I'm new here, but would like to share the results of an experiment described below that showed to me that a cap constructed out of several, smaller (different value) capacitors put in parallel offered a superior result over the single value cap. With all the smaller caps being of the same brand and type that is!! So my estimate is that 2 x 7,5 uF will have a better result than the single 15 uF. Even better will be something like 1x 8,0 and 1x 4,7 and 1 x 2,2 and...
About one year ago a friend and I, who share the same speaker (the infamous magnetostatic Apogee Scintilla, 1 ohm version), made an extensive comparison between multiple caps in parallel versus a single cap. Capacitors used in this experiment: copper cased Obbligatos and Sonicaps. First we tested the caps in the treble section.
The Scintillas treble section (6 dB slope, >3000 Hz) contains two 10 uF caps. We made an external set up in which we could switch quickly between the two 10 uF caps constructed with:
1) single 10 uF Sonicaps
2) single 10 uF Obbligatos
3) 10 uF caps built up out of Obbligatos: 4 x 2,2 uF, 2 x 0,47 uF and 2 x 0,047 uF
We played some cds with a lot of HF information. Especially a cd with metal bells hit by a metal stick reveiled some interesting differences.
The difference between the single Sonicaps and single Obbligatos turned out to be relatively small with the Obbligato being the better cap. I feel our result was in about the same league as the judging of Tony Gee (8,5 versus 10) (google for captest and humblehomemadehifi). The biggest difference however was between the single cap and the multiple cap. The multiple cap turned out to reveil micro-detail like the singing of the metal after it was hit, much better than the single cap. Also the spatial information was better with the multiple cap, the soundstage expanded in all directions compared to the single cap. The most prominent feature however I experienced was that the music as a whole became more enjoyable/natural sounding. Of course it is very hard to tell, but I would not be surprised that the performance of a multiple Obbligato in Tonys test would have been rewarded somewhere around a 12-13.
In front of the midribbon of the Scintilla (300 3000Hz) is one big capacitor: 240 uF (yep, Im saving my money to have this cap one day replaced by a multiple parallel Duelund CAST Ag PIO...). In the stock Apogee xover this cap already is a multiple cap (24 x 10 uF metalized polypropylene Spragues in parallel). My friend replaced these Spragues a few years ago by Sonicaps (24x 10 uF) and he was very pleased with the result of this. Recently he took out 30 uF of Sonicaps and replaced these by multiple Obbligatos. This experiment turned out to be very dissapointing. Disappointing as especially some strange things happened to the imaging. It shifted. After a few weeks the Sonicaps were put back in place and the problem was solved.
This experiment made me conclude that 1) multiple parallel caps perform significantly better than single caps, and 2) it is essential to use one brand/type of capacitor.
BTW: I think it was on the Duelund website that I once noticed a picture of a xover made by some super-high-end loudspeaker company that built their caps with different value VSF-caps...
Kees |
The difference in score that Tony describes between the Ampohm and Auricap (respectively 12- and 9) makes me expect to hear a significant improvement with the Ampohm...
Of course the differences you hear between the caps are very much related to the quality of the entire system as well. The better that system, the more it will be able to reveal the differences between the different caps. |
But are all parameters equal Frederik?
I've got little technical knowledge on this matter but I would expect the 15 x 1 uF multiple cap to have a (even) lower inductance and resistance than the single 15 uF.
All caps suffer from some kind of resonance. The PIO types, and especially the ones created under high vacuum, I expect to have a relatively low resonance, and maybe their resonance will be somewhere in the audiospectrum where it affects the musical result to a lesser extent, but they will suffer from some kind of resonance as well. Maybe, maybe the multiple cap constructed with smaller value caps will have an even more benign resonance character than one big cap.
I think you're completely right about the necessity of having good soldering joints. Experienced this myself with the Scintilla xover (tortured by relatively high currents because of its < 1 ohm impedance) on several occasions. However with a single cap in a xover I expect that good soldering joints are at least as critical... A poor connection with one of the 1 uF caps and the other 14 uF caps connected properly will probably have a better result than a poor connection with a single 15 uF cap.
Kees |
Hi Cady,
I haven't got experience with coupling caps. Never tried it out as for this application the experiences in general are not positive with multiple parallel caps. And it probably will be even more worse with multiple parallel caps built with different brands/types.
Kees |
Hi Frederik,
One 15 uF cap has two soldering joints and 15 x 1 uF has 30 soldering joints?
This is correct of course but do you expect a change in soundquality because of the difference in number of the soldering joints? With capacitors in series I can see the increase of soldering joints can be an issue, however with capacitors in parallel I expect the larger number of soldering joints is less of a problem.
I've experienced the sonic effect of bad soldering joints in speaker xovers and at this point I fully agree with you. I can't be stated enough to pay good attention to it (especially when you use the more difficult to work with high Ag content solder). Bad joints result in lousy sound with strange effects on soundstaging.
The difference in the number of soldering joints I expect however not to be responsible for the good effects that I experienced with multiple parallel caps (a cap built with different values and all being of the same type/manufacturer).
The picture of a multiple parallel VSF-cap (the manufacturer used large values in combination with smaller values) I once saw on the internet (I think it was the Duelund-site) fascinated me. If the results are similar to those I experienced with the Obbligato's, I expect the transparancy of the Duelund cap will increase even further. I would be interested to know how for instance a 10 uF CAST Cu PIO helds up to 2,2 and 8,0 uF CAST Cu PIO.
As this forum is visited by quite a lot of Duelund afficianados that are willing to invest a lot of money on caps I was hoping that one of them would be in for the test ;-)
Kees |
You're right about the price Michael. Since receiving some rave reviews, including on this site, prices have raised to incredible heights. A pity as the Duelunds no doubt are fine caps but IMO and IME the extra quality compared to that of other fine PIO copperfoil caps (and OTHER measures than caps, inductors and wire that can be taken in an audiosystem!!!) doesn't justify the very big difference in retailprice.
I don't know the Cu V-cap, however I've tested the tinfoil V-caps a few years ago and IMO they didn't held up with the standard Jensen PIO copperfoil cap. The difference was big. The tinfoils are fast and detailed but compared to the PIO copperfoils they sound "thin" / less musical. And this judgement came after at least 500 hours of playing in time.
I collected three early cost-no-object early Siltech hybrid poweramps that I've upgraded by a Dutch engineer called Peter van Willenswaard. He used to work for AudioNote UK and now has his own company Audiomagic. Peter is a BIG name with tubes in the Netherlands/Europe. His DAC for instance is a killer. Peter built up a lot of experience with upgrading AN DACs. So much that he decided to design his own DAC. This DAC, though costing about 1/20th of the most expensive AN DAC, performs in the same league as that AN DAC. No wonder it won the first price at a shoot out of the European Triode Festival some years ago.
I have asked Peter to test the tinfoil teflon V-Caps and the Cast Cu-foil Duelunds as I wanted to replace the old coupling caps in my hybrid poweramps by better ones, and these two companies received rave reviews a couple of years ago. A befriended audiocompany in the Netherlands ordered the Cast Cu-foil Duelunds from Frederik as the company was very interested in Peters opinion on the Duelund caps. The V Caps I ordered in the USA.
Peter put them to test in his own design preamp (position of the caps: coupling caps) and audiosystem. The judgement about the V-caps was quickly made. And even after 500 hours, its sound was still not okay in our experience. This became very painfully clear after replacing the V Caps by Jensen Cu-foils: the immediate improvement of the sound with the Jensens installed was SO big!
The Jensens went out and the Cast Duelunds were connected. A long time of playing in followed. Gradually, very gradually its sound got better and better until it performed a bit better than the standard Jensen PIO Copperfoil caps. After a few hundred hours the Duelunds were taken out and returned to the audiocompany...
They made place for the Jensen PIO Cu-foils in paper tube. The paper tube Jensens sounded already from the start significantly better (more detailed) than the standard Jensen PIO Cu foils... So my choice in the end was the paper tube Jensen.
I must admit that my Cast Duelunds belonged to the first badges produced by Duelund as in my first emails to Duelund, Frederik responded that the high voltage Cast caps didn't exist yet, but that they were working on it. Maybe in the later badges other dimensions/design and materials were used?
I'm very curious to your experiences with the Cufoil V-cap, especially how it performs compaired to its tinfoil sister or brother.
Kees |
Hi Michael and Volleyguy,
I know Jimmy's site and I know he loves his Cast Duelunds. Especially the silverfoil ones. Well for the small capital he invested in these caps he really should love them!!
The Duelunds are his number one caps, I believe he then prefers the paper tube Jensens, a bit similar to Volleyguy I guess. In the end Jimmy preferred the paper tube Jensens over the mylar AudioNotes and the copper tube Jensens.
The system in which the Cast Duelunds, tinfoil V-caps, Jensen Alu tube and Jensen paper tube were tested consists of a heavy modified CEC transport coupled to the Audiomagic DAC (same league as the AN 5.1 Signature) and a very fine all tubed preamp and all tubed poweramps, both created by Peter, driving AN speakers (not sure about the model). Though it can't produce very high SPL's, is limitated in the low domain and is way less revealing than my modified Apogee Scintilla's, it is quite a good system (without any plastic cap in the signal path). More important for me was to have the caps tested by a guy I know that is very experienced, has very good ears and puts most interest in tonality (!) in his designs and modifications.
You're so right Volleyguy, about PIO copperfoil caps sounding good right out of the box. Both Jensens and the Cast Duelunds showed this clearly.
I was surprised that the Duelunds didn't show the big difference (even not after hundreds of hours playing) that other people, like you, experienced. But maybe it had something to do with these Cast caps belonging to the very first 630V caps produced by Duelund. I'm interested to hear Frederiks opinion on this. After a very long time the Cast Duelunds outperformed the Jensen in alu cap, but only by a small margin, whereas the paper tube Jensens outperformed the alu tube Jensens right out of the box.
I've not been able yet to listen to Duelunds (VSF nor Cast) in a passive speaker xover. However, the caps in the passive xover of the Scintilla are relatively high values: 240 uF in front of the midribbon and 10 uF in front of the tweeter ribbon. I bought Obbligato caps for my new (nowadays outboard) xover, but I might try out the Duelunds or Jensens in the end for the tweeter ribbon.
I actually would have liked it A LOT when I would have been able to skip the entire passive speaker xover and have it replaced by a linelevel xover. In theory I would be able to do this as I have three stereo poweramps and the Scintilla is a three way all ribbon magnetostatic speaker. There is very good software available that is able to copy the behaviour of the passive speaker xover exactly. The "problem" in my situation that makes me not do this is a small DC voltage on the outputs of the poweramps that is not easily taken away (without affecting the poweramps performance). So I need the caps in front of the delicate foil-only mid- and tweeter ribbons to prevent the DC voltage damages these ribbons.
The two inductors in the original passive speaker xover however are skipped and have been replaced by a linelevel solution. The bass ribbon (kapton backed alufoil) for instance will be connected to the poweramps output directly.
Have you ever thought about going all linelevel xover?
Cheers,
Kees |
Frederik,
Can you please have a look at my question described a few posts earlier regarding my slightly disappointing experiences a few years ago with the 630 V Cast Cu foil caps (coupling caps in a preamp). The Cast caps had been playing for a couple of hundred hours and in the end only slightly outperformed the standard Jensen Cu foil (alu tube).
While this is quite in contrast to for instance Volleyguys experiences I wondered if this could have been the result of the fact that these Cast caps were actually the first produced by Duelund. I remember this fact very well from our emailconversations in the past. Maybe later generations of the Cast caps used different design/materials??? Very curious if this is really the case.
BTW: the tests were performed by a Dutch top designer. He got the caps on loan from the Dutch company De Audiofabriek while the guys of this company were very curious to hear from that specific designer how the performance of these caps was.
The system of the designer is of a quite high standard (see description above), the parameter the designer puts most interest in is "tonality".
The "weakest link" of the caps used in his system is Jensen and AudioNote PIO copperfoil caps. There's not any poly there.
Where the system revealed subtle differences after a long time between the alu tube Jensen PIO copperfoil and the Cast Duelund with the Cast Duelund being slightly better than the Jensen, the difference between the alu tube Jensen and the paper tube Jensen was more significant and immediate with the paper tube being clearly better than the alu tube.
Cheers,
Kees |
Hi Face,
A few posts earlier I wrote:
"The system in which the Cast Duelunds, tinfoil V-caps, Jensen Alu tube and Jensen paper tube were tested consists of a heavy modified CEC transport coupled to the Audiomagic DAC (same league as the AN 5.1 Signature) and a very fine all tubed preamp and all tubed poweramps, both created by Peter, driving AN speakers (not sure about the model). Though it can't produce very high SPL's, is limitated in the low domain and is way less revealing than my modified Apogee Scintilla's, it is quite a good system (without any plastic cap in the signal path). More important for me was to have the caps tested by a guy I know that is very experienced, has very good ears and puts most interest in tonality (!) in his designs and modifications."
The "tubed" preamp and mono poweramps are designed by Peter van Willenswaard himself. He also designed the Audiomagic DAC. The preamp can't held up with my modified Silvaweld SWC1000 but it is still a very good preamp. The poweramps I find harder to rate. Further the system was connected to a Pure Power powerregenerator. btw: this powerregenerator I can recommend very well, it is much, much better than the PS Audio Premier Plant.
However.... more important IMO than the system and the room in which the test was done, is the fact that this system was able to reveal differences between alu tube and paper tube PIO copperfoil Jensens and the tinfoil VCap very well. And the difference in this system between the Cast Duelund and the alu tube Jensen was relatively small... And with this in mind that tonality is the most important parameter to Peter.
So therefore my question to Frederik: is it possible that the fact that the cast caps that we had on loan, were the first produced, is reponsible for our results or is this not a likely explanation? If not, I still would like to try out the Duelunds in my passive speaker xover one day (that is in front of the tweeter as the cap in front of the mids is 240 uF), but the coupling caps in my poweramp and the DAC will stay Jensen paper tube.
Cheers,
Kees |
Hi Frederik,
The caps were returned after the test to "De Audiofabriek". This company unfortunately no longer exists anymore so I don't know what has become of the two caps involved.
The tests were done in between the fall of 2007 and the spring of 2008. The caps were very likely manufactured by Duelund somewhere close to the summer of 2007. I must have contacted you for the first time somewhere close to the spring of that year. In these days only the 200 V cast copperfoil caps were available. When I contacted you, you told me that you were working on a 630 V version. From that moment it took a few months before the first 630 V cast caps were finished.
The cast caps that were manufactured for me were 2 x 2,0 uF copperfoils. They were put into the typical circular paper casing and measured in my memory something like 10 cm diameter and 5 cm height. They were huge and very heavy.
Kees |
Hi Dgarretson,
A few pages back I wrote about a sort of bypass-experiment in the tweeter section of the magnetostatic Apogee Scintilla with its two, highly revealing 1,5 m tall and 0,5 inch wide, pure aluminium foil tweeters.
http://forum.audiogon.com/cgi-bin/fr.pl?cspkr&1211428524&openflup&1366&4#1366
My experiment differs a bit from the more common "single, small-value bypass cap"-experiment (that most of the time uses different caps for the bypass and main cap), as I experimented with multi-parallel caps of the same type/manufacturer. I experienced that this configuration made a very (!) significant improvement over the single value cap (same type/manufacturer as the ones used in the multi-parallel cap). Further I noticed that multi-parallel caps using different kind of caps lead to bad results.
It is a pity that I haven't read so far on this forum of someone else doing this same experiment, as the improvement is not small and the costs are very low. In my earlier post I mentioned that I would not be surprised (based on my experiences and Tony Gee's captest) when the Obbligato cap performs in about the same level as the best Mundorfs when used in multi-parallel configuration. |
It sounds better, not louder IME.
The multi parallel cap reveals more detail than the single cap, however without becoming a "detailed" cap like for instance some of the very high cost polypropylene's or the TFT V-Cap. Its sound can in particular be characterized as more natural.
This might be the result of the multi-parallel cap having a more benign resonance character, is less noisy. But if so I don't know which factor is responsible for this: other resonance frequency spectrum, smaller amplitude resonance, even lower resistance/inductance and/or something else...
The bad results with different caps used in a multi parallel cap might indicate that the resonance frequency as a result of the 1) tightness of the winding (probably a relative constant value for a line of caps produced by a manufacturer, so more or less equal with small and bigger caps of that line) and/or 2) the type of the foil is big.
I've read about low value caps having another time behaviour than high value caps and something about different memory-effect. This would result in bad sound when small and big values are combined in a multiple parallel cap. Maybe, but I haven't experienced it. No doubt there will be a (slightly) different time behaviour, but maybe the advantages of the multiple cap are big enough to compensate for this. And of course in order to prevent this one can build the multiple parallel cap up with caps of one single value, like you for instance will do with the 8 x 25 uF.
Frederik of Duelund put some attention to the multi parallel cap having more soldering joints than a single cap. I don't believe this has anything to do with it. First it is a parallel cap and not a series cap, further I know how bad soldering joints in a speaker xover sound like and it is far from natural/detailed. As I wrote earlier I once noticed a xover built by a professional manufacturer with multiple parallel VSF Duelunds. No doubt the effects I've noticed with the Obbligato's will be relevant for the Duelunds as well. Though the Duelunds will have a high dampened character by nature, reducing the resonance even further by multiple parallel caps might be rewarding with Duelunds as well.
|
3000 dollar is pretty ambitious indeed!
In front of the Apogee Scintilla's midrange is a 240 uF cap. Apogee already used multi parallel caps in the mid 80's as they constructed this cap out of 24 x 10 uF polypropylene Sprague caps. The Spragues are nothing special, still the Scintilla's midrange (a 1,5 m tall 2 inch wide pure aluminium foil) is considered by many professional reviewers as one of the best they've ever heard. No doubt the good sound quality is not the result of the Sprague caps, but of the Scintilla's design (ultra-light ribbon, a special magnet array which houses both midrange and tweeters etc.). However, I would not be surprised when it turns out that the relatively cheap Spragues in front of the midribbon don't seem to affect the sound in a disappointing way as the cap is a large multi parallel cap. Maybe when Apogee's had used larger value Spragues (when available), the midrange might have lost some of its quality.
I btw will replace the Spragues by 21 x 10 uF Gold Obbligato's (size: 30x75 mm), the remaining 30 uF will be smaller value Gold Obbligato's.
In my situation size doesn't matter as I've decided to build an external xover which has several advantages (in my situation) as well.
The 10 uF Obbligato's retailprice is 25 dollar and when you order something like 50 pieces, diyhifisupply in Hong Kong will offer a discount of 50 percent. In my case all caps costed me around 700 dollar.
Of course I would have loved to have the Spragues replaced by pure copperfoil PIO caps but for the extra price so many other upgrades in my system could be made. My hope however is that one day the Chinese (Obbligato?) will decide to manufacture pure metal foil PIO's as well... |
