Large capacitor shoot out

[SW1X]

SW1X Audio^TM Design Large Capacitor Shoot Out

Here is a Shoot Out with a difference. You will be used to auditioning Hi Fi components, but now comes the opportunity to audition just a single component within a DAC and gain an insight into the painstaking process of voicing audio components. The subject of the shoot out is electrolytic capacitors with over 1000uF capacity.

Due to our continuous dedication to improve the quality of sound we routinely carry out voicing for all the parts we are employing in SW1X Audio Design products. We are researching the market for better sounding materials and components. On this occasion audio enthusiasts and music lovers are welcome to participate in judging the sound. It is a unique opportunity to find out how passive components (in this case capacitors) sound, even though buried and often ignored inside your audio equipment. Unfortunately the number of referees is limited to 5, therefore do not hesitate to apply to secure yourself a place.

The approach is quite straight forward. We are looking to control for just one factor i.e. one cap in one position. All burned in caps (for 96 hours as a minimum) are substituted one by one into a power supply of I/V conversion stage of 2 identical standard SW1X DAC 1s (one DAC 1 could be also Signature version as the reference). We will audition all caps in the form of a blind test i.e. all caps will be covered and marked with a number. We then will play all caps sequentially for duration of a short song. The referees write down their impressions (either freestyle or on a predefined form) and either discuss them immediately or later after the end of the run.

Refreshments will be served

The objective is to find a cap that sounds least compromised in all aspects.

Everything being relative, we are interested in opinions on a larger scale. There are currently over 10 capacitors short listed but we are open to suggestions. Current list includes:

Rubycon Black Gate STD, AN Kaisei, AN Standard, ZLH
Elna Silmic II, Cerafine, Tonerex, Startget, RA3, RE3,
Philips/Vishay BC 037, 046, 048, 047, 135, 136 Series
Panasonic Pureism, FM
Nichicon Muse KZ, FG

Of course, the list is far from complete. So feel free to suggest or bring any other capacitor with you for the contest.

The venue is located in Coggeshall, 25min off Stansted Airport

Date and time: noon time, Saturday, the 5th of November.

There will almost certainly be opportunity to listen to a hierarchy of up to three different complete audio systems within the SW1X household.

Should you be interested, please do not hesitate to get in touch with us

[Light Dependant Resistor]

A schematic might help readers, to show where said mystery capacitor is positioned.

Could I suggest the list also include a capacitance multiplier using a BC547 and a 2.2uf capacitor
arranged appropriately in the internal circuit. Such a small capacitor which could be a 0603 surface
mount then is multiplied by the transistors current gain expressed as hfe.


Cheers / Chris

[SW1X]

Dear Chris,

Thank you for your input. I am afraid but it would not be possible to publish the circuit design as it is proprietary. All I can say that circuit is elegantly simple and that any change is very audible, so no "golden ears" are needed to hear the differences.

The caps in question are going to be the first capacitor after the rectification (that would be in place of the blue cap in the picture below) before the voltage shunt regulation, which is followed by another cap (which will be exogenous to our experiment).
The rest of the circuit is made of very revealing AN Kaisei capacitors. All caps in question are going to be attached via copper clips, with each cap replaceable in a matter of seconds. Every cap has its sonic signature, which are quite memorable even after prolonged periods of time.

Any other (automated or not) switching method such as relays or mechanical toggle switches are interfering with the results too much- something we would like to avoid happening.

All we are looking for is for enthusiastic volunteers to share, broaden or to confirm our observations.

[bumpy]

I have spent a couple of very interesting afternoons at Slawa's house listening to the audio consequences of changing capacitors, and also power supply diodes. In the comparisons I have experienced, my personal criteria has always been "would I spend good money to own that sound?"

I am past retirement age and my high frequency sensitivity is shot to pieces, but even so the results are far from subtle and a change can easily make or break a Hi-Fi component. Each capacitor has its own signature and I have heard capacitors fitted to £10,000+ DACs sounding pretty awful, so it's not a question of increasing cost automatically bringing you better performance. I suspect we have a few 'manufacturers' on here that know all this, but as a purchaser of equipment, and electronics numpty, I found this a bit of a revelation.

[fatmarley]

Interesting thread. With capacitors, I've found that what works in one piece of kit may not work well in another. They all seem to act like filters and synergy between all the component choices is key.

Not sure if you're interested but here's my experience playing with caps in my old Onix OA21 integrated amplifier (sorry if it's going off topic).
I keep a diary of my experiences because my memory is bad.

4-pole caps in power supply with 47uF Ansar polyproylene on feedback and Mundorf MCap Supreme
on coupling makes a perfect midrange and treble but slow bass. Without 4-pole caps the
sound is far too bright.

Permanently remove 4-pole caps and fit K52 Wet tants in coupling and feedback. Bass punches much harder. Rolling Stones - Beast
of Burden vocals sound harsh. Same track sounds fine with Cambridge Audio AM1 (electrolytic coupling
and feedback)

Samwa 100uf 100v SG (as used by Rega) electrolytic in feedback with CA AM1 electrolytic coupling cap. Not bright or glassy at all
but lacking a bit of detail.

Wet tant in feedback with 10uf MMK in coupling, very good if a little bit safe, maybe a touch grey.

Put wet tant back in feedback and replace Wet Tant in coupling position for Mundorf Supreme 4.7uF and the
sound is a touch glassy in upper midrange (not harsh though). London Grammar is a good test for glassy vocals.
Replaced Mundorf coupling cap with Jantzen Z superior (Wet tant in feedback) A bit smoother and less glassy (best so far).

Solid Tant Feedback (Nos Kemet 100uF 20v T110), Jantzen Z Superior coupling - Good but a bit flat. Replace Jantzen
with Mundorf Supreme, much more open sounding and glassy sound gone. Not sure I can improve on this but may try
a brand new solid tant (Kemet 100uF 6.3v SMD tants on their way).

Thoughts - Wondering if DCL (dc leakage) can degrade the sound? Naim use a very low voltage tant (6.3v) in feedback position.
The lower the voltage the lower the DCL. I've read that DCL goes up in as tants age (I think that's the only thing that changes in a tant)
and Naim users report a sound quality improvement after having the tants replaced (could be because of the main smoothing caps though)

[SW1X]

Dear Matt,

Your observations are true and certainly are have their validity. We are only interested in effects of one factor ( i.e one capacitor) that directly affects the sonic signature of the DAC 1. This is not the first time and not the last time we are voicing our products. Of course there is always an interaction between different components, which is the trickiest part of them all. That is why we by all means avoiding to employ any switches or relays, knowing how those parts interfere with the sound. Every passive and active component of our designs underwent a similar procedure. So, we pretty much know how each part, including PCB, IEC and phono sockets sound like. It would be foolish to claim some absolute accuracy of the findings in experiments which are based on individual and subjective perceptions. Sure, different environmental conditions (different circuits, different people and all other variables that we are not going to control for) will certainly bring variations into the results. However, everything is being relative, every cap has its own sonic signature (a common factor) that will affect any circuit in a very similar way. In an extreme case, a rubbish capacitor will always sound rubbish in any circuit just to a different extent. However, in some circuits one would not even notice that. In our circuits one rubbish capacitor spoils the whole sound irrecoverably.

Unlike with somebody else circuit, the biggest advantage in our experiments is that we can control for every factor, we choose to (one by one of course), in an elegantly simple circuits of our own choice. We repeat experiments similar to this but with different components such as resistors, diodes, conductors, inductors etc. on a regular basis anyway. So, here is an opportunity for curious and inquisitive minds.

Slawa

[fatmarley]

The only slight concern I would have is how a lot of people find it hard to hear differences in unfamiliar systems. I was at a guys house a few years ago and he swapped a preamp over to show me this "large difference in sound" and I can honestly say I couldn't hear any difference, but it was quite obvious by the guys reaction that there was a difference.

Have you heard about the Harbeth challenge? Alan Shaw believes all amplifiers sound the same and he was happy to put his money where his mouth is. He was offering a pair or free M40.1 speakers to anyone who could identify different amplifiers under a blind test. Obviously amplifiers don't sound the same, so I'm guessing that he knows how hard it is to hear differences in unfamiliar systems (or maybe it's his speakers that aren't very revealing )

[SW1X]

The only slight concern I would have is how a lot of people find it hard to hear differences in unfamiliar systems. I was at a guys house a few years ago and he swapped a preamp over to show me this "large difference in sound" and I can honestly say I couldn't hear any difference, but it was quite obvious by the guys reaction that there was a difference.

Have you heard about the Harbeth challenge? Alan Shaw believes all amplifiers sound the same and he was happy to put his money where his mouth is. He was offering a pair or free M40.1 speakers to anyone who could identify different amplifiers under a blind test. Obviously amplifiers don't sound the same, so I'm guessing that he knows how hard it is to hear differences in unfamiliar systems (or maybe it's his speakers that aren't very revealing )

Your concern is well justified. It is a question of how revealing the rest of a system is. Cannot speak for anybodies else system but in our system(s), where everything is made of finest materials, one cap (or any other component) makes a dramatic difference. That works without having very trained ears. After all there is always a reference of how it sounded before and relative to other DACs (performance level 1 vs level 2 vs Signature version as a reference).

You are welcome to come over and to hear it for yourself

[fatmarley]

You are welcome to come over and to hear it for yourself

It's a bit too far for me, otherwise I would.

Hope all goes well. I'll be interested to hear the what people think.

[bumpy]

On my own system I have never found comparisons after after making changes particularly easy unless they are massive. I think it's all that jumping up to change cables etc, and the additional 'pressure' of judging your own system. At Slawa's however every change seemed much more obvious. I think the reasons for this are several.

1. Slawa does all the jumping about.
2. Tracks are selected that reveal all the required elements of high frequencies, low frequencies, sound stage, clarity, naturalness etc within a short period - maybe a minute or two.
3. Gaps between listening passages are short, which for me with the attention span of a gnat is great.
4. Repeated use of a quality reference component such as a Blackgate capacitor helps to anchor the comparisons.
5. Slawa has a very revealing system, so there is no hiding differences.