[audioferret]

Audioferret,

Thanks for the references to those interesting URLs. As Josh said, while both of those projects, like the Felicia, provide the benefits of balanced power, the 'nulling' of reactive leakage currents on the fed components (to the extent that those center tapped output windings are balanced), those projects take a different approach (and I believe, efficay) towards the power conditioning function.

As described by ThomasW, both the Transcendent balancing conditioner and his own project use Av ...

  Awesome! Thanks for helping me understand that.  I think I will go with the Felicia and give it a try.  Now that I have a better grasp on the physics, I am more comfortable with it.  (I have a Mechanical Engeneering Background...not enough EE).  
 
  I really liked the documentation on Thomas's site.  As I build the Felicia, I will try to put something together like it and submit it to your circle for comment. (It may be a few months).  Thanks for your help.  ...Now I just need to get my hands on some transformers...

[audioferret]

The Monolithic Power Supply for the P3a and P1a seems to have satisfactory filtering and power conditioning on its own...but....

Would a felicia be redundant and unneccessary?  I have currently budgeted/ordered parts for two Felicias (one for CD player, one for Pre-amp).  I will test out the Felicia in different combos and get back to you all...

Just mumbling.

"One project at a time..." - says the wife
"What exactly do you mean by that?..." I reply
-Stupid answer

[Occam]

Would a felicia be redundant and unneccessary?

Dunno. I'm casually familiar with the various Monolithic PSs, and don't know the specifics of yours.
I've not found a mains powered source component that hasn't benefitted from her alluring charms, including some that have built in filtering. If you're committed to building 2 already, test it on your monolithic kit, and see. If it provides requisite benefits, build another. Sharing a Felicia between 2 components is not ideal as a dedicated one for each, but I and others have found it to be a net gain over one filtered and one nekk'd.

[JoshK]

I think the Felicia will provide quite a step in the right direction even with adequate filtering in your PSU. Too much is never enough.  

On a side note, I have been working on rewiring my Felicia and permanently mounting three of them in my old power cond. chassis.  I plan to add some cool vintage meters for line voltage and amps drawn by the cluster.  The Felicias are definitely worth the effort IMO.

[JDUBS]

Guys

What is the construction difficulty of the Felicia relative to the BPT-type device referenced by Audioferret?

That website was pretty solid in laying out exactly what is needed and where you can get everything in addition to showing the construction step-by-step.

I'm going to have some time off for the holidays and would love to tackle something like this...but I just want to make sure I don't get in over my head.  

BTW, this would be for an SB3 and turntable.

Thanks in advance for any feedback!

-Jim

[audioferret]

I have set up a scratch web site to document the Felicia project.  I have studied this thread at length and feel this is a relativey simple project to build, so this should be quite manageable with some soldering skills and attention to detail.   My web site will mimick Thomas's balanced power sites in style.

  I should have all of my parts by next week and will knock it out over the weekend.  I will keep you informed.

[JDUBS]

Excellent!  That will be extremely helpful to a great many folks, I would imagine, Audioferret.

Good luck!!

-Jim

[JoshK]

I think one of the reasons why Occam and I haven't made this a step by step tutorial was due to safety concerns.  We figured if we basically gave you everything you need to know san the step-by-step instructions then only those with a modest amount of DIY'ing would build it, not the super-newbies.  This is because we are dealing with line voltage which can kill if someone isn't aware of what they are doing.

It is a very simple project to do, provided you can understand the wiring of the transformers.  Take some time to really sit down and try to figure out what is going on with the primary and secondaries of the tx.  This will help you understand how to avoid making a grave error.  

Paul has on numerous times, said, "try this" or "try that".  I have to draw it out.  This is because I am fair newb myself.  But it does help.

[JDUBS]

I think one of the reasons why Occam and I haven't made this a step by step tutorial was due to safety concerns.  We figured if we basically gave you everything you need to know san the step-by-step instructions then only those with a modest amount of DIY'ing would build it, not the super-newbies.  This is because we are dealing with line voltage which can kill if someone isn't aware of what they are doing.

It is a very simple project to do, provided you can understand the wiring of the transformers.  T ...

Absolutely, Josh.  For me, a picture-based walk-through would serve more as a santity check.

-Jim

[audioferret]

Well, I finally have all of the parts for my Felicia!

I will add pictures to my site this evening.  The first page will cover the parts list I am using and pictures of the inventory.

"Doing the Happy Dance...
    "Doing the Happy Dance..."
 

[JDUBS]

Well, I finally have all of the parts for my Felicia!

I will add pictures to my site this evening.  The first page will cover the parts list I am using and pictures of the inventory.

"Doing the Happy Dance...
    "Doing the Happy Dance..."
 

Awesome....can't wait audioferret!

[Occam]

1. I just got off the phone with Tammie at BGMicro about the 'slight' backorder problem with those $10 Signal A41 175va transformers. Supposedly, their supplier is working trough the mound of crap in front of the equipment housing those transformers. While I've heard that before, Tammie and Billy at BGMicro are 'stand up' folks. We shall see.

2. Audioferret is quite pleased with the results he has gotten-
http://www.geocities.com/ghaunadaur99/audio/felicia.html
with the alternative $18 transformers from MPJA -
http://www.mpja.com/directview.asp?product=7846+TR
anyone with a Signal A41 based Felicia in the Colorado Springs area that would participate in a comparison if AF is willing?

3. Folks have expressed an interest in mini-Felicias for powering things such as SB2/3 PSs and switching suppied DVD players, set top cable/satellite boxes, etc... The most appropriate transformers I've found for that application is equivalent to the VPP24-2330 Magnetec Triad from hosfelt.com for $6.49ea. I've sourced over 100 of them (Mrs. Occam is NOT pleased) as they were 'such a bargain'. I've sent out 8 of them to a fellow Circler, and will prod him for an evaluation as he has his own standard Felicias. If they work well, I can possibly get 200+ more that could be delived to builders for less than $4ea.

4. Given that multiple Felicias are large and hernia inducing, as well as having inherent problems with voltage sag, I've had some custom balancing transformers made. Ideally, these would be able to power 2-3 source components(a total of 120 watts) while providing isolation between components. But I've not yet gotten results equal to individual Felicias. If I can get the topology right (the components before and after), I'll simply give folks a link to the vendor, and start a Felicia II thread. My goal is a conditioner that is smaller, lighter, better or equal performing, and when powering multiple components, is less costly. That before and after topology will also serve as the basis for Felix, intended to power amps.

Which brings me to my own 'issues'. Development of DIY projects is best done with a Diy buddy. At some point, no matter how good my equations and measurements, the pedal hits the metal and one must subjectively evaluate their efforts. For subjective evaluations, 4 competent ears are always better than 2. But after 30 years, my wife simply ignores my requests to listen, and my sons run out of the house. I also tend to be distracted by things like bright shiny objects and kitty kats...... The major developments in the Felicia project have first been done with JoshK, and later with Tianguis. But these fellas actually have lives and other projects of their own. Soooo... I'm actually hoping to invite someone to help me, trapping him at Chez Occam over a weekend. You know who you are....

FWIW,
Occam

[Christopher Witmer]

You want me to fly all the way from Tokyo?  

[samplesj]

3. Folks have expressed an interest in mini-Felicias for powering things such as SB2/3 PSs and switching suppied DVD players, set top cable/satellite boxes, etc... The most appropriate transformers I've found for that application is equivalent to the VPP24-2330 Magnetec Triad from hosfelt.com for $6.49ea. I've sourced over 100 of them (Mrs. Occam is NOT pleased) as they were 'such a bargain'. I've sent out 8 of them to a fellow Circler, and will prod him for an evaluation as he has his own standard Felicias. If they work well, I can possibly get 200+ more that could be delived to builders for less than $4ea.

Hmmm, that looks one does look very interesting for the two I need.  I can definately take a hint since I just asked about my sb3/benchmark.  The specs on that one look like its around 29VA when balanced which gives me much more wiggle room.  

Thanks for the transformer research.  Actually thank you for all of your work on this project.  You've definately gone over and above a few extra miles with all of the extra work finding new transformers after the old ones dried up.

After I've got it up and running in a week or two I'll try to get some of the measurements to post.

[Occam]

So Christopher, when will you be flying in?   Actually, I'm quite pleased that you've actually gotten some 'World Power' type transformers. Not that some of those transformers you've already gotten aren't absolutely gorgeous. Let me know if you need some help sourcing the Jantzen and/or Auricap caps. If PE won't ship, or charges outrageously to ship to Japan, let me know.

Samples -

The problem is, the appropriate value for the for the 'bulk' betwixt and between capacitor (presently 18uf for the Signal A41s) is unknown, and it really does take some pain in the arse experimentation. A double pole, double throw switch really is needed, because aural memory really does suck. The present .47 and .1uf Jantzens shouldn't change (I hope), and the same goes for the .01 Auricap for the truly obscessive.

I'll make an offer to 3 potential builders, with the proviso that you already have a working Felicia, and a commitment to do that experimentation. I simply don't want to put a revised version mini-Felicia on this thread that isn't the equal of the present A41 based version, albeit at lower max power. So if you're interested, and up to the task, PM me.

And if the truth be told, my fondest wish is for that Felicia version II, based on that custom transformer that could support multiple source components while minimizing that voltage droop problem. The vendor who fabricated them for me is a true pleasure to deal with, and it would make everyones life so much easier. And it might save someone from a hernia  

as ever,
Paul

[mgalusha]

3. Folks have expressed an interest in mini-Felicias for powering things such as SB2/3 PSs and switching suppied DVD players, set top cable/satellite boxes, etc... The most appropriate transformers I've found for that application is equivalent to the VPP24-2330 Magnetec Triad from hosfelt.com for $6.49ea. I've sourced over 100 of them (Mrs. Occam is NOT pleased) as they were 'such a bargain'. I've sent out 8 of them to a fellow Circler, and will prod him for an evaluation as he has his own standard Felicias. If they work well, I can possibly get 200+ more that could be delived to builders for less than $4ea.

Well mine is obviously not a mini-Felicia but buiding an A41 based Felicia and the Squeezebox PS into the same chassis has worked out well. I am extremely pleased with the results. If anyone is contemplating this (mini-F for a SB), it's well worth the time and effort.

While I should post a follow up on "Felicia Squeezemore" in the original thread the short version is that it's awesome.

[randytsuch]

Well mine is obviously not a mini-Felicia but buiding an A41 based Felicia and the Squeezebox PS into the same chassis has worked out well. I am extremely pleased with the results. If anyone is contemplating this (mini-F for a SB), it's well worth the time and effort.

While I should post a follow up on "Felicia Squeezemore" in the original thread the short version is that it's awesome.

I want one  .
But, bgmicro is out of the A41.  Hope they will get some in soon.
On the positive side, I just built a "normal" linear supply for my SB3, and am happy with the outcome.

Randy

[samplesj]

The problem is, the appropriate value for the for the 'bulk' betwixt and between capacitor (presently 18uf for the Signal A41s) is unknown, and it really does take some pain in the arse experimentation. A double pole, double throw switch really is needed, because aural memory really does suck. The present .47 and .1uf Jantzens shouldn't change (I hope), and the same goes for the .01 Auricap for the truly obscessive.

Sorry I can't help with the head to head against the original Signal A41s, but I'm certainly willing to help narrow down the bulk value.  I can buy a whole lot of caps for the difference in price between parts for two Felicia and another BPT .  For finding the value do you think the brand will matter?

A 3amp 120V DPDT should be ok shouldn't it?  I've actually got an extra right on top of my parts stack.  I was going to make my TVC integrated floatable, soft, or hard grounded, but after running into some hum issues I took it out to help simplify troubleshooting.

You had mentioned earlier in the thread to Christopher that he might want to start at 15uf, but should I start even lower since this is a much smaller VA rating?

This is all just to further refine the sound right?  If I'm following the schematic right I could actually leave them out altogether and it'd still provide balanced power, but I wouldn't get the extra filtering.  I've only got one set of ears though.  I can get my wife to help a little (final touches/tweaks), but an exhaustive better worse with caps wouldn't fly.

I've got a decent meter, but if something needs to be measured on a scope its a little harder since I can't do that on the fly.

[Gordy]

Jeremy, you have a scope?     What transformers will you be using?

A 1a fast blow fuse has sufficed for the Modwright pre and the TACT pre, a 3a switch should be fine for testing, I'd presume...  I've 3 or 4 spare DPDT 25a toggles if you'd like to borrow one for a while, actually you can have one if ya promise to report back on your scope results!!!

[Occam]

Samples,

Actually, the specific bulk capacitance accross the transformers' secondaries has a critical impact on the overall 'success' of a Felicia. One would think that because this cap is bypassed by a .47 & .1uf cap (and optionally a .01uf) that is wouldn't be particularly critical. The subjectivist/mathematician in me tells me this is obviously true. But sadly, the empirical subjectivist in me and many others tells a very different story. For that range settled on for the specific Signal A41 transformer, 15-20uf, we have tried Aerovox, GE,  ASC & Amrad metallized polyprop in oil, GE foil poly in oil ($200+ retail), Solen, Aerovox, Bennic, Dayton and Jantzen dry metallized polypropolenes. Each and everyone had their own specific sonic signature. It really makes no obvious sense, as their specific characteristics and metrics did not correlate with subjective sound. They were far removed from any sonic path. They even had major effects on the subjective sound when feeding a CD transport. Any explanation I could come up with, if coming from someone else, I'd immediately charaterize as absolute horseshit. Same goes for bypass caps. The 33nf copper leaded silver mica from my secret stash that I expected to be the 'bomb' was a dud and reminded me of a ice pick driven into my eardrum. Go figure.
But luckily, the inexpensive Jantzens from PartsExpress turned out to be universally preferred and inexpensive to boot!
http://www.partsexpress.com/webpage.cfm?&DID=7&WebPage_ID=197#capacitors
I really wish they made a .01uf so I wouldn't even have to use that Auricap, which provides that last dollup of resolution. This is not to say that there aren't even better caps out there in the industrial component world or audiophilia, but I've not found them yet. And these Jantzens do satisfy my cheap SOB nature.
Yes, you can leave out the caps alltogether. You'll get balanced power and a modicum of common mode noise rejection via transformer rejection, and a schootch of differential noise rejection due to the limited capacitive coupling via split bobbin magic. But its the caps, working with the transformers that facilitate turning transverse noise into common mode noise that allow those transformers to do that voodoo that they do so well..... I'd also argue that the majority of the benefit of Felicia is powerconditioning, and balancing is that last 'icing on the cake'. One could also argue that for non mains grounded components that balancing provides no benefits whatsoever. But this really does require an analysis of the ground connections of the fed components and the components that it connects to, and how the grounds of interconnects fan out. You can experiment with this with a spst switch that leaves the output transformers center tap either grounded or floating.

Converging on the 'ideal' values and configurations for the various components is harder that one thinks in that aural memory really not as good as we think. What JoshK and I did was build 2 complete Felicias that we could rapidly switch (through actual switches) between to evaluate different caps, transformers, etc... in various roles feeding the same component. This is why I gave Gordy 8 of those 56va transformers. I've suckered   Gordy and Natureboy into doing this initial heavy lifting and am wondering whether they'll still be talking to each other after they gone though this bonding experience. When I've asked various members of the NYRave to help me optimize the custom transformer based version, for some odd reason, they run away screaming. My youngest son has chosen to visit out of town for his college break and my oldest simply has chosen to be asleep when I'm awake.

By no means do I wish to dissuade you. I, apparently unlike everyone else around me, actually enjoy the exercise. But I've been working in various lab environments since I was 19, an ideal environment for someone with less than optimal people skills. I'd suggest that you let Gordy be miserable, and when he has done the hard stuff, swoop in and grab the glory. That was the most important lesson that the 2 Nobel Laureates I've worked for have taught me.

Regards,
Paul

PS - zeroing in on capacitor values isn't that hard if you remember that caps in parallel are additive and that for caps in series -
Ctot = 1/( 1/C1 + 1/C2)
So if you have a 10uf cap and 2 5uf caps you can make 5, 10, 15 & 20uf by combinations in paralell or 2.5 uf with the 2 5s in series, or 3.33uf with a with a 10 & 5 in series....