Friday, October 16, 2009

Yet another afternoon of messing around

Last weekend, I had one of my hi-fi mates over for some listening. He was interested to see how my Thiel CS 1.6 was faring in my system, as well as how it matched with the various amplifiers I had on hand.

For those of you know who are not familiar with the Thiel CS 1.6, it is the smallest floorstanding model in Thiel's range. As a matter of line up, it is actually the replacement of the CS 1.5. Ultra compact models like the 0.5 do not have a direct successor model.

A typical Thiel design, it is designed to be phase coherent as well as time aligned (provided you sit at least 8 feet from the speaker). It is a two way speaker, sporting all metal drive units. Unlike older Thiel models, the CS 1.6 uses in-house produced drivers. Instead of using a conventional rouind port, the CS 1.6 utilises a long thin slotted port in front.

Here are our observations of the day :-

1. Matched with Diva M7 preamp and Cayin A-88T

Sound is quite full with a very nice tube bloom. Bass is weighty but slightly rounded. Transparency is quite good and this combination can entertain for hours, especially if you are into vocal and jazz discs

2. Matched with Diva M7 preamp and Hypex UCD400

Extremely fast sound with much tighter grip over the bottom end. Extremely detailed top end and the resolution is just incredible. The tube bloom is still there with just a hint of sweetness. Hi-fi mate declared this at the end of the session as the best sound of the day.

3. Matched with Copland CTA-401 integrated tube amp

My ageing Copland is one of the first few quality kit that I could afford. Taking me almost a year to save up for, I keep my Copland more for sentimental reasons than anything else.

Paired with the excellent Electro Harmonix 6CA7 tubes, the Copland puts out about 35 watts per channel in ultralinear mode. This is slightly less than the 45-50 watts put out by the Cayin A-88T which is based on KT88 tubes.

The Copland is noticeably slower and rounder than the Cayin. The Copland is an old school type of tube amp in that it provides a very liquid and luscious presentation. The Cayin is much faster and neutral in its midrange and top end in comparison.

Matched with the Thiel, I felt that the overall combination was a little bit too slow and did not highlight the strengths of the CS 1.6 well. Some may like its very romantic and rose tinted view of the world, but its sweetness does not match well with faster paced music.

4. Matched with Kingrex T-20U integrated T-amp

Hi-fi mate had to suspend dis-belief for a moment. Absolutely shocked at the volume that was achievable with the limited power on tap, he though the sound was overall quite good, especially considering the price. Overall, the combination is quite pleasant to listen to but is obviously not as resolving or controlled as the other two combinations above.

Combination 2 was heard with both my new Acoustic Zen Hologram II speaker cables and my existing Goertz AG-1 pure silver speaker cables. It was almost like a night and day difference in presentation. He found the Goertz forward and quite forceful in the way it "projected sound" (in his words), compared to the very gentle and refined presentation of the Acoustic Zen. He prepared the Acoustic Zen's presentation.

For some entertainment, we also hooked up the Kingrex to an old pair of Proac Tablette 50s. Obviously not quite as detailed as the Thiel, the combination was quite very enjoyable. Always musical, the Proac entertained well with its PRAT and sharp imaging ability.

Sadly, the session was so much fun that it ended far too soon. You can be sure that another session will be arranged soon.

Tuesday, October 6, 2009

Acoustic Zen Hologram II Speaker Cables

(Picture from official web site of Acoustic Zen)

Bought pre-owned from Audiogon, my new set of snakes arrived last month. After going through a overland trip from Florida to Oregon before being shipped by air to Singapore, these snakes are more well traveled than I am.

The AZ Hologram is a big thick cable finished in a handsome purple cover with light reflective mesh (so that it can remind me of its presence in my fairly dark listening room ?). My pair is finished in PCOCC gold plated copper spades on both ends with the speaker end split for bi-wiring.

The AZ is fairly flexible and despite its bulk, is quite tame and refrains from trying to pull equipment or speakers down from their perches. Wish I could say the same for the horrendously heavy PAD cables I have lying around somewhere.

Given its very heavy gauge, I was expecting the AZ to have a thick and heavy sound with bone crushing bass …… not. After a brief run-in, listening tests show that this cable is actually quite balanced but with a few strange characteristics that took me by surprise.

The first thing you notice is a perceived “drop” in loudness. The second is the rather distant presentation, almost as if you have been moved back from the front row to the mid section of the concert hall.

After some adjustment of the ears, you realize that the cable is extremely quiet. The apparent reduction in volume is a result of the bass which is tight but not particularly extended, and the high frequencies that are all there, but do not jump out at you. Extended listening reveals that the cable is very detailed with excellent low level resolution and microdetail. This is all very apparent due to a lack of grunge, sibilance and glare in the high frequencies. This enables the cable to sound smooth and non-fatiguing without throwing away detail.

Bass lines are neither thunderous nor weighty. In fact, the bass is extremely tight, but does not appear to go down deep. Coupled with the very refined high frequencies, this makes for an extremely refined and civilized cable that is well balanced from the bottom end to the top end.

Maybe as a result of its distant presentation, soundstage depth is incredible and deeper than anything else I have ever tried.

In comparison to the Goertz AG-1 cable that preceded the AZ, the AZ has very defined and clearly delineated image spaces. The Goertz has what local audiophiles term as “big-mouth” sound … ask a Cai Qin fan and he will know exactly how this sounds like. The Goertz has an extremely detailed feel to it, and much like the Acrolink cables I covered in an earlier post, the Goertz takes a health dose of artistic licence to texture the tone of instruments and the human voice. In contrast, the AZ is truthful and reflects the picture as it is.

The AZ is such a clean and balanced cable, that you wonder what the fuss is about. After taking the time to know it better, you realize that it communicates loads of detail in a coherent and balanced manner, without sounding harsh or introducing glare. All in all, this is a worth contender for systems that can showcase this cable (price wise, its definitely destined for entry level high end systems at the minimum).

Monday, September 21, 2009

Speaker filter

Original Post (September 2009)

Here are some pictures of my DIY speaker filter inspired by several threads on Audioasylum.

Very much like the Combak Enacom or the Walker High Definition Links, these are R-C networks or zobel networks that are applied in parallel across the speaker or the amplifer if you prefer (although they usually work better across speakers).

They will filter out ultrasonic garbage that happens to be in your system and their efficacy across the band depends on the value of capacitor and resistor that you use.

Why this project ? More out of necessity rather than vanity. The Alpha-Core Goertz speaker cables I use have much higher capacitance than average, enough to upset some amplifiers into oscillation. I thought I heard my AG1 speaker cables induce a hazy grain on the top end of my Hypex amplifier the other day. Maybe it was my imagination, but it was frightening enough to get this project up pronto. Zobel networks, besides their filtering effect also stabilises amplifiers.

Since this is a prototype project, I left this quite simple with a 10 nF and 1 nF cap, each in series with a 10 Ohm resistor.

It was really a surprise how much difference this simple device makes. There is a distinct clearing up of the sound, especially in the focus and articulation of the midrange. Vocals in particular sharpen in image size and the texture of the human voice becomes easily discernible. High frequency hash and the mess that happens when the recording mix becomes too heavy are cleaned up substantially by this.

Try it ! Its cheap, effective and really works.

Revisting the speaker filter - 4 years later (October 2013)

After a fair amount of experimentation using terminal blocks and spare capacitors, I made a second version of the speaker filter.

First off, the choice of capacitor is critical. The typical audiophile plastic foil capacitor does not work well here. I tried using a suitable value Multicap RTX and Vishay MKP 1837 but the results were underwhelming. Please stick to parts suitable for high frequency application like suppression caps, ceramic or silvered mica caps.

Secondly, it pays to utilise the other high quality parts and techniques recommended on Audioasylum, such as solid silver wire leads, and shielding the box - they really do make a difference. I am not sure whether the resistors make much difference, but I used 1% PRP resistors as recommended.

This filter sounds even clearer and more resolving that the initial set made. Soundstaging is particularly wide, and imaging is absolutely pinpoint. Go for this version if you can.

My audio buddy TC made a version using 3 stacks, i.e. 10 nF, 1nF and 0.1 nF but found it too dark. He removed the 0.1 nF capacitor and liked it a lot better.

Saturday, September 19, 2009

Kingrex T-20U

I have had the Kingrex T-20U for a few months now and so a post about this is long overdue.

The Kingrex has been around for sometime and has garnered a reputation for being one of the best sounding of the many low powered Tripath chip powered amps out there.

The designers of Kingrex must have paid careful attention to the many tricks that the DIY community were incorporating in Tripath amps as many of these tweaks and part changes can be found in the Kingrex such as :-

1. Film coupling caps
2. Premium air core inductors
3. Uprated low ESR local power supply caps
4. Heatsinked Tripath chip
5. Socketed op-amp for ease of opamp rolling (for the DAC only)

The icing on top of the cake is the Burr Brown PCM-2702E DAC with USB interface. Looks like this amp is clearly targetted at the PC audio crowd and you can say is perfect for powering small speakers on a computer desktop.

The T-20U is based on the Tripath TA-2020 chip which is capable of about 10-20 watts per channel into 4 Ohms (power varies depending on measured distortion level).

Rather than try to make this a detailed analysis of the circuit design and features of the T-20U, you would be better served to refer to the 6moons review on the T-20U at

I didn't plump out for the matching linear power supply (hi-fi has a mysterious way of emptying the wallet ... so it has to wait for the time being), so any observation on the sound is based on the supplied switching power supply provided.

The Kingrex sounds like most other Tripath based amps. Quite similar in balance to my Trends TA-10.1, the Kingrex has a weighty and slightly full bass. I prefer Tripath bass compared to Icepower bass which is extremely tight and extended, to the point that I find the bass too prominent, attention grabbing and somewhat unnatural.

The midrange and high frequencies are fairly neutral and the slight lack of depth in the midrange and air in the high frequencies differentiate the Kingrex from its much more expensive competitors.

I don't do PC audio, so I did not have a chance to evaluate its USB input and DAC.

Keep the load easy (stick to a speaker between 4-8 Ohms and sensitivity of at least 89 db/w/m or higher) and the Kingrex represents a good value amp with clean and musical output that belies its price tag.

Comparison with my modded Trends TA-10.1 were most interesting. My Trends amp is moderately modified, with the following changes made :-

1. Coupling caps changed from Bennic metalised polypropylene to Auricap
2. Stock volume control changed to Panasonic miniature pot
3. Inductors shielded with copper
4. PCB tracks cut for direct wiring from RCA input to pot and back to coupling caps

The Trends was clearly better in every aspect and was also much cheaper to start off with. Sound was clearer and more coherent with low level resolution superior to the Kingrex.

I don't think this means that the Kingrex is a bad buy. However, it indicates that a stock standard T-amp (check out the many cheap T-amps on ebay nowadays) is capable of performing just as well, or even better than the Kingrex with some judicious modding.

The Kingrex is therefore suitable for the audiophile who does not have the desire or ability to mod the unit, or one who attaches a premium to the professional finished look of the Kingrex.

Thursday, September 17, 2009

Diva Audio M7 Preamp - Latest update

For all you Diva Audio M7 users out there, T.S. Lim has just revised his flagship M7 preamp.

The latest revision combines two stages of modifications.

The first stage involves new voltage supply filtering on both the B+ and the heater, combined with star ground wiring arrangement.

The second stage is a rewiring of the tube arrangement to allow easier tube rolling, and the installation of a new internal bracket that allows higher quality smoothing capacitors to be installed.

More on the tube rolling - previously the tube stages in the M7 are arranged as follows, the bottom tube uses one triode (the 12ax7 is a dual triode) as first stage, and the other triode as the second stage of the left channel. The top tube is identical and is used for the right channel. This then passes through the third stage in the middle tube (one triode for each channel). This means that you can only roll two different type of tubes at the most since the first and second stage use the same tube.

The M7 is now wired with each stage using one triode in the tube, i.e. the bottom tube is the first stage, the middle tube is the second stage and the top tube is the third stage. Now you can roll tubes to your heart's content.

Anyway, enough talk about the technicals. How does it sound ? I only managed to put in an hour of listening before sleeping but here are my initial thoughts on the latest incarnation of the M7 :-

1. Resolution - There is a noticeable increase in low level resolution and background "blackness". For example, on guitar notes, you can hear more of the body resonance of the guitar instead of just the plucked strings. Even in loud and complex passages, the increased level of detail is obvious.

2. Bass - Bass is substantial with more depth and extension.

3. Soundstaging - More 3D like with an noticeable increased in soundstage depth. Image sizes also are slightly larger.

4. Dynamics - The dynamic contrast between the loudest and softest passages is increased. Interestingly even at very high volumes, the dynamics are realistic and never fatiguing.

Note that my M7 uses a vintage military choke and NOS silver plated internal wiring. The volume pot is the standard Alps blue model though.

Oh yes, most importantly, T.S. Lim is offering this upgrade to existing M7 users for S$ 700. If you have already done the voltage filter and star ground, then the cost is S$300.

If you take this as an unreserved recommendation to upgrade your M7, you are not wrong. I highly recommend this upgrade. In current times when sought after NOS 12AX7 has reached silly money levels, this is money well spent.

Thursday, August 13, 2009

Acrolink 2070II

The Acrolink 2070II is the junior member of the 7N interconnect range of Acrolink of Japan.

I had earlier written about the 2400II which is the top of the range of the 6N interconnect range. An opportunity arose to acquire the 2070II at a decent price and I took it without hesitation. I have actually heard the 2070II before briefly at Audio Basic in Adelphi but did not want to consider it due to its considerable expense.

Physically, the 2070II and 2400II are quite similar in that they have a transparent outer insulation layer which shows off a metal braid shield underneath. Both utilize extremely bad and mean (I mean that in a complimentary way) looking RCA plugs that looks like they can be worn as hi-fi bling bling. Sporting carbon fiber bodies and rhodium plated pins, they certainly look the price and exude class.

The 2070II is physically larger and substantially heavier than the 2400II and its RCA plugs are quite large (and actually too close for comfort on tightly spaced RCA sockets). Owners of light weight T-amps beware, your cable will probably end up pulling down the amp if you are not careful. To its credit, the cable itself is relatively flexible. On an utterly trivial and sonically unimportant note, the 2070II comes is a beautiful wood presentation box that was stunning enough to lead my partner to hint that the box was perfect to store her jewelry in.

If you refer to my earlier posts, Acrolink cables have a house sound. Generally detailed, they have extended high frequencies and an overall airy feel to them. The 2070II does not disappoint in this respect. The 2070II differs from the 2400II in the following areas,

1. Bass – Most of the Acrolink cables I have heard are bass light or appear to be bass light due to their emphasis on the high frequency end. The 2070II does not suffer from this at all and has firm and tight bass with appreciable heft compared to the 2400II.

2. Midrange – The 2070II has less forward midrange projection compared to the 2400II. It sounds more mellow in comparison. Also, the midrange has a highly textured feel to it with fine nuances and changes in timbre clearly audible. The 2400II is like sitting a few rows closer with the midrange more 2-D like.

3. Treble – No surprises here. The 2070II continues in the Acrolink tradition of delivering the most beautiful shimmering highs with excellent communication of acoustic space of instruments and the venue. The extra expense here gets you even more refined treble with composure even in the most complex of mixes.

One interesting characteristic of the 2070II is the absolute blackness and quietness of the cable, as well as the sheer amount of micro-detail available. The 2070II in my humble opinion is a significant upgrade over the 2400II although it is quite obviously intended only for fairly high end set-ups given its cost. I like this cable very much. One reservation I have in general is that there is a nagging feel that what is being conveyed is not the truth, but rather than the manufacturer’s artistic impression on what music should sound like. Seriously though, if its artistic viewpoint is this much fun and musically satisfying, why not ?

Friday, July 17, 2009

B&W 804S Floorstanding Speakers

I recently had the opportunity to build a system around the B&W 804S for a non-audiophile family setting up their first serious system.

They were brought around to audition a number of speakers, before they settled for the B&W.

For those unfamiliar with the B&W 804S, it is the smallest (its actually quite big physically) floorstanding speaker in B&W's 800 series line-up. At approximately double the price of the stand mount 805, the 804 has 4 drivers in a boat shaped cabinet with front firing port. Its a 3 way design with a Nautilus tweeter mounted on top of the cabinet.

On the rear, bi-wiring terminals are provided and jumper cables (not stupid brass links) with one end intelligently terminated with spades and the other with banana plugs, thereby ensuring compatability with cables terminated with either spade or banana plugs. Why can't all manufacturers do this ?

The B&W was heard twice in two different dealers. Pairing equipment included an all Arcam setup, Classe amplification and CD players and an all Cyrus setup. The B&W sounded very different through each of the three systems set up for demonstration purposes, suggesting that it is quite sensitive to matching with partnering equipment. Tonal balance wise, it managed to sound bright and fast with one setup and rich and somewhat slow on another.

Eventually, the 804 was paired with a Bel Canto S-300i. The combination is quite nice with very good grip and control over the lower registers and a neutral midrange tonal balance. The high frequencies manages to be extended with a fair bit of sparkle coupled with slightly rich bass. So who says your speaker can't sound clear and clean, while being weighty too ?

The B&W is versatile enough to handle varied music types with aplomb. Classical works, female vocals, jazz, rock and pop doesn't faze the 804 one bit. What I like about the 804 is that the presentation is not overly analytical. It doesn't stress out the owner by limiting him to a diet of audiophile recordings. Neither is it so non transparent that good ancillaries are wasted on it. A speaker of all seasons, it has enough qualities to please the hard core audiophile while being easy going enough to suit the casual listener.

One issue though is the local pricing in Singapore. This speaker retails for more than USD 5,000 (at today's exchange rates of about SGD 1.46 to USD 1.00) which puts it in serious speaker territory. There is a lot of quality competition at that price range, some of which are to my ears preferable to me compared to the 804. But I do digress. The 804 still warrants serious consideration, so do check it out if its in your budget range.

Monday, June 29, 2009

Bel Canto S-300i integrated amplifier

The Bel Canto S-300i is a handsome piece of hear. Sporting arguably the thickest aluminum fascia I've ever seen, the fit and finish is absolutely stunning. From the tactile feel of its microprocessor controlled control knob, to the WBT binding speaker binding posts, everything feels perfectly balanced.

For a "digital" amplifier, the Bel Canto is also suprisingly heavy, about 5 kg. Based on a 150 wpc (8 Ohm) Bang & Olufsen Icepower module, the Bel Canto will deliver up to 300 wpc into a 4 ohm load.

Well enough about the specifications, how does it sound ?

According to conventional hi-fi wisdom, "Digital" amplifiers sound dry, synthetic and lifeless. Some early "digital" amplifier designs may have done nothing to dispel that myth. However, the Bel Canto has a fairly easy going sound. Extremely tight and fast bass, a warm midrange with the right amount of weight, what more could one ask for ?

I think the weakness of the Bel Canto lies in its presentation of high frequencies. There is a certain opacity and dryness to the sound such that hi-hats and percussion instruments don't really have much sense of air or space. You can hear the initial transient of the note, but without much feel of the decay thereafter. This weakness is not immediately noticeable but is revealed upon extended listening and comparisons with the other amplifiers I had at hand.

The above criticism has to be taken in context. The Bel Canto for its power is not an expensive amplifier (OK, its not a budget amplifier either). It proved very reliable in use, never skipping a beat or giving any cause for concern. I have built two systems around this amplifier for friends, and the results have been very satisfying. However, its overall balance requires careful auditioning and matching with partnering equipment.

Saturday, June 13, 2009

An Afternoon of Tuning

Saturday afternoon was spent over at a friend's place listening to his newly built Fostex FE168 Sigma in backloaded horn cabinets and the Diva Classic 1L preamp.

My friend has the honour of owning the very first set of the 1L preamp fresh from T.S. Lim's hands.

The Diva was paired with a modded Cayin A-50T. The Cayin does not have a direct preamp in socket, so the volume knob was either turned to maximum or about 12 o'clock (at times we felt the gain was too high with the knob at maximum). The Cayin is basically a power amp with a passive preamp stage inside a single chassis.

The modifications done to the Cayin A-50T include a change of input coupling capacitors to Jensen aluminum paper-in-oil capacitors. The other coupling caps downstream were changed to Sonic Cap MkI and the feedback caps changed to Solen. The grid stopper resistor has also been changed to Japanese Kiwame resistors.

The 1L has a beautiful yellow faceplate and uses an outboard solid state rectified power supply. The preamp circuit should be very simple (we didn't open it up) since there is only a single 6SN7 tube.

The Fostex was still running in, and we felt that although the tonal balance is quite nice, there was no bass, and very limited high frequency extension. Midrange definition also lacked some texture. Probably more extended run in would be needed before final conclusions could be made.

The full range driver strengths in terms of dynamics and coherence were all there, just that the lack of frequency extremes (this Fostex driver has no whizzer cone BTW and has an intriguing flower like pattern on its cone) and slight shoutiness made the sound a bit uneven.

First up, we rolled some of the tubes. The first to go were the small tubes in the Cayin. The 12AX7 and 12AU7 used there were JJ 12AX7/ECC803 and stock Cayin 12AU7 (almost certainly Shuguang). The 12AX7 tubes were replaced with RCA 5751 double mica blackplates and the 12AU7 replaced with RCA cleartops.

Flick the switch and hummmmmmmmm. Oops. Turned out the 5751 tubes were being a bit naughty. So, the JJs went back in. Wow, what a world of difference just with the change of 12AU7 tubes. Midrange was much more defined and the overall feel was more lifelike, focused and textured.

Other adjustments done included replacing the EL34 tubes of the Cayin with EH6CA7 tubes, and the stock EH 6SN7 in the Classic 1L which was replaced with a RCA GTB blackplate. Speakers were moved out a bit and toed in almost directly to the listener.

Ah... so much better now, although we both agreed that the very creamy and rich sound of the RCA 6SN7 GTB may be a bit too slow and warm for some.

My friend suggested we try the setup with another pair of speakers, Totem Sttaffs. Turned out to be the best sound of the day, but only with judicious repositioning of the speakers in the room.

The speakers were brought out far into the room and with slight toe in aiming to a point behind the listener position.

The bass was still slightly uncontrolled and a pair of socks had to be sacrificed to block the rear-firing ports of the cabinet.

Actually we had both written off the Totem Sttaffs before this point as my friend had quite a lot of problems with the Totem that sounded very dark with soundstaging and imaging problems. But he is now keen of keeping the Totem and fine tuning it to get the best sound possible.

It was a very fun two hours and we both learnt quite a fair bit. The tube rolling was quite a shock for both of us. Although I have always been a proponent of NOS preamp tubes, this is the first time I have heard such a day and night difference with just a single tube roll.

It will be interesting to see how the Fostex turns out after another 50 to 100 hours of run in.

Wednesday, April 15, 2009

Acrolink 6N Interconnects - Quick comparisons

Acrolink 6N-A2400II

How much did I pay for this interconnect ? I am somewhat embarrassed to say. On the lookout for an upgrade from the Acrolink A-2110, looking at one of its higher end brethren seemed like a logical choice.

Speaking to the ever helpful Steven Cheah of Audio Basic in Adelphi, he suggested looking at the Acrolink 6N A-2400II. Residing at the top end of Acrolink’s 6N range, it is more than double the cost of the Acrolink A-2110.

Was anything wrong with my A-2110 ? Not really. It was enough to impress me in listening tests to warrant a purchase. And having listened to the whole gamut of cable out there from DIY Belden and Klotz to Audioquest, Mogami, XLO, Crystal, Siltech, that counted for something.

The A-2110 is a rather plain looking cable with a nude colour outer sheath terminated with very nice Acrolink RCA plugs. During listening tests when I first bought it, it quickly distinguished itself compared to the A-2050 II and A-2200 II which are the entry level models in Acrolink’s line-up. You can refer to for more information.

The A-2400II in comparison is a very impressive looking cable with a transparent gold insulating jacket, with the braided shield underneath quite visible. The RCA plugs in particular are a work of art. They are heavy, well made, and are rhodium plated. Part of the barrel is made out of carbon fiber. Full specifications are available at

The A-2110 has the characteristic Acrolink house sound – light, delicate with emphasis on a neutral midrange and shimmering highs, with very natural air around instruments and decay from transients. If the A-2110 had one drawback, it was the relative lack of bass compared to its sparkling highs.

Anyway, it was decided at Audio Basic that we would not test cables beyond the A-2400II simply because I was not willing to spend that much money on wire. A selection of tracks from Eva Cassidy’s Live at the Blues Alley were selected for comparison purposes.

By the end of the comparison, it was evident that the extra money had to be spent on the A-2400II. In fact, the miser in me had hoped that the A-2110 would prove more than sufficient. The A-2400II strikes you immediately as being a very quiet cable with absolute control over both ends of the frequency spectrum. Initially, it appears to be less dynamic than the A-2110. Further inspection reveals that the dynamics of the A-2110 are partly due to the slight messiness of its presentation. The crash of cymbals etc and resonance from percussive instruments can be slightly smeared in comparison. Also, when things really got busy, the A-2110 had a tendency for instruments to get lost in the mix.

As a matter of interest, my non-audiophile partner was asked to listen to 6 different interconnects. She commented on how similar the A-2110 and A-2400II were in terms of balance, although she had a preference for the A-2400II which in her words was simply better.

It was nice to see that diminishing returns did not set in for the A-2400II and the money spent was justified as compared to spending the extra dosh on upgrading other components in the system. IMHO, the expense of the A-2400II is fully justifiable in high end set-ups, where it is really able to strut its stuff.

As a matter of interest, I acquired a second hand A-2200II recently for another set-up. It is darker sounding than the A-2110 and has less treble refinement and extension. For that reason alone, I preferred the A-2110 which is more suitable in my setup.

A year or two after originally writing this post, I managed to get hold of the entry level 7N model, the A-2070 (please see my separate post on this). The bottom line for Acrolink is that you get what you pay for, with a corresponding increase in resolution, refinement and bass quality as you go up the range.

Sunday, April 12, 2009

Hypex UCD400

Over the past few years, I've dabbled with a number of "digital" amps (they actually aren't digital, but that's a whole separate discussion) and have had positive experiences with some of them to consider them seriously for a permanent place in my hi-fi systems.

I remember my first experience, the first generation Sonic Impact amp based on a Tripath chip with 5W output. The gasp that came from the small group that had gathered at my house was not really related to the sound, but more the shock that the tiny little amp could drive my Monitor Audio bookshelf speakers, powered by 8 AA batteries no less !

Fast forward, and I've tried a number of technologies including Tripath, proprietory (Flying Mole), B&O Icepower and now Hypex.

The Hypex was purchased second hand through a local hi-fi forum and was assembled by local modder and DIY supplier, James from Effective Audio Mod.

Here are some photos including some a shot under the hood. As you can see, it is a dual mono design with separate transformers and power supply boards for each channel. There is a motorised Alps potentiometer in front with a toggle switch, so you can use it as an integrated amp or power amp.

Sound wise, the Hypex seems to stray from the path of the sonic balance of most "digital" amps in that it avoids having the subterranean bass that seems quite common for these powerhouses. In fact, the sound of Hypex reminds me very much of the sonic balance of Tripath based amps.

The bass is quite well rounded with a certain amount of fullness (reminds me a bit of my tube amps ... of course my tube amps have much less control in the bass region). Its midrange is quite neutral with this balance maintained up to the high frequencies.

Amongst all the "digital" amps I've owned or heard, this one has the most pleasing highs. It doesn't sound etched, or dry. There is a nice sparkle and the communication of acoustic space is excellent. When listening to Patricia Barber's excellent drummer, the way the high hats shimmer is absolutely sublime. In case you think I really like this amp .... I do !

The above is with the built in passive potentiometer (Alps blue velvet). Paired with a Diva M7 tube preamp, the midrange becomes slightly fuller with the high frequency maintaining their shimmer but losing a bit of separation in favour of a slightly more organic presentation.

I also found that the Hypex matched very well with my Thiel CS 1.6. It had just the right balance to warm up the bass while maintaining the Thiel's neutrality and speed in the midrange and treble. What if you can't afford the Hypex ? Think seriously about a Tripath amp if you can get away with its power limitations. I have a Kingrex T-10U that I'll write about soon.

Saturday, March 28, 2009

Quick and dirty comparison of 12AX7 and compatible tubes

Here is a quick comparison of 12AX7 and 5751 tubes in my Diva Audio M7 tube pre-amp.

For those unfamiliar with the Diva Audio M7, it is a fairly popular tube pre-amp designed and built in Singapore by Mr. T.S. Lim. It is based on the Marantz 7 circuit and uses 3 12AX7 tubes.

Here are the observations of rolling the first tube position. Electroharmonix 12AX7 gold is used in the second tube position while the RCA 5751 blackplate (double mica) is used in the third tube position,

1. GE JAN 12AX7WA (1986 date code)

The tonal balance is dense with decent midrange and treble detail. However, dynamics seem a bit flat.

2. Golden Dragon 12AX7

The tonal balance is lightweight. A bit of a paradox, but the tube avoids brightness despite quite a lot of treble extension. Midrange and treble seemed smoothed out but the highs seem to go a lot further. I say it it a paradox to me, because this kind of extended response usually results in a fairly bright presentation. The lightweight sound probably comes from the lack of bass. This tube was a lot better than what I expected.

3. Sylvania 5751 gold pin (tripe mica)

My favourite tube of the lot. A lot of detail with both extended bass and treble. Very good air with good control of sibilance. Tonal balance is close to neutral.

4. RCA 5751 blackplate (double mica)

Dark tonal balance. Very smooth and creamy but compared to the other tubes, some midrange and treble detail is lost. I suppose its quite ideal in bright systems, but match with care. That being said, I've had very good results for this tube in other equipment.

Sunday, February 15, 2009

Anthony Gallo speakers

I had an opportunity to audition Anthony Gallo speakers at the local dealer recently, having been tasked to help a friend set-up a home theater system. Having an unobtrusive and stylish design was important, so the cute little spheres from Anthony Gallo seemed to be worth checking out.

The local dealer is econ-av and they have a small showroom on the first floor of Adelphi Shopping Center. You can have a look at to see the full range of Anthony Gallo.

I auditioned the Nucleus Micro, Micro Ti and the A'Diva Ti. The setup used for the Nucleus Micro and the rest were different (the Nucleus Micro was ceiling mounted) so comparisons may be due to mounting.

All 3 setups were auditioned with both hometheater and music.

First up was the Nucleus Micro. Based on looks alone, I would have chosen this. The cute little spheres come in very funky colors including bronze, glossy red and yellow.

As all 5 channels use identical spheres, steering is excellent with the panning between channels being seamless. Imaging is also quite good. Surprisingly the speakers sound more than decent with music and seem to go fairly low for their size (I estimate about 100 Hz). The dealer switched off the subwoofer and they actually sounded quite OK.

We switched over to the Nucleus Micro Ti. I didn't like it and it sounded too forward, crispy (not in a good way) with a noticeable tilt at the top end.

Finally, we listened to the A'Diva Ti. Very nice. Much of the quality of the Nucleus Micro while showing a noticeable improvement in weight and extension (the A'Diva is physically larger).

One thing I noticed is that the center channel sounds very small in comparison. Having listened to multiple driver center speakers my whole life, the dialogue seems in comparison to be less "centered" to the screen and lacking in depth. Having said that, I seldom hear conventional home theater speaker sets with such even panning from left to right.

Finally comes the sticker shock. These cute speakers sell for $2,000 for the 5.1 set (Nucleus Micro in plain finishes). Extra for exotic finishes. The Nucleus Micro is $2,800 while the A'Diva is $3,800. The matching subwoofers included in this package seem a bit small and it may make sense to pair the satellites with another active sub.

Pity. They really are cute and perform competently. The large markup over the U.S. price will make them hard to swallow for the local audiophile / videophile. Worth checking out if aesthetics are very important to you and you don't mind the premium.

There is an interesting product which looks quite similar from Orb Audio ( which are priced more competitively. They are only available direct over the internet so comparisons will be difficult.