Felicia Balancing PowerConditioner Constructor's Thread

speedcenter · « **Reply #160 on:** 8 Jul 2005, 03:26 pm »

Quote from: Occam

Really? Kewl..... so I'll only need half a Felicia to power each source component? Which half?

I don't have a clue what you are talking about. I wasn't talking about your tranformer thing but what you posted on the top of the page. I see no transformers in there, just Auricaps and a few black heat-shrinked components between input and output, and those clearly are too small to be transformers.

Russtafarian · « **Reply #161 on:** 8 Jul 2005, 04:34 pm »

Since we've begun discussing Felicia alternatives for higher current components, I'm pretty impressed with the performance of these Kobiconn power filters from Mouser.

http://www.mouser.com/catalog/622/1409.pdf

I've used the 10 amp CA filters with good success on CRT TVs, RPTVs, tube power amps, and my music server PC. Using one Kobiconn for each component seams to do a good job of providing both filtering and isolation.

Felicia is clearly a superior performer within it's current limitations. But the Kobiconn filter is cost effective solution for feeding those current-hungry components.

One note of caution: When I plugged a Kobiconn into my Equitech, it tripped the circuit breaker on the Equitech. I'm not sure why, but it did. The Kobiconns worked great when plugged into a PS Audio Ultimate Outlet.

Builder Brad · « **Reply #162 on:** 9 Jul 2005, 12:49 am »

This is very interesting. I have 2 x questions..

Does anyone know of a UK based supplier of suitable signal transformers which could be used in the construction multi-felicias?

What other safety features such as Earth Leakage protection could be built into the balanced power supply?

if the Felicia project is 1/2 as good as the claims it has got to be worth a try.....

Brad

Phil Townsend · « **Reply #163 on:** 9 Jul 2005, 01:43 am »

I have installed slo blo fuses on the primary and the two secondary ponts.
I had installed fast fuses before (regular standard types) The slo blo types have a bit of resistance... ( .8 ohms each) Funny thing is I think the Felicia sounds a tad better!
I'm I on drugs?
Phil
Santa Fe

JoshK · « **Reply #164 on:** 9 Jul 2005, 02:13 am »

Brad, do you have any surplus electronics sites for the UK? I'd check those first, chances are you do. I know Paul helped Christopher check for suitability of local trannies.

Builder Brad · « **Reply #165 on:** 9 Jul 2005, 11:39 pm »

Josh,

I am not sure about the surplus option - I have tried to obtain EI and C core types recently and really strugled. It seems that most of the surplus transformers are recycled for theier raw materials in the UK

Brad

Occam · « **Reply #166 on:** 11 Jul 2005, 02:09 am »

Brad - I'm unsure what you mean by multi-Felicias....
The least expensive possibly suitable transformer I've found is the Clairtronic @ JPR -
http://www.jprelec.co.uk/
For 10.95GBP each, for a dual 120v primary/ dual 20v secondary 100va they seem like they might be appropriate.

If by multi-Felicias you mean a single transformer feeding multiple output transformers, the following might be appropriate -
http://uk.farnell.com/jsp/endecaSearch/searchPage2.jsp?Ntk=&comSearch=true&select2=207758¶mSelectCount=5&showImages=true&st=parametricSelection&N=1004683+401&Ntt=&comSearch=true¶mSearch=true&st=parametricSelection&x=24&y=10

and for output -
http://uk.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=3304644&N=401
These would also be very appropriate for the input transformer for a single, Felicia. But its double the price of the Clairtronic from JPR.

These transformers offer tremendous flexibility to adjust the output voltage over a range, and would address some of the limitations of transformers connected secondary to secondary. I'll address this in a follow up post.

The galvanic isolation provided by Felicia , circumvents the proper operation of any ground fault interrupter that feeds it. For proper operation, a GFI would have to be on the output of a Felicia.

Occam · « **Reply #167 on:** 11 Jul 2005, 03:44 pm »

On the nature of Felicia and transformers in general -

I've just completed a number of measurements on Felicia which consisted of loading her with a number of different resistive loads and measuring the output voltages. Here are the results -

Input Voltage 124vAC

Output voltage vs. Load
No Load - 124vAC
40watts - 112vAC
60watts - 109vAC
100watts - 99vAC

This should not be surprising given that the specific transformers used have a reported 'regulation' of 8%. Transformer regulation is defined as-
R% = 100 x (V@nl - V@rl) / (V@rl)
wher nl is no load, and rl is rated load. Two of these transformers in series would be expected (not even looking at the fact that one is running arse backwards) of about 17%, 100 x [( 1.08 x 1.08 ) - 1]

and what do these results mean?
1. Certain components that shut down at a given low voltage condition may do so depending on its power draw. Russ has commented that a Audio Research preamp did exactly that.
2. Felicia is intended for source components as they tend to run at a constant power draw, in class A. [As her output voltage is load dependent, using slo-blo fuses with higher resistance than quick-blo, could slightly change the operating point of the fed component. This could have a positive, or negative effect depending of the specific component fed.] She also can run some low powered Class A power amps, such as the Baby Sophia and the Darling tube amps.
3. Felicia also powers the Teac tripath amps quite well. Its switching powersupply is self regulating, so it deals quite well with potentially varying (with output demand) line voltages.

So whats a fella to do????
1. Use larger transformers, which, all things being equal, have better voltage regulation. But this sort of defeats the cheap SOB approach.
2. Use transformers with taps that allow small adjustment of voltages that would allow customization of output specific to the load of the component being fed. But these transformers are obviously more expensive than the surplus Signal A41s.
3. Do 2 above, specific for the fed component, by unwinding a few turns from the secondary of the output transformer. With the secondary (used as the primary in the output transformer) at a lower voltage, it would raise the output voltage of Felicia and possibly address the shutdown issue.

Or simply accept the fact that certain components that draw power at the upper range of her intended use simply will not function with Felicia. Russ's friends AR pre is an example, but I'll point out that Felicia played quite well with a CAT SL-1 Signature pre.... It simply depends on the specific component.

Builder Brad · « **Reply #168 on:** 14 Jul 2005, 07:27 pm »

Occam/Paul

thank you for the guidance. I am about to order a number of frame mount transformers to use in a couple of low power AKSA power amps and thought that I would get the transformers for my next project - Felicia, at the same time.

I am looking to build 5 individual units using 12 transformers to power the following pieces of kit:

1)AKSA GK-1R
2)Pioneer DV868 Avi DVD player - label on back states 19watts power
3)Xbox
4)Pioneer PDP R04E plasma control box - label states 38 watts
5)Sky+ satellite reciever - this unit includes a hdd for record and playback. the label says 240 volys @ 1/2 amp, although this is certainly more for safety fuse purposes.
6)Arcam Alpha8SE

I was initially going to order 10 x 200va units with 2 x 50 volt 2ndarys from rs components, and then I saw the price. In the spirit of felicia I really would like to match the transformers to each piece of kit, and keep the cost to a minimum, do you have any ideas?

I thought that maybe i should order 2 x 200va units and build one felicia from which I can run each piece of kit and make my observations/ measurements before going any further. Or should i order transformers with lower voltage secondaries ie 25 volts@75VA and try this first.

The Rs components part numbers are 805-495 (200VA 2 x 50 volt), 805-273 (75VA 2 x 25 volt)

Occam · « **Reply #169 on:** 14 Jul 2005, 09:35 pm »

Brad,

While I appreciate your enthusiasm and desire to build 5 Felicias in one fell swoop, I would urge a more conservative approach. Please order 2 100va transformers, appropriately configured. Build a single Felicia, and make sure they work to your satisfaction prior to committing both monetarily and time wise. We've over 3,000 miles apart, which would make it rather difficult for you to display disappointment by smacking me upside the head......

Firstly, these 2 RS sourced transformers are not appropriate for balancing purposes. Their primaries are a single 230v winding, which would preclude you from grounding the output transformer primary's center tap to provide balanced operation, as these transformer only have a single 230v winding and hence, no center tap. For balanced operation, you need a transformer (at least in the output position) whose primaries are dual 115v windings, configured in series for 230v operation, where you would ground the point where those primaries connect, the center tap. You could use a single primary 230v transformer, with the same secondaries, for the input transformer, but the output transformer must have an available center tap.

RS does stock appropriate transformers; the ones specifically described as -
"Chassis Mount Clamp & Frame Construction 115/230V ac Primary Transformer - 100VA"
This is an error as what is listed is a range of transformers in various VA ratings. Their 231-8397 100va dual 24v secondary transformer would be appropriate, but its cost 15.90GBP each in quantities under 15. Their next size down is 50va and although half the price, I don't think it has adequate iron for the task.

Please consider the Clairtronic transformer I previously referenced in a previous post - http://www.jprelec.co.uk/ and from advanced seach enter '835-175' as the part # search. You'll find a perfectly lovely dual 120v primary, dual 20v secondary 100va split bobbin transformer that should work quite well, actually better than the surplus transformers we're using here in the States, as they'll offer better regulation and not require downrating. And they're only 11GBP as opposed the roughly equivalent 16GBP from RS. If you've issues with JPR you can source them from Rapid for more, or get Dagnall equivalents from Farnell.

Whichever of those transformers you source, you'd just configure them with all windings in series, just like in the Felicia 'sticky' thread -
http://www.audiocircle.com/index.php?topic=18441

You don't need the X2 cap at the input, and you can use a audio type metalized polyporpolene, Solen (aka SCR,Axon), Audyn, Mundorf, etc... 200v-630v as the betwixt and between cap, as you'd be subjecting them to only 40vAC. I don't know what would be the appropriate value for that cap, but would imagine somewhere between 7-25uf. You'll have to experiment. [Edit - I forgot to mention your locally produced ICW 250v PX series]

This should work quite well on all the components you listed, save for the 'sky+satellite reciever' whose power requirements are questionable, though you might find it works quite well with the 100va rated transformers.

Start small with one Felicia. Make sure it works and optimize. Only then should you consider building multiple units.
FWIW

Regards,
Paul

Christopher Witmer · « **Reply #170 on:** 15 Jul 2005, 02:23 pm »

Brad,

I have seen Signal transformers almost identical to the ones used in the Felicia sold on ebay in the UK. The price was cheaper than the price available in the USA. I chose not to buy them because I am outside the UK and international postage from the UK is about three times the cost of postage from the USA. But since you are in the UK they would be a great bargain if they are still on ebay.

Russtafarian · « **Reply #171 on:** 15 Jul 2005, 11:12 pm »

Last year before the Tripath craze became the Hypex craze, I built a six channel Tripath amp based on the TK2150 chipset which kicks out about 100 wpc into 8 ohms. It worked, and sounded really good through most of the frequency range. But the highs just never sounded right to me. There was a layer of grain and glare in the sound of the amp that just drove me crazy. I reworked the power supply a couple times, spending way too much money on exotic filtering and bypass caps. I finally gave up and relegated the amp to surround sound and subwoofer duty, which it handled quite well.

Since it has been driving a pair of highly eq’d dipole subs, I recently decided to beef up the power transformer and filter caps, effectively doubling the VA current rating and filter capacitance (thanks again for your help with this Paul). This helped but didn’t fix the sound of the high frequencies.

While inside the amp I spied the little regulated 5V supply that powers the TC2001 digital switcher chip that feeds the TK2150. I had parallel wired the 5V supply to the AC line for the power amp PS. What if I powered that discretely from a Felicia? So I ran a separate ungrounded power cable to the 5V supply and plugged it into the Franken-Felicia.

That made a big difference. The amp is really musical now! I can now hear why others really like the Tripath sound. In addition to low-end authority and midrange resolution and openness, the highs are now clear, clean and extended rather than edgy and gritty. Moving the 5V power plug back and forth between the Felicia and an unfiltered outlet clearly demonstrates that cleaning up the power to the TC2001 chip makes all the difference in the sound of this amp.

Another Felicia success story!

tianguis · « **Reply #172 on:** 16 Jul 2005, 12:40 am »

Russ:
Yup, that's one of the reasons I keep pursuing Felicia tweaks. I've been running a modded T-Amp for some time. Recently, I started modding a Teac A-L700P. Out of the box, on raw AC mains, lots of grit on top. The Felicia turned it into a very listenable amp, very similar to my SLA powered T-Amp. I have a way to go before the Teac reaches the performance of the T-Amp, but I know what you've experienced with the Felicia.

Regards,
Larry Welsh

Occam · « **Reply #173 on:** 16 Jul 2005, 02:10 am »

Russ,

Thanks for the post. You made my day. I laughed so hard that I almost pissed m'self. Its a fabulous idea on your part, but the thought of a 14+lb Felicia powering a 5v supply with a max draw of 180ma (<1 watt) struck me as incredibly funny. But I can't figure out a less costly way of achieving those benefits.
I recently made a foray onto another board and commented on the benefits 'throwing iron' at an ac supply, and was assured the modern regulators would obviate the need for such.

Its painful to see the ideal shown as a toroid transformer feeding a bridge and multi ic regulator. Its sorta like those old cartoons where the protagonist would drill a hole in the bottom of the boat to let out the leaking water....
You could use a 6v sla and use a ic or discrete regulator to get your 5v, but you'll need a chrager....

What sort of 5v supply are you using? It is a linear regulator, I assume?

Thanks again. You really did make my day.

-Paul

JoshK · « **Reply #174 on:** 16 Jul 2005, 08:20 pm »

Holy mother of eecha-cola-chiech!

I just flung together a Felicia using older caps in series configuration and if I told you how much it improved things just on my DEQX you wouldn't believe me!

Trouble with my system these days is I changed virtually everything at once. Totally wrong way about it but only practical way I could do all that I needed to do without taking a year to do it. My system the last week has basically been barely listenable as a result. I still needed to work out quite a few elements to settle it in, but it was basically running in current form.

The system that we had initially tested our Felicia experiment is no longer at my home. The system I have now is using my Sony XA777ES as a transport > DEQX (full range, no correction) > UcD 400 (my bass amp), and my newly modded RM40s that have some work to be done to tune them correctly still but are in the ball park. My UcD400 is using the most basic of PSUs in it in order for me to get it up and running and trying things out. However, it is oscillating at high frequencies resulting in a very high pitch but almost inaudible high freq hum coming out my speakers. At first I thought this was the DEQX but I think it is the bridge rectifiers in my UcD 400 needing some bypassing and high freq filtering.

My system was loud and clear for the most part but all the magic was most definitely gone and music wasn't terribly enjoyable to listen to lately. The Felicia made my system listenable only on the DEQX, and in no where near present SOTA form.

Russtafarian · « **Reply #175 on:** 17 Jul 2005, 04:08 am »

Quote

What sort of 5v supply are you using? It is a linear regulator, I assume?

Yup, 9vac toroid, hexfred bridge recitifier, 7805 regulator, electrolytic caps.

I'm just stunned at the change. I went from resenting this amp for taking so much of my time and money and sounding like crap, to really liking it now.

nature boy · « **Reply #176 on:** 17 Jul 2005, 09:48 pm »

Paul and Josh,

Thanks to Gordy

, I had the opportunity to listen to his DIY "Felicia" balanced power conditioner in my system this afternoon. Due to the configuration and his dedicated lines out, we could only hook-up my preamp and SACD/CDP (my turntable and phono preamp were a no go because they lack IEC's).

Anyhow, a real noticeable improvement. Lower noise floor, music was very dynamic, much better spatial placement of images. I am now a beliver and with Gordy's help will be trying to put one of these together if I can get my hands on some transformers later this summer.

Thanks for bringing this very inexpensive power cleaner to the attention of Audio Circle members. It's a real winner IMHO.

Now to find a nice box that will fit 6 of those beefy, heavy transformers.

NB

Gordy · « **Reply #177 on:** 18 Jul 2005, 01:01 am »

Thank you for the vinyl fix Roger!

Looks like we have another convert, though you had me worried there for a bit... your total silence was killing me

When you finally uttered, "Well you learn something new every day, I didn't think power conditioning could do so much" it was a huge relief!!! Glad you enjoyed, now if only those backordered transformers would come in... and I could remember to bring the iec adapters

What I brought over to Roger's was a Felicia two pack using the aerovox caps bypassed with auricaps (.47, .1 and .01). Nothing across the input or output as yet... a Hubble/VHAudio twisted pair power input and captive volex output cords.

RonR · « **Reply #178 on:** 20 Jul 2005, 01:24 pm »

Hi Paul and Felicia-lovers,

I finally found the time to complete the 240V Felicia. Mains cables in & out are hard-wired Chris VenHaus cryo'd Flavor 2, as is all internal cabling. The 50V secondaries are wired in parallel at the moment, and I'll be burning it in for quite a while if I can resist using it in my system!
I'm using a 0.47 Auricap that I had lying around as bypass at the moment, and I have a question before I order the 'real' bypass caps:

To get the best from Felicia, do the three auricaps all have to be the same Voltage rating? (I think I've seen them at 450V, 600V and 1500V ratings)

Cheers,

Ron.

Phil Townsend · « **Reply #179 on:** 20 Jul 2005, 01:40 pm »

I do not think it matters.
I have not been able to HEAR any changes as a result of voltage differences.
Also FYI... I placed my 3 Felicias into service right after building them. If they required a burn in period I did not notice. Seemed to work perfectly right out of the box.

Enjoy our tunes