[Occam]

Brad,

This is most gratifying news. Congratulations and thanks for sharing your experience with the Board.
A couple of comments -

1. I don't think you've yet found the optimal 'betwixt and between' value(s) for those capacitors accross the seondary. From my experiments with a similar 100VA transformer with 36v secondaries (similar to your 40v secondaries), I'd think you'll ultimately end up with 12-20uf in capacitance between those secondaries. You've tremendous flexibility in choosing what caps you use in that low voltage environment. The MKP1837 caps from RS, in .1 & .01uf might make excellent bypass caps. You can get my favorite Jantzens (up to 50uf) in Europe. And you do have easier access of various European industrial metallized polyprop caps like the Arcotronics, Wima and EvoxRifa. The Rifa PHE 450 are available in many values and voltage ratings.

2. While I strongly believe that accross the line caps at the output of Felicia offer substantial, additional benefits, the output voltage of 200VAC+ does raise safety concerns. You do have various high quality 'X' rated caps available, such as the Evox MP3 and Wima PME271 metallied paper (best in 15mm and less lead spacing) which are rated for accross the line use at your line voltages. Similarly, RS and Farnell cary other X rated, and non-X rated caps that have sufficient AC voltage ratings, like the Rifa PHE850 and Arcotronics R76. But please, any non-X rated caps used accross full mains voltages MUST have those fuses on both output lines preceeding the caps as shown in the Felicia 'sticky'. I've mentioned these specific caps that I'm familiar with, but that list is by no means exhaustive.

I'd like to ask you to do some measurements if you would be amenable. Would you measure the input voltage to Felicia as well as the output voltage for a few loads? Specifically, with your version powering a 15, 30 & 50watt light bulb in a lamp. Please be careful as (at least in the States), the normally unpowered and exposed 'neutral' of a lamp socket is energized when powered by balanced power. The specifics of the bulbs, ie the specific voltage (220,230,240VAC) and wattage will allow me to  calculate the actual power, adjusting for the measured output voltage. Also, it would be helpful if you would do the same for your CDP, DVD, and other source components. I'd think your DVD player is a rather low draw component, and the hum might require preloading, or we might find that reconfigured caps might help.....
This will allow us to get a better handle on the 'regulation' (voltage sag) under load, and might allow us to configure a more useable Felicia for your environment and needs. Specifically, Farnell carries a 230VAC single primary/ dual 20vac secondary, 100va transformer for <12Lbs that when feeding the Clairtronic from JPR might boost the output voltage by around 5%.

Given the high costs and lack of surplus transformers in Europe, I'd really like to explore the use of the JPR, and possibly the Farnell sourced transformers for European use. This is the reason behind my PITA 'homework' assignment.

Congratulations, and thanks in advance,
Paul

[Builder Brad]

Paul,

I have just tried using the Felica to run my Arcam CD player and the power supply for the Orion active x over at the same time and was blown away with the improvement, I mean the system sounded great already, but the bass notes felt as well defined as every treble note, even at low levels which is something that the Orions are not normally that good with. I tried the Felicia out on the Pioneer DVD player and noticed a change but this seemed to make the music more clinical – I have not decided if I am going to use this player for music anyway as it has always been a little lightweight in the bass department. I will probably try out the Phillips CD-PRO2M once I finish the AKSAs and Felicias.

Here are the results from 1 Felicia with a 3.3uf Polypropylene 630v cap b+b using the 100VA Clairtronic JPR transformers  


GK 1R                           V IN 227        V OUT 209
Arcam @8SE                  V IN 227        V OUT 211
Pioneer media box         V IN 226         V OUT 207
Pioneer DVD 868avi       V IN 228         V OUT 217
Sky+ satellite box          V IN 227         V OUT 214
Orion power supply        V IN 229         V OUT218  
60 Watt light bulb           V IN 231         V OUT 200
43 Watt light bulb           V IN 227         V OUT 204

I hope this helps, FYI there was some fluctuation of the mains voltage while I carried out this test, the figures given are an average taken over a number of readings.

Brad

[GEC]

I spotted a A41 series Signal transformer while browsing the C & H Sales Co. catalog.  It is listed as a Signal A41-80-1487, primary = 120/240, dual 12 vac secondaries @ 3.3 amps each.  $10.00 ea.  5 for $40.00.   Stock #TR2050

http://www.aaaim.com/u/web/aaaimc/cgi-local/shop991/shop.pl/SID=31676744/page=TRFS.htm#TR2050

http://www.aaaim.com/CandH/index.htm

They don't have quite the current rating as the specified transformer, but still might work for CD players, ect.  

Occam, what do you think?

George

[Occam]

Brad,

I'm quite chuffed that your finding Felicia to be a positive addition to your system. I think you'll find that additional 'betwixt and between', output, and bypass capacitance will provide substantial, additional improvements.

So here is what I did with your measurements -

Assuming those lightbulbs are rated for their wattage at 230VAC, I used the following formula to make some calculations.
 P = V^2 / R
So we can calculate the nominal resistance under load of the 60Watt lamp as 882ohms, and that nominal resistance of 1230ohms for the 43watt bulb.

Using the same formula but with the now known resistances [and yes, that resistance will be lower with less that 230vac, but we're simply doing a first order correction], and the actual measured, driving voltages, we have the 60watt bulb consuming 45watts, and the 43watt bulb consuming 34watts. This ties in nicely with a linear extapolation to the GK1-R voltage droop, as I've measured my own Swift with a power meter at about 20watts. A measurement with a 10-30watt bulb would confirm the calculations, but I've imposed enough.

So what conclusions can we draw from the data?  This, and my own measurements Stateside with different transformers leads to the conclusion that the Felicia topology just dang droops too much. This is a result of the inherent 'transformer regulation' and the fact that we're using 2 transformers which exacerbates the voltage sag under load. This manifests itself by certain components [with low voltage monitoring] simply shutting down and not functioning powered by Felicia. None of my own components do this, but this has been reported with Audio Research preamps.

While this doesn't appear to be a problem with your own components, for general use I'd suggest using this transfomer from Farnell as the input transformer,  Order Code: 696821  -
http://uk.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=696821&N=401
Its 25 odd pence more than the Clairtronic from JPR.
This has a single 230V primary winding and dual 20V secondaries. For input you don't need the split primaries. I assume you've wired the secondaries in series for 40v. If you've wired them in parallel, just rewire in series as this will minimize losses. When you use your Clairtronic transformer from JPR for output, its 40v series connected secondaries will produce about 10VAC higher output when exiting their center tapped 120-0-120VAC primary. This should make the EU version of Felicia a bit more flexible. This is assuming that the specification of the transformers are vaguely accurate......

With respect to your Euro-Felicia humming when powering your low draw DVD player, you might find that preloading its Felicia with a 10watt resistor, of appoximately 200-300ohms accross the secondary in parallel with the 'betwixt and between' cap(s) will minimize the hum and improve performance. Certainly, as you've found, running more than one component from a single Felicia will accomplish much the same, but that does not provide isolation between those components which is especially beneficial if those components have a switching supply.

On to capacitors-
The Jantzen-audio.com website that I previous found European distributors through, appears to be MIA. I believe you'll benefit from substantially more [12-20uf, paralleling caps is fine] than your present 3.3uf accross the secondaries. Solens (aka SCR,Axon) work well, though not, IMO, as well as the Jantzens. I've not tried Mundorfs, Audyns, or other audiophile bespoke caps, as I'm a cheap SOB. I'd try the various European produced metallized polypropolene availabe from RS that I mentioned in my previous post. The 40vac on your secondaries give you some flexibility in choice of main and bypass caps. But at your 230vac mains voltage, you must use adequately voltage rated caps, and if they are not specifically X rated, you MUST fuse both output lines prior to the output caps in the event that those caps might fail 'shorted'.
Once you've optimized your cap values, we could consider a group purchase of Jantzen and possibly Auricap capacitors for shipment to some brave soul in Europe for further distribution.

Please keep us updated on your progress.

Regards,
Paul

[Occam]

George,

Good spot! As far as these 80 watt transformers, dunno. Given how we wire them for Stateside use, 40watts would be their maximum, and probably substantially less for optimal use. But they might be pefectly adequate for dvd players, satellite/cable boxes, etc.... But smaller transformers of the same series inherently have greater voltage sag than their larger bretheren, but that might not be a problem for components with switching supplies.
The derating could be substatially less if we give up the balancing feature and wire the primaries in parallel. But I'm still unsure if that balancing facility isn't still a major benefit even for components with 2 pronged plugs.
Sorry for non definitive answer, but I simply don't know. Obviously, you could simply try it. I'd initially use the same values of capacitors, as the differences are more of wire and core size, rather than measured parameters.

FWIW,
Paul

[Builder Brad]

Paul,

Thank you for the input!

I will use the alternative transformers from Farnell to supply the JPL balancing output transformers. Is there any merit in using either 1) a primary transformer with 2 x 24 volt 2ndaries, which would provide about a 1.2 boost to the supply voltage to the JPLs 2 x 20 volt (I know that we would not normally want to place excess loading on circuits designed for 20 volts, but this may be compensated for by the voltage sag) or 2) use a toroid with 2 x 22 or 2 x 21 volt secondaries as the primary transformer (cheap SOB needs satisfied at the expense of a little less hf attenuation, until the AC reaches capacitors.

I have had a quick look around for Poly caps of around 10uf and up and have found the 10uf caps from Rs part no 365-7520 at a healthy 8 quid + VAT a pop, healthy for them, not me!,or Maplins do a similar Polypropylene 10uf cap at £8 inc VAT. I am thinking that if I am going to use the Farnell transformers I will probably find it easier to order the caps from them at the same time, they even appear to stock poly caps up to 47uf – with a free baked bean tin included. The only thing about the Farnell poly caps is that they do seem a bit industrial, but the 20uf is less that a tener, and not that big to cause a concern, given the cost saving.

Any ideas or thoughts on this.

Brad

[Christopher Witmer]

Two thoughts:

1) Within the same family of transformers, the smaller they get, the worse the regulation is going to be. So voltage droop with the smaller A41 transformers would be worse than with the larger A41 transformers. The solution is, as Paul pointed out, to "mismatch" voltages between the two transformers used in the pair in order to compensate. Or, if you have a cheap step-up/step-down transformer (I suppose even an autoformer would work) you might use that to compensate as well. Here in Japan, where 100V is standard, there are many transformes that give a 10%-15% boost so USA equipment can be used with the local electricity.

2) The cost of shipping from the USA to overseas is often cheap enough that folks in Europe might be better off getting Jantzen caps from Parts Express than buying more expensive caps locally.

[RonR]

Hi Brad and Paul,

I've been making some changes recently on my 240V - 50V parallel secondary Felicia:

1. Adding 0.47, 0.1 and 0.01uF Auricaps as bypass groups on the 'Betwixt and Between' cap and across the output. A definite improvement in both cases! - Brad, I recommend you try this.

2. Trying 12, 15 and 18uF 630V Solen Fastcaps in the 'Betwixt and Between' position, the 12uF sounding best, followed by the 15uF, then the 18uF. Paul, is there any case for going lower than 12uF - 9-10 perhaps?

All testing was conducted powering a CD-PRO2M CDP (with Tent clock) and an Aksa GK-1R. Powering the two individually, Felicia's charms seem to improve the CD Player much more than they do the GK-1. Could this be due to the CDP's use of Torroids, as opposed to the GK-1's use of well-designed conventional trafos?

Cheers,

Ron.

[Occam]

Brad,
[edit - I mispoke. I've actually looked up the RS cap you mentioned, and its not a motor run cap as I assumed, but rather an Amp-Ohm FP-CA audio specific cap, that by a second hand report is quite good -
http://home.hetnet.nl/~brian.gee/Cap.html
I'm not familiar with these. They may well turn out to be excellent for this application]
I believe the larger polypropolene from RS that you're referring to are motor run caps. Larry, Phil and others have done extensive experiments with various motor run caps (including the Arcotronics and Ducatti available to you) and have found that lower priced Solen/Scr  low end audiophile caps consistently provide higher subjective performance in this particular application. SCR caps are available in GB from Wimslow -
https://secure.wilmslow-audio.co.uk/acatalog/Wilmslow_Audio_Capacitors_45.html
Other metallized polypropolene caps for audio use are the Audyns -
http://www.audiocom-uk.com/store/prodtype.asp?PT_ID=134&strPageHistory=cat
and Mundorfs, which I don't know a GB source for.
Also possible are the Amp-Ohms available through RS and the Ansar caps from Cricklewood -
http://www.cricklewoodelectronics.com/Cricklewood/customer/home.php?cat=155

Other than the SCR/Solen caps, I've no personal experience with these caps. My personal preference are the Jantzen caps. The website appears non-functioning-
http://www.jantzen-audio.com/
 and I can't access their distributor list. The only EU source I've found is -
http://www.jssystem.it/IT/Prodotti/JS/Accessori/Accessori.htm
and their prices seem to be in line, unfortuneately, with my subjective opinion. Perhaps if you settle on values with locally sourced caps, I can send a care package of Jantzens sourced at far lower prices from PartsExpress -
http://www.partsexpress.com/webpage.cfm?&DID=7&WebPage_ID=197#capacitors
I'm using Jantzen .47 and .1uf caps for bypassing for the 'B&B' position and the mains output position, but their use for your specific mains voltage, would be questionable. Both the SCR and Audyn caps specify their 630vdc caps at 400vac and their 400vdc caps at 250vac, but Jantzen, to my knowledge, does not provide an AC rating for their 400vdc caps.

As to using toroids for the input transformer role, I don't think the sacrafice in hf coupling attenuation is worth it, nor do I know of lower cost toriods availablity in GB. But I've not tried it, so I certainly can't speak to it definitively. When considering secondary voltage 'adjustments', as Christopher mentioned, you must also consider the primary winding's specified voltage. The maths aren't complicated, just a pain..... The suggested Farnell transformer would provide the voltage boost via its lower primary voltage, 230VAC. Using 24vac secondaries to feed the 20VAC secondaries of the JPR Clairtronic output transformer would provide a roughly 20% output voltage increase, and while it might well address the voltage sag issue, you might now run afoul of overvoltage conditions. As the present JPR to JPR transformers are working for your components, I wouldn't press your luck with 24v secondaries, as the Farnell's would seem to address the issue without incurring the wrath of overvoltages.

As to your specific ideal 'B&B' cap values, dunno, you're beaking new ground and you'll have to experiment.

[Occam]

Ron,

Certainly, as the lowest value of the SCR/Solens seems to be the best, trying lower values should be investigated. Rather than purchasing additional caps, you can just wire the 12 and 18uf caps in series (maintianing the orientation of the writing on the caps) which would yeild approximately 8uf. Caps in parallel are additive while  n caps in series are -
Ct  =  1 / [ 1/C1 + 1/C2 +... 1/Cn ] and for two caps this simplifies to
Ct  =  (C1 x C2) / (C1 + C2)
and if you've an ample supply of caps you can use a combination of series and parallel caps to experiment with a range of net values, assuming the caps are of roughly equialent 'qualities'.

Also, as the caps you're using seem to have high voltage ratings, you might consider wiring the secondaries in series, rather than parallel, giving 100vac as the intermediate voltage. This will minimize losses, but might lead to very different optimal capacitance. I think???, this might call for lower capacitances, which would allow for less (lower cost) capacitance, while providing equivalent filtering efficacy.

Your experience with Hugh's GK-1 seem to be the same as my own. As I noted in this thread -
http://www.audiocircle.com/index.php?topic=19198&start=20
I noted that while the GK-1 benefited substantially from Felicia, those improvements were not as significant when compared to those when Felicia powered another very well thought of preamp, the Modwright  9.0 SE. I believe this is, as you surmised, due to Hugh's choice of expensive, custom, shielded dual EI core transformers, which inherently pass far less high frequency mains borne crap than the Modwright's toroid.
The benefits of Felicia are twofold -
Balanced power, which minimizes leakage noise and hum.
and
Power conditioning, which minimizes problems of mains noise and harmonics.

Hugh's choice of powertransformers does somewhat minimize the benefits of later, but still provides whatever benefits for the former.

I'll also extend the same offer to you that I've offered Brad. Once you've settled on 'optimal' capacitor values, I can ship you Jantzen caps to try and compare, if you're interested.

Regards,
Paul

[mcgsxr]

I will let tiangius speak to the configuration that I have, but I can say that I am really happy with the improvements driven by the Felicia in my system.

I am using it on the JVC EX-A1 that I have, that IS my system, running b200 Visatons in an open baffle arrangement.  I have a large ported sub that I turn on for bass intensive music, but for regular 2 channel listening, the little system with the Visatons does the trick.

I am finding a dramatic increase in smoothness, and air - a sense of naturalness that is hard to describe - to the point where it almost needs another volume notch to fill the room the same way, but it does so realistically.

Thanks for sharings this stuff guys!

[Occam]

Hey Mark,

I was sort of hoping for a more detailed description of Felicia's effect on your JVC (after I figured out exactly what the JVC EX-A1 was) with a bit more detail than smoother and more lifelike..... But after reading some of my own subjective comments on various components, I realized that my own positive comments are usually 'mo betta'.
I guess its hard to articulate the benefits of better power (whether Felicia, batteries, or other powerconditioners/balancers.....), as one might not be aware of how badly your ps/mains may be mucking up your sound until you actually hear what Felicia, etc... does for your system. IMO, that smoothness and natualness is not at the expense of real detail, but rather at the expense of hardness and artificial additions that I'd mistaken for detail.
I too am a great fan of dipoles. My own speakers, Alons, have provided me (midrange) dipole benefits for the last 15years.
I'm looking forward to Tianguis's (Larry's) discussion when he recovers from the RMAF. He has been the consitent lead in optimizing the component complement of Felicia. As a techno-nerd, I'm quite flummoxed over the tremendous subjective impact the capacitor choices have yeilded.

Very pleased you are pleased,
Paul

[mcgsxr]

Paul, I can understand that it would be great if I could expand a little on what I am hearing.

Here is an anecdote that I posted down in Vinnie's circle, on the long thread about the OB Visatons.  Basically a non-audiophile came over to my house, and heard the system, quick A/B with the power conditioner - "I cannot believe how clear and lifelike that is" is the statement that came out over and over again.

It is important to mine that statement a little - the clarity he speaks of, is an inherent part of the Visaton sound, but in this case, it was in response to hearing the system without the conditioner, and then after - so that lifelike increase in sound, coupled with a smooth, natural level of detail, is what seems to happen when I plug the Felicia into the signal path.

The little JVC "executive" unit, uses the same amp technology as their F-10 and ES-1 receivers - some form of analog and digital amplification.

Tough to really put it all into words - it just seems way more real, and preserves the strengths of the system.  Also evident is a reduction in listener fatigue - I sat in the basement for 3 hours Friday evening, reading and listening - it has been quite some time since I have done that.

So, subjectively, it is a great experience, that I am at a loss to describe, other than to say that it is obvious to all who hear it, it is a betterment of the enjoyment of the system, and THANKS!

I know that Larry will chip in with some comments, he shared some thoughts on that unit, when he tested it at his place.  I recall that he will be suggesting the captive Volex cord is a useful tip for folks building up their own.

It is also interesting to note that this is already on a dedicated 20A circuit, so I would have thougth that the power was already decent...

[randytsuch]

Apex junior has a transformer that might work, link here
http://apexjr.com/miscellaneous.html

It is the signal BL1752 for $8
Primary 230V Secondary 48VCT 7A & 28VCT 3A
or Primary 115V Secondary 24VCT & 14VCT

I searched, and found a couple posts on it at diyaudio, one said it is a EI transformer, and the other said it weighs 9 lbs.

What do you guys think?
Apex is local to me.  Busy this week, but I could run by and pick up a couple next week.  Of course, my project backlog is kind of long now, building a cornet and rebuilding a ST70.

Randy

[Occam]

Randy,

Thanks, but sadly these aren't appropriate, as the output winding (typically, the primary with the output transformer that we use) must be center tapped, or be comprised of dual windings and have a total voltage rating of 115-120v (for N.A. use, elsewhere we need 220-240) or above.

[and I've already talked to Steve about the dual 41v secondary transformers, but they are neither sheilded or split bobbins]

[Christopher Witmer]

I have found local supplies of CDE (Western Electric) and ERO film & foil capacitors in the 400V-600V range that look interesting . . . they would be a good deal cheaper for me to acquire than, say, Auricaps. Anyone have any experience with these?

I also notice that Audio Note (U.K.) has some tin foil caps that seem to be priced somewhat similarly to the Auricaps. By that, I mean their single-unit prices are not that different. Audio Note does not list a discount pricing schedule on their website so I don't know if their prices go down as quantity goes up as is the case with Auricaps.

http://www.audionote.co.uk/kits/an_capacitors_paper_in_oil.htm

Any comments would be appreciated!

Christopher Witmer
Tokyo

[PorkpieHat]

Transformers - Signal Transformer 175va dual bobbin transformer
http://www.bgmicro.com/prodinfo.asp?sid=078189814814814869201136182&prodid=P ...

These guys seem to have been out of stock for some time. Anybody know of any alternative sources?

[Occam]

Christopher - Sorry for the delay. Film and foil caps are generally perferred over metalized caps. My only caution is that they lack the 'self healing' characteristics of metallized film caps. I don't see any real reason not to use them as long as you use the fuses as 'mandated' in the schematics and their AC voltage ratings are appropriate.

[Occam]

Folks,

I've just talked to the folks at Marlin P. Jones, and I believe these transformers may be appropriate -
http://www.mpja.com/directview.asp?product=7846+TR
They're $18 each.

I've not used them, but according to MPJA they do have dual winding primaries which are required. These are PRC sourced so I wouldn't think they have the consistency of the Signal A41 transformers. Therefore, I'd suggest you measure the seconday voltage, unloaded under power and use the one with higher secondary voltage as the input transformer. The secondaries are center tapped, so you'd simply leave its black? centertap wire unconnected but insulated.

FWIW

[cantskienuf]

Hopes its OK to do a short hijack since you guys suckered me in and I read the entire thread.  Great work, by the way.  The posts regarding loaded voltage and droop got me curious about my own setup, so out came the DMM.  I thought that I was running a simple isolation transformer through JR recipe filters.  The Iso Tx is a Stancor GIS-500, input 115v 50/60Hz, output 115v, 500VA, 4.35 amps feeding one JR filter that powers a Bottlehead Foreplay & a Bottlehead Paramour while the Iso Tx also feeds another JR filter that powers the other Bottlehead Paramour and a Tosh 3960.  My mains run 124v at the wall and 130v after the ISO Tx.  But here is the kicker, I got the 130v measurement from hot to neutral, then I measured from hot to ground and to my surprise found 65v.  Of cource I measured from neutral to ground and found the other 65v.  Wasted a lot of time searching for data regarding the GIS-500 Iso Tx but found nothing that would clue me in as to how it is wound.  I wouldn't think that your garden variety isolation transformer would produce balance power unless it was advertised to do so, since there is a possibility of old gear with neutral-to-chassis connections.  I said before that I had read the entire thread, but that doesn't mean that I understand all of this stuff.  Is it possible that this transformer can be user-wired for either 0-120 or 60-60, or is there a problem with the transformer that I should be aware of.  It has been happily powering this complement of equipment for about a year, never humming, buzzing or getting excessively warm.  Any thoughts would be welcomed.

John