Your experiences mirror mine.

Duelund resistors smooth out after only a few hours of use.

Also, a single cap in series with a driver will always image better than multiple caps in parallel.

So when are you upgrading the Auricap to something better? 😀

A friend and I, who share the same speaker (Apogee Scintilla, 1 ohm version), recently did an extensive comparison with multiple caps in parallel versus a single cap. Capacitors used in this experiment: copper cased Obbligato’s and Sonicap

The Scintilla’s treble section (6 dB slope, 3000 Hz) contains two 10 uF caps. We had an external set up in which we could switch quickly between:

1) single 10 uF Sonicaps
2) single 10 uF Obbligato’s
3) 10 uF caps built up out of Obbligato’s: 4 x 2,2 uF, 2 x 0,47 uF and 2 x 0,047 uF

We played some cd’s 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 Sonicap and single Obbligato 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). 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 of the multiple cap was better and the soundstage expanded in all directions compared to the single cap.

In front of the midribbon of the Scintilla (300 – 3000Hz) is a 240 uF cap (yep, I’m saving my money to have this cap one day replaced by Duelund CAST Ag PIO ;-D…). In the stock xover this cap already is a multiple cap (24 x 10 uF Sprague’s in parallel). My friend replaced the Sprague’s by Sonicaps a few years ago and was very pleased with the result. Recently he took out 30 uF of Sonicaps and replaced these by multiple Obbligato’s. This experiment turned out to be very dissapointing. Disappointing as especially some strange things happened to the imaging. After a few weeks the two Sonicaps were put back in place and the problem was solved.

This experiment made me conclude that 1) multiple parallel caps perform better than single caps, and 2) it is essential to use one brand/type of capacitor.

Maybe when the bypass cap (when a different type than the main cap) is relatively small the total benefits of this combination will be positive (that is the better quality of the bypass cap outweights the negative aspects introduced as a result of the differences between the caps), however when the bypass value is a significant part of the total value of the cap, the problems introduced by the different type of caps can start to dominate.

Soon I’ll have the xovers in my Scintilla’s upgraded. All caps (also the one in front of the midribbon) will become multiple copper cased Obbligato’s.

Kees

Good to read that your experiences match ours Francesco.

It is well worth the extra costs I guess. The difference between multiple parallel Obbligato’s and a single Obbligato was significantly bigger than the difference between the single Obbligato and the single Sonicap. Of course it is very difficult to tell, but I would not be surprised that the performance of a multiple Obbligato in Tony’s test would be rewarded somewhere around a 12-13.

The editor of the German magazine Hobby Hifi lately mentioned the multiple parallel cap of one type as well. They said something like: “Thirtythree 0,1 uF Mundorf Supreme will most likely outperform the most expensive 3,3 uF Mundorf type. Strange enough, you never read about such an experiment, we should try it out someday soon.”

Cheers,

Kees

My experiences don’t match yours Jimmy. Like Francesco experiences, on all parameters the single cap was outperformed by the multi- parallel cap.

I’m not surprised by the way as I would expect that when for instance the reproduction of details is bettered, the soundstage/layering would also have to benefit from this.

My theory (no more than that ;-)) is that when you put a lot of caps in parallel the overall distortion of the speaker is reduced. Because of what? Maybe a lower overall resistance of the caps and/or a lower inductance (yes, I’m aware that these values are already incredibly low with single caps, still… and the editor of the German magazine mentioned these as a possible explanation as well) and/or a better vibration handling of the multiple cap.

Regarding the latter, all caps have frequencies where they start to resonate, resulting into distortion. Maybe a multiple parallel cap with different values will result in different resonances, which might end up in a less prominent/audible distortion. Maybe smaller caps start to resonate at higher frequencies, beyond or at less disturbing frequencies of the audible spectrum.
Of course the Duelunds, especially the CAST ones, will handle resonances very succesful as well. I believe that this feature is the most important reason for them sounding so good.

Why it works as it works I don’t know, but my experiences all point into the direction of smaller distortions with the multiple cap. As the total result is one that can be best described as a more natural reproduction. I hear more details, more black background, the soundstage expands, the layering improves, but the most prominent feature I experience is that the music starts to become more enjoyable, it just starts to sound more like the real thing.

In your set up, next to bringing back the multiple cap to a single cap, you introduced the Duelund resistor. My friend and I also experimented with resistors in the Scintilla passive loudspeaker xover. The treble section exists of one 10 uF cap and one RC (1,25 Ohm and 10 uF) in series with the tweeterribbon. To go short: the differences we witnessed between various resistors was bigger than these we experienced in our experiment with the 10 uF’s caps in the treble section. So I can imagine that the Duelund in your situation, where the resistor is even in series with the speaker, made quite a difference (as well). I must add though that many resistors we used were not up to their task as they very likely couldn’t handle the very high currents flowing through the 1 ohm Scintilla xover. The Duelund resistor for instance failed hopelessly, despite we used five of these in parallel. A pity as we had read lots of good reviews on this specific resistor.

Cheers,

Kees

Hi Jimmy,

In the Scintilla treble section there are two 10 uF caps, in front of the Scintilla midribbon is a 240 uF cap located. Apogee used 10 uF polypropylene Spragues only in the stock xover. The Spragues have been replaced some time ago by 10 and 20 uF Sonicaps.

First experiment: treble section
We compared 1) two single 10 uF Sonicaps with 2) two single copper cased 10 uF Obbligato’s and 3) two 10 uF multiple caps constructed out of 4 x 2,2 uF, 2 x 0,47 uF and 2 x 0,047 uF copper cased Obbligato’s. So the multiple cap is your #2: all the same brand.

We had made an external set up of the treble section of the xover which enabled us to switch quickly between the three options. The multiple cap turned out to be the obvious winner. It brought the performance of the single Obbligato to a significantly higher level. Based on Tony’s judgement regarding the Obbligato and Sonicap I would rate the multiple Obbligato somewhere in the 12-13 area.

Like you however I would prefer to use real metalfoils (Cu, Ag) seperated by PIO-dielectrum in the xover, like I do in the DAC and poweramps (the Silvaweld SWC1000 preamp is transformer coupled). However because of the high values in the xover, the costs unfortunately are way out of my budget. The 10 uF in front of the tweeterribbon however might be a possible candidate. I think I will try this out once, until that time I prefer to use the same type of cap in front of the tweeter and midribbon.

I will ask Tony if he ever did an experiment similar to ours and if he did, what his experiences have been. He lives by the way quite close to the city where I live, Amsterdam. He once visited me to listen to my system.

Second experiment: mid section
A few years ago my friend had replaced the 24 x 10 uF Spragues by Sonicaps: 11 x 20 uF and 2 x 10 uF. Short after the first experiment my friend took out 30 uF of Sonicaps and replaced this value by a multiple Obbligato cap (2 x 10 uF and 4 x 2,2 uF and 2 x 0,47 uF and 2 x 0,047 uF). The results with this experiment (similar to your #3) were far from satisfying. Just like you’ve experienced, some odd things happened to… yep (!) the soundstage. It was really annoying. The Obbligato’s were kicked out quickly. The lesson learned was not use different brands in one cap anymore.
By the way: like you I think the good results described about adding a small bypass cap of a different brand are probably no more than an effect. It might sound good to the ear, but it is probably nothing more than a compensation for some kind of flaw of the main cap. I don’t think it is the “real” thing, though I realize that the “real” thing probably never will be the real thing as well, I mean: live music 😉

I think that the sound of the capacitor is mostly determined by 1) the resonance behaviour, 2) the quality of the foil with real metal foils outperforming metalized foils and 3) the dielectrium of the isolation with PIO being the most preferable. Of course 2 and 3 are highly related to 1 as well.

To explain the difference we witnessed between the single and multiple Obbligato cap I think a difference in resonance behaviour is the most likely candidate. I’m aware of the fact that a multiple cap will introduce lots of different resonances, however I expect that the peaks of these resonances will be lower as well, eventually resulting in a overall lower noisefloor. Maybe, in addition to lower resonance-peaks, the resonance frequencies of relatively small value caps are less annoying to the ear than those of relatively high value caps. Maybe this is an explanation for what I experienced: a more natural sound COMBINED with an increase of micro-detail / staging.

Finally the currents running through the 1 ohm Scintilla’s xover are cruel. From this regard I can imagine that a multiple cap can handle this signal more easily than one single cap. I know it is highly speculative, but maybe it is a factor…

The Duelund resistor didn’t work in the treble section of the Scintilla. This resistor by the way forms a RC in combination with one 10 uF cap. We put 5 Duelunds in parallel. In theory this should have worked but it didn’t. Maybe we should have used 10 or 15 in parallel. We never tried and the dealer was willing to take the resistors back. I have however skipped this RC out of the passive speaker xover. Its function will be taken over by a small RC at linelevel just in front of the first stage of the separate poweramp that will drive the treble. So in my case there will be only one 10 uF cap left in the passive speaker xover. It would have been easy to have this cap simulated at linelevel as well (the computermodel used for this, something called like SPICE, works extremely well) but I need to have a cap in front of the tweeter- and midribbon for protection as my poweramps produce a small, however for pure aluminium foil ribbons lethal, DC at the outputs (appr. 10 mV). The caps take good care of this.

Cheers,

Kees

HI JIMMY
ANY COMMENT OF COMPARISON BETWEEN THE NEW AND OLD VERSION OF DUELUND RESISTOR WOULD BE APPRECIATE
ALSO PLEASE INFO ME WHERE TO BUY, AND THE PRICE.
I’M IN LEARNING ABOUT RESISTORS.
U MAY REPLY TO MY EMAIL ADDRESS.
REGARDS / YOT

Hi, I believe a small value capacitor of the same type and brand is much quicker fully charged then a big capacitor. In this sense multiple small capacitors in parallel would have less negative effect associated with a capacitor. However it is important to match the size of the multiple capacitors or charge and release time differences between the caps may spoil the effect.

However, I have one question. Would this trick to use more capacitors work for a low-pass filter as well? Because the low-pass filter is placed in parallel and effectively leaks energy away. This leakage may multiply as parallel capacitors increase.

Arthur

Hi all……..Horning Euphrodites use Jensen 3.3 cu caps coupled with Duelund resistors….I am upgrading to Duelund RS caps….does anyone have any advice on this crossover..?
thanks…Paul.