to build a Felicia-like device that supplies power to a PC (300w power supply) and a DK Integrated amp?

Am I out of the league of EI transformers this size?  Is the cost going to skyrocket to build this?

[Christopher Witmer]

"EI" is literally giving us a graphical illustration of the transformer core configuration, and EI transformers are pretty standard, regardless of how large you might go.

The general concept behind Felicia calls for a pair of transformers, but they don't have to be identical, and neither is it necessary for BOTH of them to have dual taps. The side of the transformer connecting to the equipment you're trying to protect must have dual taps if you want balanced power. The type of transformer you want to look for is one where you could input 240V and output two channels of 120V each; you will instead be inputting 120V and taking out two channels of 60V each, which are then tied together to give you 120V balanced power.

Here is an example of a transformer that looks like it could be a candidate for a large Felicia type unit:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=42881&item=7521664088

The one shown above is nominally a 3kVA transformer, but with balanced power the rating would be halved to 1.5kVA. Most integrated amplifiers and PCs could be connected to that wit room to spare.

Just a single transformer like the one shown above will give good results, but of course it wouldn't be a large Felicia unit. You would still need another transformer, but it could be a plain vanilla 1:1 isolation transformer. (It is a plus if it is shielded: key search terms are "medical transformer" "hospital transformer" etc.)

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=66995&item=7521196590
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=14968&item=5780050874

Anyway, there are plenty of candidate transformers out there, once you know what you are looking for. Then it is just a matter of what sort of budget you have. If you wait long enough, you will find a unit you can afford.

[Carlman]

Hmmm.. that Xentek looks nice... I greatly appreciate your response, Christopher.

-Carl

[JoshK]

Our initial venture into more powerful Felicias, for components like computers, plasma TVs, etc has proved fruitless, at least if lack of hum is important to you.  This doesn't mean it isn't possible to build one that doesn't hum but our experiments with readily available and inexpensive powerful trannies has given us some trouble.  The signal transformer from BG Micro is great in that it doesn't hum when configured as written.

So far the solutions derived are for more modest current draws but this still does not exclude most sources, preamps and even some more efficient or smaller powered amps like tripath amps.  The results are cummulative and profound.  Honestly in my limited experience in the audiophile realm this is one of the big discoveries, if not THE big discovery.  It just goes to show how power supply design and filtering is critical in getting the most of any circuit.

[Christopher Witmer]

I assume you are talking about acoustic hum from the transformer itself, rather than hum in the electronic signal, correct?

[JoshK]

Yes, hum from the transformers themselves.

[Stan Y]

I'm confused about whether the fuse on the input hot line should be 1A or 2A for the version of Felicia shown in the sticky post.  The instructions there mention a 1A fuse, then a 2A fuse for versions 2 and 3 (I'm guessing the 2A, but I thought I'd check before trying fuses randomly).

I have to pop the cover of my preamp to see what kind of fuse is inside of it to figure out the right value for the output lines.  Is there a generic value we can use for the output lines or does it really need to be component specific?

Thanks!  I think I've got all the parts (picked up both 1A and 2A fuses) and will be trying to put together a new Felecia later this evening!

..Stan

[Occam]

Stan,

On the outputs of Felicia, I'd go with whatever fuses are in the component is to be powered. As this is a public project, with constructors having various levels of experience, its an awkward question when someone says, 'but my component already has both lines fused and switched internally, so do I need those output fuses?'. Being a public project, my response is 'yes, as inevitably you're going to forget and use Felicia on a component that doesn't have both lines fused and switched......' So my standard response is going to be always use the same fuses on the outputs as you have in the components to be powered.
On the input of Felicia I personally use an Airpax 1amp toggle circuit breaker. (no, I don't know where you can get them on the surplus market) on the 'hot' line, the narrow blade of the plug. Cicuit breakers typically have trip characteristics similar to slo-blo fuses so they don't blow with turnon surges. The purpose of this is to provide safety for Felicia herself. If someone forgoes the output fuses/breakers and they plug in a poweramp   , or the accross the line caps short, I want the fuse/breaker to blow prior to frying the transformers.

[Stan Y]

Occam,

Thanks - I found the Tempest's fuse in a little compartment in the IEC socket.  It says it is a T4L 250V, which I believe means it's a 4A, 250V slow-blow fuse.  

Looks like I bought fast-blow fuses, so I'll have to go back to the store on Monday to get a slow blow 1A fuse for the input line on the Felecia and a couple of 4A slow blows for the output lines.  If I'm lucky, they'll have a 1A circuit breaker instead.

This isn't surplus, but is this the kind of circuit breaker that you're talking about?

http://www.newark.com/NewarkWebCommerce/newark/en_US/endecaSearch/partDetail.jsp?SKU=03C7598&N=4

I found this 3 pole, 3 toggle one at surplussales.com

https://www.surplussales.com/Electrical/ElecCirB-7-3.html

Thanks again for your help!

..Stan

[Gordy]

Hi Stan,

Mouser has better prices for switches, NKK 25a selection is here...
http://www.mouser.com/index.cfm?&handler=data.listcategory&D=*nkk*%2b*25a*%2b*toggle*%2b*switch*&Ne=300&terms=nkk+25a++toggle+switch&Ntt=*nkk*%2b*25a*%2b*toggle*%2b*switch*&Dk=1&Ns=SField&N=390&crc=false

[Stan Y]

Thanks, Gordy!

I've just downloaded the whole Mouser PDF catalog - seems like a good thing to have around.

I wonder if they can combine this with the other order I just sent them?  I'll mention it in the order comments.  

Thanks again!

[Occam]

Stan,

The 4amp fuses, whether slo blo or regular, are somewhat surprising in a preamp. I'm certainly not questioning Klaus' design decisions, but would suggest you check your manual or with Klaus. Even with 14Kuf of capacitance and a toroid transformer, 4 amps seems a bit much.
Yes, those are the airpax breakers I use, but they only cost me $1ea, but I don't know where to source any more for those prices. I'd suggest a simple 1amp slo-blo fuse on the input 'hot' line as its going to be sufficient for most any source component and keeps within the rms constraints of Felicia's transformers,

[Occam]

Stan,

And anyone else who is constructing Felicia. Before plugging any component into Felicia, you must at minimum, test the voltages!
Assuming yours terminates in a female IEC to be plugged into your component - With your meter set to at least a 150VAC scale, make sure that you read line voltage 110-130VAC (depending on your locality) accross the parallel blade openings, and half that, from each of those blade openings to the center lower ground. Unless you get thoses readings, do not plug a components in or power it with the Felicia, but post here for help in resolving the problem.

[PT914]

Hi,

Just compared the 14 uF Aerovox with a 20 uF 440VAC ASC oil filled polypropylene.   Both were bypassed with Auricaps.  Both had at least 48 hours of burn in.   My ears prefer the ASC caps.  The ASC caps were from Michael Percy Audio @ $10.95.  He mistakenly sent me the 40 uF caps which I tried and they were bad, no highs.  But the 20s are sweet.

Philip

[tianguis]

Philip:
       Interesting. What equipment are you powering with the Felicia? I'm sure the 40 uF was too big, but the 20 uF may be the ticket. What values are you bypassing with?

Regards,
Larry Welsh

[guest1632]

Stan,

The 4amp fuses, whether slo blo or regular, are somewhat surprising in a preamp. I'm certainly not questioning Klaus' design decisions, but would suggest you check your manual or with Klaus. Even with 14Kuf of capacitance and a toroid transformer, 4 amps seems a bit much.
Yes, those are the airpax breakers I use, but they only cost me $1ea, but I don't know where to source any more for those prices. I'd suggest a simple 1amp slo-blo fuse on the input 'hot' line as its going to be sufficient for most any source component and keeps within the rms constraints of Felicia's transformers,

Hey Occam, My Purist has 2 4 amp one on either side of the line. Curt says that probably a 1 or 2 amp fuse will do the job, but since this amp has the capability of drawing some current when needed, he decided to use the 4 amp type. The transformer in thisucker is big for a preamp.

Ray

[PT914]

Larry,

Three separate Felicias are powering an Orion active crossover, CD-Pro2, and an Aksa GK-1R.  I am bypassing with a .47 uF and  a .01 uF auricap as you suggested.  When I was evaluating the different caps, I had to physically switch caps so there was a time lapse but the ASC was definitely better.  I tried a 1 uF instead of the .47 uF but couldn't hear a difference in the music.  The .47 may have better imaging.  Will have to get a  DPDT switch, but right now I'm very satisfied.

Thanks for sharing,
Philip

[Occam]

PT,

Yours is exactly the sort of feedback I'd been hoping for. By reputation, the ASC (especially the Japanese produced ones), the GE 97f, and the (crafted of unobtainium) Continental aircraft caps are the top of the heap.

Larry, Josh and I have experimented with numerous caps and are in the throes of 'cap burnout' (us, not the caps!). We've also restricted ourselves to whats largely available in the surplus market. But (IMO), Felicia has proven herself to be an excellent project, not only 'for the money', but regardless of price, and therefore justify upping the ante and evaluating more bespoke and costly components. (and based upon no empirical evidence, I'd think round caps would be prefferable to oval caps...)

I'd hoped that we could find 'perfection' at 'cheap SOB' prices, but alas.... a Auricap is simply better for bypass duties than a commodity Wima MP3X2. Surprise, surprise.

Rigorously evaluating components is also costly and royal pain in the arse. Even within a given vendors line one should (with the ASCs for ex) obtain the 12.5, 15, 17.5, 20, 25uf caps, all at a single voltage rating to zero in on the ideal capacitance value for the chosen transformers. Then, upon finding that value, one should evaluate whether going up or down on voltage rating impacts the subjective qualities. And then you repeat that process for different vendors. I have to admit that my own evaluations have not been as rigorous as I'd have liked.

For anyone interested, ASC oil caps are available in a variety of values and voltages from Allied -
http://www.alliedelec.com/catalog/pf.asp?FN=1094.pdf
as wll as GE motor runs -
http://www.alliedelec.com/catalog/pf.asp?FN=1120.pdf
and they've Mallory and CDE motor caps as well!

Newark also has a better variety of GE motor caps -
http://www.newark.com/NewarkWebCommerce/newark/en_US/endecaSearch/partDetail.jsp?SKU=46F3413&N=0#
FWIW

Phillip - could you elaborate on your evaluation of the subjective differences you found between the Aerovox and ASC caps? Has it been a worthwhile project? What improvements did you find and did they vary from component to component? Have you compared Felicia to any other power conditioners and what were the differences?

Regards,
Paul