Saturday, November 20, 2010

Telos Audio Design RCA Caps

Telos Audio Design (http://www.telos-audio.com.tw/) was almost unknown in Singapore until recent distribution by local distributor, Audio Basic. Telos has beautiful and well made RCA caps. The interesting thing is the manufacturer's claim of sonic benefits from using these RCA caps to cover unused inputs and outputs. Bear in mind that their caps are of non-shorting design, i.e. there is no shunt of positive to ground.

Telos caps are made of copper and then plated in either gold or platinum. Fit and finish is excellent and is as good as jewelry grade. Insulation is teflon.


Photos from official website


I have had a set of both the gold and platinum caps for some time now but did not quite get around to writing a post on them. Part of the reason is my difficulty in rationalizing why these caps work so well. The manufacturer claims that they protect equipment from stray EMI and RFI. I think the reason is far more complex than suggested.

Both caps have a not so subtle effect. Putting on just a single pair of caps on an unused input lifted the haze that made the system sound homogeneous and blurred. Vocals in particular focussed tightly and instruments became more distinct and in sharper contrast to the background.

The platinum caps were the most dramatic of the two. Vocals actually became slightly more distant but with increased focus and texture. Micro-detail was excellent and the extension of high frequencies, especially hi-hats was particularly impressive. I noticed that the platinum caps tended to accentuate the sense of acoustic space in the recording.

The gold caps in comparison presented vocals in a more forward manner, but with a touch of warmth and smoothness. High frequencies also were more extended but to a lesser degree compared to the platinum caps. Bass notes gained both substance and extension, something which the platinum caps did not really do. Micro-detail was not as good as the platinum caps though.

How many to use ? And should you combine the platinum and gold together ? This is one situation in which you really need to experiment. Here are some observations I notice during my experimentation with these caps,

- The input being covered matters. If you have say three unused inputs, using just a pair of caps on each of those inputs will yield different results.

- Don't just try inputs but also outputs. You can even try covering the coaxial output of your CD player / DAC.

- You can combine them to get the strengths of both caps. But I preferred using the same type of cap throughout as I felt that the system sounded more coherent that way.

- More is not better. My best results were obtained using just a single pair in any one component. In fact using too many causes the sound to collapse and sound shut-in, sounding even worse than stock !

- Although the platinum caps are potent, they can make vocals too sharp and sibilant, especially if you use more than one pair per component.

At their low cost, Telos caps are a must have. I bought a box of the platinum and gold caps, and probably have enough caps to tune 3 or 4  systems.

Saturday, October 30, 2010

Almarro A-318B SET Tube Amplifier - Photo Essay and Mini Review

Photo Essay

Beautiful and classic workmanship. 18 watts of single ended power. Tube complement - 6SL7, 6SN7, 6C33C.
8 Ohm and 4 Ohm speaker taps, 3 inputs and an IEC inlet with user accessible fuse holder.

Russian 6C33C double triode. From Soviet era missile and Mig Foxbat service to consumer audio. How the world has changed !

Volume control.
 Carved logo on the front panel.
Input selector. There are 3 inputs. The first indent is mute.


RCA 6SN7 GTB and Sylvania JAN VT-229 tubes

Power transformer is inside the chassis. The exposed center "transformer" in the first photo is in fact a power supply choke.


Russian K42-Y2 coupling caps. A surprise, quite uncommon in commercial gear.

Mini-Review

The Almarro A-318B is quite an unusual beast. Single-ended triode and assembled by hand in Japan, the A-318B is affordable, beautiful and powerful - typically these words are not seen together in the same sentence.

Being an integrated amplifier, you save quite a bit of useful money. Total up the cost of a preamp, with an additional power cord, a pair of interconnects, footers, etc, and you realise that the savings are not insubstantial.

Despite its compact proportions, this is quite a heavy amplifier, tipping the scales at close to 20 kg. Much of this weight comes from its massive power and output transformers. The next thing that hits you is the sheer amount of heat produced, not just from the very hot running 6C33 power tubes, but from inside the chassis. An hour or two of operation even in an air-conditioned room will guarantee you a nice and toasty top plate and volume knob.

Operation is generally fuss-free and uneventful except for two things. First, the bias tabs (sitting underneath the tube socket base) may be accessed by itchy fingers - owners with children please take note ! The position of the two tabs are dangerously close to the top plate and accidental contact is not only possible but very likely, especially if you have a habit of biasing your amp in your dimly lit man-cave, after a beer ot two. It is far safer to take the bias from the two metal screws directly above the tabs on the ceramic tube scoket base. Secondly, I had intermittent contact with one of my power tubes. This traced back to a slightly loose tube socket. My amp is about 3 years old and was bought pre-owned. Anyway, I re-tightened the sockets with insulated needle nose pliers (you have to turn the amplifier over and take off the bottom plate to do this) and did not have any further incidents.

Right off the bat, it is obvious that the Almarro has more drive than its low power suggests (18 watts SET, but my set was delivering probably close to 15 watts at maximum due to my choice of a slightly lower bias point).

In the lower frequencies, the Almarro is no shrinking violet and has enough grunt and slam when driving my Focal Micro Utopia BE speakers (90db sensitivity, 8 Ohm load). The bass is not the most extended or deep (leave that to my Class D amps) but has sufficient heft and articulation. That being said, the Cary SLI-80 has deeper and more powerful bass.

Coming to the midrange, this is probably where the Almarro defines itself. Vocals have a beautiful glow and are open and realistic. Brass instruments and strings are equally well portrayed, with more emphasis on tone and acoustic space.

High frequencies are similarly open with cymbals shimmering in the right way with correct emphasis on both the transient and the decay.

The Almarro is a beautiful amp designed to appeal to the emotional side of things. From the logic side, the Almarro does not have the best of extension at both frequency extremes. It is easily bettered by the Cary SLI-80 in this respect. Resolution is good but not world class. Soundstaging, imaging and separation are acceptable to slightly above average. Despite all this, the listener is too busy listening to the beauty of the Almarro's tone to notice or care about such things. The feeling of holographically "being there" is a strength of this amp How the Almarro manages this without being a champ in imaging and soundstaging is baffling !

Asking my partner for a second opinion, she concluded that the Almarro was beautiful but somewhat emotionally draining, while the Cary was more balanced. I reckoned that this has more to the do with the high level of emotional engagement of the Almarro.

If you are the sort of listener that wants to be able to feel the emotion of a violin concerto instead of being able to discern the exact placement of all performers of the stage, bowing technique, what they had for lunch, etc, the Almarro is definitely for you. As long as used sensibly with speakers of suitable ease of drive, the Almarro is able to deliver a slice of high-end at real world prices.

Monday, October 18, 2010

Audio-Gd DAC19 DSP

Talk about quick shipping ! My order with Audio-Gd has been pending for quite some time now as I wanted some customised inputs done (gave up the USB input to convert to another coaxial input). It was shipped out on Saturday afternoon and arrived in Singapore at my doorstep on Monday evening.

The order process was hassle free and the unit was well packed and arrived in good shape.

The DAC19 is based on two Burr Brown PCM1704UK DAC chips paired with Audio-Gd's proprietary DSP filter. Audio-Gd's principal, Mr. He Qinghua has made an announcement that he is discontinuing his products based on the PCM1704UK due to difficulties in obtaining supply of the chip. That was enough reason for me to take the plunge.

You can refer to http://www.audio-gd.com/Pro/dac/DAC19/DAC19EN.htm for full technical details.

The DAC-19 in finished in a shoe-box sized case that is rather utilitarian. The case is decently finished and will not win any prizes for either fit or finish. Given its asking price and performance, this is acceptable to me. I can do without paying a lot more for a snazzier case that does nothing for performance. There is a little bit of free play on the front selector switch, but otherwise, the rest of the switches and jacks are functional and do the job.

It has been suggested elsewhere that the DAC-19 is not particularly sensitive to quality of transport, digital cables etc, or power cables, by reason of its powerful jitter reduction and power supply quality respectively. I believe that it is wrong to disregard those factors and use of the DAC-19 over the short time I have had it suggests that strong dividends may be reaped by paying careful attention.

Transport duties were handled by Slimdevices Squeezebox 3, linked with Oyaide's DB-510 digital cable. Out of the box, the DAC-19 sounds detailed and resolving in the midrange and high-frequencies, albeit sounding a bit bleached and light weight. Bass in particular is not deep or impactful and the overall balance is a bit dry. Things changes drastically after extended burn in, with vast differences heard past the 50 hour mark and 200 hour mark. New owners who suffer from buyer's remorse upon hearing the DAC-19 would be well served to persist in their burn-in duties and not give up !

Once well cooked, things become a bit interesting. Both the top and bottom end of the DAC-19 open up and you get tight tuneful bass, as well as extended and airy highs. What you do not get is any form of euphony or colour in its presentation.

Comparing the DAC-19 to my Lite DAC-50 was an academic lesson in extremes. First off, my Lite DAC-50 is quite extensively modded, with changes in the power supply as well as some circuit modifications in its tube output stage and coupling caps. Once modded, the Lite is rich, organic while sounding open and dynamic. It would be considered by most to be a musical sounding DAC. It also has a strong sonic signature and its richness of tone as well as its weighty and deep bass are obvious in all recordings.

The DAC-19 sounds neutral, rich or lean, depending on the recording. It seems truer to the recording than most, and as such will not help systems that are deficient in certain areas. As such, the DAC-19 would work best in systems that are already well-tuned for a neutral  source. Paired with the Acrolink 4020-7N power cord, the DAC-19 sounded a bit bright and thin. Changing the power cord to Acrolink's factory terminated 4030 power cord fixed this..

Similarly, a bit of tuning was needed in respect of the footers supporting the DAC-19. A trio of Finite Element's Ceraballs made the sound too forward. Replacing that with Golden Sound's DH cones struck the best balance between cleaning up the sound and adding some weight to the presentation of the DAC-19.

Describing the DAC-19's sound is more difficult than most equipment, because it does not seem to have any intrinsic sonic signature of its own.However, after extended listening, the one striking quality of the DAC-19 is its ability to resolve and present instruments and voices in the most complex of mixes in a coherent, well placed and separated manner. The Lite DAC has a tendency to spotlight the main vocals and principal accompanying instrument, with the other instruments relatively obscured. The DAC-19 resolves both well, with a surprising amount of low level detail that is not immediately apparent on other equipment.

For it's asking price, resolution of this nature is class leading. I am quite sure that a DAC of this quality with a Western manufacturer badge and snazzier case could easy cost 3 times as much as the Audio-Gd. If you are looking for a DAC that digs deep into your recordings and presents a true picture of what's there, you would be well advised to check out the DAC-19.






Pictures from Audio-Gd's official web-site

Postscript

My Audio-Gd recently started losing sound in one channel (December 2013) after 3 years of ownership. I loaned the unit to a friend and he was getting intermittent drop-outs that were almost impossible to recreate.

When I received the unit back, one channel was totally dead. I popped the hood and reseated the DSP board, and it works perfectly now. My guess is that despite being tightly screwed down, the pin connectors may develop contact issues over time. The movement during transport certainly didn't help. Worth a shot if you having problems with your unit.

Wednesday, September 8, 2010

Capacitor shoot out

UPDATE, November 2019  - Time really flies. It's been 9 years since this article was first published and it is about time to add a few more capacitors to the list. This time, I will also have comments from the very trusty TC who will be volunteering both his equipment and time. A list of the new capacitors that will be tested :-

(i) Audyn MKP Plus
(ii) Clarity Cap CMR
(iii) GAD-viva 
(iv) Miflex KPCU
(v) Modwright MOIP (discontinued) 
(vi) Mundorf Silver / Gold / Oil
(vii) Panasonic box caps
(viii) Panasonic ECWFD film caps 
(xi) Jantzen Audio Silver Z
(x) Rike Audio S-Cap 2
(xi) Russian K42Y-2
(xii) V-Cap TFTF (discontinued) 
(xiii) V-Cap ODAM
(xiv) Vishay MKP1839HQ

Special Appearance

(i) Audio Note (UK) Kaisei bi-polar capacitor 
(ii) Jensen Pure Copper Foil Paper-in-oil type (Aluminium can)

Do check in from time to time as we will post updates periodically.

Part II


Regrettably, Part II of this capacitor shoot-out took a lot longer than planned. The test platform had to be abandoned due to a failed power transformer, with no repair timeline in sight. A new candidate was interviewed and gallantly volunteered for the arduous mission ahead.




Our very brave soldier is a tube preamp with only a single coupling capacitor in the signal path. I measured a peak of about 150 VDC before the capacitor. The stock capacitor installed was a 1uF / 250 VDC plastic film capacitor. The partnering power amplifier has an input impedance of 200 KOhms which means that a minimum capacitor size of 0.47 uF would be required to avoid bass roll-off.

I installed screw terminals to allow easy installation and removal of the capacitor on test. All capacitors used in this test received a minimum of 100 hours of burn-in on my Audiodharma Cable Cooker, with the exception of Teflon film capacitors that received double the burn-in time.

When the capacitor is marked to indicate the outer foil, that is oriented towards the source. Otherwise, I oriented the capacitors in the direction of the writing on the label. Two commonly methods of determining the outer foil of a capacitor are described online - one using an oscilloscope, and the other using a guitar amp. I tried the latter, but found that it only worked for certain small value capacitors.

Audyn MKP Plus


The Audyn MKP Plus utilises a series connected bi-filar wound polypropylene film. The inductance-free design is also claimed to be ultra low-loss and designed for extreme impulse / power handling.

This capacitor put up a really good showing despite its very affordable price tag. It is quite linear and neutral sounding, except for the midrange which is slightly warm and laidback. The staging is a bit more forward than the rest of the capacitors here, but otherwise there is plenty of width although depth could be better. Imaging is tight, with good resolution. 

Like the Gad-Viva, this is a really compact capacitor. Considering that this is a bi-filar design, this is really impressive ! 

This is my top pick among the budget capacitors.  

Clarity Cap CMR


Clarity Caps have always impressed me with good value for money offerings. The CMR is not cheap though, and they are far larger in size compared to their budget offerings.

The CMR is described as using CopperConnect technology, a new method of connecting the lead to the capacitor electrodes. Traditionally, the lead is connected via a thermal arc spray of tin-zin. CopperConnect introduces an embedded copper lattice instead, to dramatically reduce grain boundary crossings and signal path resistance.

This is a high performance capacitor with a neutral tone and high levels of resolution. It has very good staging and plenty of power in the bass. There is also good tonal density throughout that gives this capacitor a very "firm" sound. Compared to the Jantzen Silver Z, this capacitor has more balls and less high frequency emphasis. 

GAD-viva Audio Cap



GAD-viva capacitors are produced by Selectronic Kondensatoren in Germany. The MKP model on test here is their entry-level capacitor. They also have silver-gold and Teflon film models. I picked this up from my local electronics surplus store for a modest sum.

This capacitor is very compact and with a working voltage of up to 630 VDC, it will be a suitable candidate for installation in tight spaces.

If you can obtain them at a good price, this is an excellent value for money capacitor and a significant upgrade over no-name capacitors. It is dynamic and open sounding, with an engaging sound. There is also good detail throughout the frequency range and precise staging. It has a drier sound compared to the Rike Audio S-Cap 2, and a slight roughness in the midrange and high frequencies is my only criticism against this capacitor.

Jantzen Audio Silver Z





Jantzen Audio describes this capacitor as offering extremely high performance, at a reasonable price point. The design uses a "Super MKP double foil design" where four times as much foil is used compared to a single foil capacitor. I am guessing that this is a series connected double capacitor like some Mundorf models.


The capacitor is Nitrogen filled and the lead wires are made of pure silver - not bad at all for a capacitor that does not cost the earth.

This is a neutral capacitor with very high resolving power. There is a subtle projection of the midrange and high frequencies, which puts the soundstage slightly forward. High frequencies have a crisp and firm tonality, while bass is tight and powerful. The lack of bloom in the midbass may make this capacitor sound too bright in the wrong system.

I would put this capacitor in between the Jantzen Superior Z and the Rike Audio S-Cap 2 in terms of tone. The Superior Z has a more dry and flat sound compared to the Silver Z. Don't let the price tag fool you, this capacitor plays at a totally different level compared to your typical entry level boutique capacitor.

Modwright MOIP


Modwright was well known for their modification work before they launched their own line of electronics. The MOIP is an oil-impregnated metallized polypropylene film capacitor and is the more affordable model in their line-up - their premium offering is a Teflon film and tin foil model.

This has the classic paper-in-oil midrange with a luscious and creamy sound. However, you get a dynamic, tight and punch low-end and an extended top-end. The vocal warmth is slightly behind the Miflex KPCU, which also manages to retain more expressiveness and detail compared to the MOIP. The rest of the frequency range is highly detailed though, and this is a very likeable capacitor. It is also one of the most compact of the boutique capacitors on test here, which makes it a prime candidate when you have challenging installations and your budget cannot accommodate the V-Cap ODAM.     

Miflex KPCU



This is a physically very large capacitor and requires a lot of space for installation as well as very secure fastening (they are really heavy !). Miflex hails from Poland and while their capacitors are not cheap, they have been touted by some as being serious contenders.


The KPCU is a copper foil, paper, polypropylene, and oil-impregnated capacitor. That's a mouthful and you could either end up with a capacitor that has it all, or a jumbled sonic mess. Thankfully, it turned out to be the former.

Not surprisingly, this capacitor has a warmish glow to it, similar to many of the other oil capacitors here. Its glow factor is in-between the K42Y-2 and the Jensen Pure Copper Foil. The organic flow and musicality reminds me of the Jensen - you just want to listen to hours on end. However, this capacitor has plenty of speed when required and an even higher level of resolution. Bass is tight, packs a wallop and has plenty of articulation too. For some reason, plucked instruments come out with more force and projection compared to the other capacitors here. 

Make no mistake, this capacitor is not in the "neutral" camp. However, if you want an organic sound that is also highly detailed and holographic, this is the capacitor for you.

Mundorf Silver / Gold / Oil



These capacitors are on loan from TC, and are larger in value compared to the rest of the capacitors tested, at 4.7 uF. Some people believe that the extra amount of foil may be a handicap as the signal has to travel through more material.

Sonically, these capacitors are towards the warm and rich side. While there is plenty of high-frequency extension, this is firmly anchored with solid bass, and a full and luscious mid-bass. The glow factor on this capacitor is in-between the Rike Audio and the Miflex. Images had a solidity and density akin to increasing the colour saturation on your digital photos. 

Music has a very nice flow although I find that the Miflex is better in terms of sheer musicality.   

Panasonic ECWFD 



According to Panasonic's catalogue, the ECWFD series is made using using metallized polypropylene film with flame retardant epoxy resin coating. The design is also non-inductive. You should be able to obtain this from any large online electronics component supplier. It is also affordable and very compact. The close lead spacing makes this an ideal substitute for a small value electrolytic capacitor


This poor capacitor had to compete with a handicap though - the leads could not reach the terminals on the test-rig, and had to be extended using some wire. Despite the 100 hours plus run-in, the first few hours in the test rig were a bit disappointing, with anaemic bass and a very narrow soundstage.

By the second day, things had improved significantly. Most of the Panasonic's sins were that of omission. This is a very pleasant sounding capacitor with a very natural midrange and decent high-frequency extension. However, this capacitor is noticeably less resolving compared to the boutique capacitors here, although you don't really notice the missing detail until you compare both. Presentation is also quite polite, with restrained dynamics and a laidback presentation. In a pinch, these are perfectly usable and offer very competent performance, although if I was counting my pennies, I would go for the K42-Y2 instead.

Rike Audio S-Cap 2 

Rike Audio of Germany produces relatively affordable capacitors. The S-Cap 2 on test is described as Paper-PP-Aluminium-Oil cap, with non-inductive wiring.

The capacitor leads are tinned copper, and the outer-foil on the capacitor is marked. You will need plenty of space to install this capacitor, it is quite large at 32 mm diameter and 56 mm length.



I liked the S-Cap 2 very much. It is well-balanced with a punchy and tight bass, and extended high frequencies. The tonal balance is somewhere in between a modern plastic film capacitor and a vintage paper-in-oil model. If you are looking for very obvious warmth and glow, you will not find this here. Instead, there is a very subtle glow to vocals with slight warmth. Resolution is good and staging is natural with no exaggeration to either width or depth.

Russian K42Y-2 Vintage Capacitors



Russian vintage capacitors are actually pretty good for audio purposes. Despite legends of these being military surplus (likely) or pulls from missile launchers or the like, every single capacitor I've received over the last few years appear to be new old stock. You can still try telling your kids or grand-kids tall tales, they probably would be none the wiser.

The K42Y-2 is a paper-in-oil capacitor and is available only in small capacitance values. It has a sturdy case and looks like it will outlive it's owner.

If you disregard the relatively expensive shipping from Russia or the Ukraine (where most of the sellers are based), these capacitors are an absolute bargain.

Tonally, the K42Y-2 would best be described as having an inverted-U shape, with a more prominent midrange. I hesitate to describe these as rolled-off at both ends of the frequency spectrum, but both the bass and treble are not as pushed out, and sound relatively recessed.

These capacitors are not as heavy-handed as some other paper-in-oil models on the market. Vocals have a creamy and velvety smooth texture to them, and you lose some articulation in favour of a pleasing liquidity and some warmth. I did not find this capacitor to be syrupy or slow - it has decent pacing and good amounts of detail. 

That famous phrase comes to mind - good, cheap and fast, you can only choose two. In this case, shipping takes a long time. Otherwise, this is an excellent capacitor for the money.

V-Cap TFTF




I've had this capacitor for a while, but never got around to installing it. This is the older version which is physically smaller than the revised version that has now been discontinued. Introduced in 2004, the V-Cap TFTF was VH Audio's premium capacitor until the CuTF series was launched. The TFTF uses teflon and tin foil film. V-Caps are considered some of the finest products on the market, and unfortunately they carry a commensurate price tag.

This capacitor requires lengthy burn-in to get best results. Even after 200 hours of burn-in, they still sounded a touch light-weight and overly smooth. 2 days of use in the actual circuit helped tremendously. 


Some of the best capacitors on test here are like a photographer looking at the world through top-notch optics. The TFTF is akin to putting your camera down and observing the world through the naked eye. It has neutrality and resolution that is unparalleled, coupled with a naturalness that is free from harshness and grain of any sort. This leaves the components to do the talking, and this is truly a capacitor that does not give away any clue that it is there, whether through a distinct sonic footprint, or sonic aberrations of any sort. This is a double-edged sword. If you are a chef with the finest and freshest ingredients, you would do just fine. But if you have lesser ingredients, seasoning goes a long way.

You get tight and powerful bass true to the recording, no more or less. The same goes for the rest of the frequency range. The naturalness of transients means that you may want to look elsewhere if you like a very precise leading edge or other demonstrations of sonic fireworks.

V-Cap ODAM



This is a new product from VH Audio. ODAM stands for "Oil Damped Advanced Metalized". This capacitor uses metallized film that is oil impregnated and hermetically sealed. This capacitor is said to be leak friendly and suitable for vacuum tube circuit use, with a maximum heat rating of 105 degrees C. Unlike the the TFTF I have, the ODAM is compact and should fit nicely in most installations.

These capacitors sound similar to the TFTF in that they do the audiophile equivalent of the Cheshire Cat - they disappear, leaving a wide silly grin (instead) on your face. They have a shade less transparency compared to the TFTF, and a slightly warmer and juicier sound that is more forgiving. I found it easier to be emotionally engaged with this capacitor, especially with less than stellar recordings. Apart from that, you get the extreme resolution, separation and staging of the TFTF.

Despite their lower price tag compared to the V-Cap Teflon film models, I think this would be the better choice for most audiophiles. This capacitor is guaranteed to give you many "Oh Damn !" moments as you savour all the sonic goodies that this has to offer.

Vishay MKP 1839HQ


TC calls this the hulk capacitor, thanks to its dark green jacket. This capacitor will not fly into an uncontrollable rage and smash things, although it does have a certain muscularity to it. Vishay lists this as an AC and pulse metallized polypropylene film capacitor in an epoxy sealed and flame retardant casing. The normal series MKP 1839 is available in a wide range of values up to 22 uF and DC voltage rating of 630 VDC, while the HQ series is available in values from 0.1 uF to 3.3 uF and DC voltage rating of 630 VDC to 1600 VDC !

Sonically, this capacitor is quite neutral with good amounts of detail. Spatially, it does not render space in the way that the boutique capacitors can. While lateral width and depth are fine, the acoustic space around instruments are not apparent - this results in a very precise but somewhat flat soundstage. There is a certain edge and punch to this capacitor that gives it an exciting and muscular sound (this is the Dr. Bruce Banner moment you were waiting for !). Rock music will have that extra punch and violin, that searing edge. It can sound a little bit tiring, so this is not the capacitor for you to relax to at the end of a stressful day. These capacitors are cheap and cheerful, and they are highly recommended if you are on a very tight budget.    
  
Special Appearance

Audio Note (UK) Kaisei Bi-Polar Capacitor




Audiophiles eschew electrolytic capacitors in the signal path. Sometimes, this may be the only feasible option if you require a large amount of capacitance but have limited space.

My prior experience with bi-polar electrolytic capacitors were confined to the Nichicon Muse and the Rubycon Blackgate NX Hi-Q (long discontinued). The Kaisei was an impulse buy - I was surprised to see that they had high voltage versions that could be used in the test rig. A wide range of capacitance values are available with voltage ratings up to 500 VDC.

These capacitors are produced by Rubycon and Audio Note claims that the Kaisei is identical to the famous Black Gate capacitors save that the paper is not graphite impregnated. Hoarders of Black Gate capacitors worldwide should be relieved that the value of their precious hoard is safe - for now.

These capacitors actually sound more than decent, and I would daringly suggest that they are able to outperform generic film capacitors. Neutral they aren't, and the Kaisei would be best described as musical, with a fair dose of showmanship. There is a wet tone, with deep, powerful and chunky bass. Couple this with shimmering highs that seem to have endless decay, and you have a highly entertaining and enjoyable performer. The midrange has a warm and velvety quality that makes vocals pleasing and inviting. While the low and high frequencies are highly detailed, the midrange gives up some expressiveness and inner detail in exchange for smoothness. Relatively speaking, this capacitor lacks the ability to see in to the recording compared to the better performing film capacitors here. Don't get me wrong - you don't feel that this capacitor is a compromise when listening to it and it is highly enjoyable. However, it is not the last word in resolution, precision or neutrality.

If your needs leave you no choice but to use an electrolytic capacitor, you can safely choose this without the guilt or anxiety that you have made an unnecessary compromise.

Jensen Pure Copper Foil Paper-in-oil type (Aluminium can)




I found this in my parts box, a left-over from some project quite some years ago. The value happened to be 0.22 uF, which would roll-off at 36 Hz in the test-rig. That's about the -6 db point of my speaker, and I didn't detect any loss of bass.

Listening to this capacitor is like enjoying good Affogato. It's as simple as can be, but if you have  a high quality espresso shot and vanilla ice-cream, it can be absolutely sublime. With the Jensen, you have inner glow that lights up the soundstage with plenty of shading and detail. There is plenty of air in recordings, and the sense of space in the recording is reproduced with spooky realism. This character is stamped on anything that passes through it, so too bad if you don't like Affogato ! The sweet, rich quality of the Jensen takes the edge off sibilance and harshness. Tempo wise, the Jensen takes it time, and may make faster recordings sound a bit ponderous.

Part I 

Oh No ! Not another capacitor comparison test !

Actually, no one likes comparing capacitors. Do we really have nothing better to do in life but to swap capacitors in and out of circuit, burning in numerous capacitors just to find out how they sound ?

Right now, the stock Wima MKP10 output coupling caps in my Diva Audio M7 have been taken out and the wires soldered to alligator clips instead, to facilitate ease of swapping the caps in and out.

Unlike some testers than undergo thorough and scientific methodology, there was no blind testing, or gruelling 500 hours burn in test. Neither are all caps of identical value because many of these caps just happen to be lying around for trial. But according to my calculations, all of the capacitors tested are large enough in value to not cause any audible degradation to the bass response in my system.

I also happened to need to conduct some tests on the power supply, so some of these caps were used as a bypass cap in the last stage of the C-L-C power supply of my M7. The values used weren't consistent, and the listening notes there are included just for interest and completeness sake. I've included some of my personal experiences of these caps for crossover use too.

Please do not use any of these capacitors in AC mains filters - they are not properly rated for such applications !

The line-up (in no particular order) :-

1. Clarity Cap ESA
2. Solen Fast Cap
3. Auricap
4. Obbligato Gold Premium Cap
5. Jantzen Superior Z Cap
6. Mundorf M-Cap
7. Mundorf Supreme
8. Mundorf Supreme Silver in Oil
9. Mundorf Supreme Silver / Gold
10. Ampohm Paper-in-oil Tin Foil



(Top Row, Left - Right, Solen, Obbligato, Clarity Cap, Auricap, Mundorf M-Cap)
(Bottom Row - Left - Right, Jantzen, Wima, Mundorf Supreme, Mundorf Silver / Gold, Mundorf Silver in Oil)

For a value reference, here are the online prices of the above caps for 1.0 uF in USD arranged in order from the cheapest to the most expensive.

Solen                                               $1.76
Mundorf M-Cap                              $3.54
Wima MKP10                                 $4.00
Clarify Cap ESA                              $8.90
Obbligato Gold Premium                $10.50
Jantzen Superior Z Cap                  $12.00
Mundorf Supreme                          $20.00
Auricap                                          $21.50
Ampohm Paper-in-oil Tin Foil        $29.95
Mundorf Supreme Silver / Oil         $48.00
Mundorf Supreme Silver / Gold      $68.00

Stock Cap - Wima MKP10

Absolutely nothing wrong with the Wima. The MKP10 is a common sight in quite a lot of expensive equipment and instantly recognisable by its red rectangular box appearance. I know that T.S. Lim of Diva Audio favours this cap for its neutrality and dynamics.

It is a neutral cap and in the wrong systems can sound a bit lean. It is quite open and gives the impression of an overall lack of euphony or bloom. Although it has a relatively smooth midrange, when things get busy, the midrange can take on a bit of glare and hardness. In such situations, the treble becomes a bit tizzy and messy. This was made very obvious when going back to the Wima from the Mundorf Silver / Gold.

In terms of soundstage depth and presentation, the Wima is like sitting close to front row. Mundorf capacitors in comparison are more like sitting in the middle row.

Clarity Cap ESA


A very pretty cap and its metal foil body looks impressive. Initial impressions are that of a very dark capacitor with recessed midrange and not much treble extension. Thankfully, after a few hours of burn in, things improve  quite  lot.

This is an interesting capacitor. It has a weighty mid-bass that gives lower piano notes good solidity and feel. Vocals sound inviting and smooth, with almost no trace of sibilance on the usual problem tracks. Further listening reveals that the midrange is recessed and slightly less resolving as the Wima MKP10. Unlike the Wima MKP10 that has a dry and honest treble, the ESA has an airy treble and high frequency sparkle that highlights the decay of cymbals and high hats, and "enhances" the sense of acoustic space in recordings.

This could be an ideal cap to tame overly bright and lighweight sounding systems without making the overall presentation too dark. Given its relatively modest price by high end cap prices, this cap has plenty going for it.

Auricap

Auricaps come is a nice bright yellow wrapper and have insulated multi-stranded leads, one of which is black and the other red, presumably to differentiate the outer foil of the windings from the inner foil.

Audience, the manufacturer of Auricap, recommends that the signal enter through the black lead and exit through the red lead for signal coupling purposes, which is the way I installed them.

Moving from the Clarity Cap ESA to the Auricap restored my system back to the same tonal balance as the stock caps - neutral. Don't make hasty conclusions about this cap. For the first two hours, although it sounded neutral, high frequencies had a strange wobbly quality, a bit like tape speed variation. After about five hours, this more or less disappeared.

Compared to the Wima, the Auricap has a smoother midrange but a neutral balance through the whole audio frequency spectrum. The ESA has more air and high frequency sparkle than the Auricap. You can say that the Auricap does nothing wrong, but look elsewhere if you are looking for a cap to colour the tonal balance of your system.

Used in the power supply, this falls somewhat between the Solen and Mundorf Supreme. Definitely more open sounding that the Solen, but it doesn't quite have the musicality or openness of the Mundorf.

Mundorf Supreme

The Mundorf Supreme is the bottom of the Supreme range and is physically huge for its rated value. This is probably some part due to its induction free design which effectively uses two capacitors in series within the same casing. Do check the space available in your casing before you buy !

The Supreme ended up with a little more burn in than usual due to a strange phenomenon. The first few hours were fantastic ! Smooth, liquid and the most beautiful and lingering decay from notes. Things then took a turn for the worse, with the caps entering into a decisively unhappy state - the midrange in particular was hashy and grainy.

Way past the 10 hours mark, things began to settle down and serious listening could commence.

Coming from the Auricap, the Supreme was on the other side of the fence, highly musical, entertaining and perhaps not the most accurate sounding of capacitors. Although the tonal balance is quite neutral, the Supreme has a very polished and refined midrange with the right amount of meat throughout the frequency range. Musical notes are presented with texture and fine nuances, making the Auricap sound dry in comparison.

Easily the most pleasing of the caps tested this far, the Supreme combines the weight and treble extension of the Claritycap ESA with the speed of the Wima MKP10. Coupled to its highly resolving and musical nature and affordable price, do consider the Supreme for your next purchase. To nitpick, the only criticism against the Supreme against its competitors so far would be a slight loss of resolution in extreme high frequencies, and its artistic rather than honest approach towards music. The latter point is subjective anyway and you may personally have a preference for this.

This cap is also very good in power supplies. Apart from weight, it has speed and bloom.

This is also my favourite capacitor for crossover use.

Mundorf Silver/Gold


The Mundorf Silver/Gold sounds remarkably like the Supreme. What does spending 3 x more get you ? Highs are more extended with a better sense of air and resolution. Midrange has a warmer glow to it. Overall this cap sounds slightly more liquid, a bit like how the Supreme sounds initially (the subject cap here is very well run in since it is on loan from a friend who has put considerable hours on it) However, despite the subjective improvements, the value proposition is hard to argue. If funds are unlimited, this is a moot point. But if you have a choice between choosing the Supreme for 3 critical locations, compared to using the Silver/Gold for just one critical location, I would choose the former without hesitation.

Mundorf M-Cap

Compared to the Wima, the M-Cap sounds softer and more rounded. As a result, dynamics suffer a bit, with bass notes lacking in impact and extension. The Wima sounds a lot more open in comparison although the M-Cap does have a pleasingly smooth midrange. Unfortunately, the M-Cap sounds smooth yet has a sibilance problem in the midrange. In the upper frequencies, this cap sounds dry and restricted. The treble also has a tendency to get splashy when things get busy. The only conclusion I have is that this cap is probably more suited for some other application and is not suited for high voltage coupling use. This is the only cap so far in listening tests that make you want to reach for the power switch !

Mundorf Supreme Silver / Oil

What a breath of fresh air ! Coming from the M-Cap, the Mundorf Supreme Silver in Oil is a treat for the ears. The Mundorf Supreme family of capacitors have a distinct family sound. The Silver in Oil is much more liquid and open compared to the Supreme. I actually prefer this to the Silver / Gold. The Silver in Oil is very extended at both ends with excellent microdetails in the midrange and high frequencies. It is also exquisitely refined with an excellent balance struck between being analytical and musical. It lacks the midrange glow of the Silver / Gold but is more even throughout the entire frequency band. At all times, it sounds effortless and natural. Strongly recommended !

Obbligato Gold Premium Cap

Initial impressions during burn in time were quite promising. A very even handed performer with a neutral balance and good detail throughout. Balance wise, this reminds me of the Auricap the most except that the Obbligato has more extended and wetter highs. Midrange is pleasingly smooth without being muffled and there is plenty of information being conveyed in a tidy and controlled fashion. The Achilles' heel of this cap is its bass which is slightly rounded and not particularly deep, especially compared to the Mundorf Supreme series. This results in a somewhat lighweight sounding presentation. That being said, this is a very good cap, especially considering its competitive price. Subjectively, I feel that except for the bass issue, the Obbligato is more pleasing than the Auricap at a much cheaper price.

Jantzen Superior Z-Cap

The Jantzen Superior Z-Cap struck me as being remarkably similar to the Obbligato except for two material differences. Firstly, the Jantzen has a more extended and prominent bass, and high frequencies are fractionally more open and extended. With outstanding neutrality from top to bottom at a modest price, this is a very good cap with excellent price to performance ratio. From a subjective point of view, I prefer this slightly over the Obbligato. If the Obbligato could be said to be a wee bit off neutral towards the warm side, the Jantzen is a wee bit off neutral towards the cool side. My usual comment on neutrality applies, the Jantzen communicates the signal with an even hand - look elsewhere if you are looking for added “spice”.

Solen Fast Cap

According to common Audiophile wisdom, using a cap like Solen in signal carrying duties earns you a one way ticket to the Audiophile Hall-of-Shame. Well, surprise, surprise. Maybe using Solen caps is not the Audiophile faux-pas it is made out to be. The Solen can best be described as inoffensive but not particularly inspiring. On the plus side, it is smooth and pleasant. You can listen to it and fall asleep. Comparisons to the other caps  show that the Solen loses some low level information, with high frequency air and information being most obviously affected. The overall outcome is not life threatening and Solen would probably do fine for limited budget projects. In the test set-up, it fared better than the Mundorf M-Cap. Sonically, its second from the bottom of all the caps here on test. To put things in perspective, given its almost giveaway cost, you could do a lot worse.

This is quite decent in power supply use, with a big and chunky sound.

Ampohm Paper-in-Oil Tin Foil


Words cannot describe how big this capacitor is. I was filled with pride when my package arrived from the distributor of Ampohm, www.audiocap.co.uk (great buying experience - try them !). I excitedly  showed my partner the oil filled capacitors that looked more like a smoke grenade. Don't even think of using them in tight spaces.




 Ampohm capacitor with a Solen cap of the same value for comparison.
You didn't think I was joking about the size did you ?

The Ampohm sounds quite good. Good enough to fall nearly at the top of the heap. Taking into account its relatively affordable price, this is quite an achievement. Unlike vintage paper-in-oil caps or some other current production brands, the Ampohm manages to sound rich, liquid and extended at the same time. Its tonal balance is similar to the Mundorf Silver / Oil or Mundorf Silver / Gold. If compared side-by-side, the Ampohm sounds "blacker" with very silent quiet passages. Initially, there is an impression that instruments like cymbals and high-hats have less detail and decay. However, after extended evaluation comes the realisation that such instruments are equally detailed and extended but put in less stark contrast compared to the Mundorf Silver / Oil. Value for money wise, the Ampohm definitely beats the Mundorf hands down. Although I still prefer the Silver / Oil, I can imagine that the Ampohm could suit other systems better. Highly recommended !

This capacitor also works quite well in speaker crossovers, especially in the tweeter circuit.

Conclusions

Despite having personal preferences, it is worth stating that most of these capacitors would do perfectly well in all but the most critical applications. My favourites at the end of this test are :-

Cost-no-object - Mundorf Supreme Silver / Oil. Close runner-up, Ampohm Paper-in-oil Tin Foil.
Best of the rest - Jantzen Superior Z-Cap, Mundorf Supreme, Obbligato Premium Gold

For the selection of the best of the rest, it is a bit like baby bear's porridge - the choice of "just right" depends on your system. Jantzen if your system needs a wee bit opening up. Obbligato if your system is just right. Between these 3 caps, the Mundorf is for the heart (emotionally expressive) while the Obbligato and Jantzen are for the mind (neutral and truer to source).

Tuesday, August 24, 2010

Virtue Audio M5001 Monoblock amplifier

Virtue Audio is the new kid on the block in terms of manufacturers offering ICEpower based products.

ICEpower is by now quite established and there are many companies out there offering amplifiers based on their modules such as Bel Canto Design, Wyred4sound etc.

I normally do not write detailed reviews but was suitably motivated by the M5001 which avoids being a “me too” product by virtue (no pun intended) of its tube buffer supplied by Dodd Audio.

The M5001 is based on the ICEpower ASP500 module, which delivers 250 watts per channel into 8 Ohms and double the power into a 4 Ohm load. The ASP500 module includes a built in switching power supply and accordingly runs cool and efficiently.

The stock module input impedance is raised from 8 kohm to 100 kohm due to the tube buffer. This presents a much easier load for preamplifiers to drive, in particular tube based designs.

Appearance wise, the M5001 is quite handsome with a well finished case and lovely real wood veneer top. A variety of finishing options are available to customize the look of your amplifier. Round the back, an IEC power socket accepts detachable power cords, and input is via either an RCA or XLR balanced socket. A subwoofer output is provided.

The speaker binding posts deserve a special mention. The propeller posts make finger tightening a breeze. Both the binding posts and RCA socket are said to be made from gold plated Terrilium copper.

It is not quite the epitome of hi-fi bling-bling, but is certainly well finished enough to be proudly displayed on your equipment rack.


(Pictures from Virtue Audio's official web-site)
Dimensions are not quite shoe box like, with the width of the amplifiers being about 10 inches across. This makes placing each monoblock side by side a bit tricky for most equipment racks as you will find that the support columns will either block the AC inlet on the left of the unit or the input jacks on the right. The supplied feet are metal discs that screw into the chassis. As they project out of the chassis footprint, this makes each monoblock occupy a fair amount of real estate. The feet are easily removed though if you so wish.

Let us re-visit my impressions of ICEpower over the years :- extremely tight and powerful bass, high resolution and detailed midrange and treble, effortless presentation. The downside ? Dry midrange, lack of treble air and 2D like image.

After about 15 hours of burn in, and with the stock JJ 12AX7/ECC83 tube installed, serious listening sessions were conducted.

Preamplifier duties were handled by Diva Audio’s tube based M7. My M7 utilises a tube rectified and choke loaded power supply and has been upgraded to the latest specification by T.S. Lim with additional voltage regulators on the power supply and star ground wiring. The M7 can be best described as a linear and fast sounding pre-amp with both speed, dynamics and good bass authority.

After some trial with the speakers available at hand, the M5001 was matched with my main speakers, a Focal Micro Utopia BE.

The first impression was that of absolute control over both frequency extremes. Bass was tight and controlled.

Midrange is neutral with just the slightest hint of fullness.

High frequencies are extended with absolutely no loss of detail.

Resolution, in particular micro-detail is excellent with individual instruments in a mix being discernible even under the heaviest of mixes. One would be even tempted to flog the oft-used and abused audiophile claim of hearing detail in familliar recordings that went previously unnoticed.

The tube buffer would appear to mitigate much of the criticism I had against ICEpower. Images are fleshed out with proper depth while treble air and the sense of acoustic space are delicately conveyed. I did not see any downside from the installed tube buffer since all the things I liked about the stock module remained – no slowness in transients, or loosening of bass grip.

All that being said, this is by no means a tube-like amp. If you want tube liquidity, get a tube amp – this is not going to float your boat. The tube buffer does not honey coat the sound, it imparts a subtle warmth and organic flow to the dry sound of the stock module. Tonal balance wise, it still remains on the right side of neutral.

Choice of tube used in the buffer as well as pre-amp used could go a long way to tuning the sound the way you want. As far as I am aware, the M5001 can be used with most of the 12A*7 family tubes, enabling fairly cheap and flexible tube rolling, since you can avoid the insane pricing in the 12AX7 family and go for cheaper equivalents in less popular families like the 12AT7 for example.

Hyper-detailed and analytical with the subtle touch of liquidity and warmth – coupled with loads of power to control almost any speaker out there on the market. Take into account its relatively modest price, and I think Virtue Audio has an absolute winner on its hands.