Sunday, May 27, 2012

Acrolink 7N-S1000III and 7N-S1400III Speaker Cable


The Acrolink 7N-S1000III and 7N S-1400III are part of Acrolink's new line up of cables for 2011, and also an introduction of 7N purity copper into their lower range of cabling.

Utilising similar geometry to their predecessors, the S-1000 / S-1400 have two widely spaced conductors in a flat shaped dielectric. Looking at the design, this will most likely result in fairly high inductance but very low capacitance.

The main difference between the S-1000 and S-1400 is conductor gauge, the S-1400 having more than double the number of strands of copper in each conductor leg.

S-1000III - Picture from official website

S-1400III - Picture from official website

Sound Quality

Acrolink users are unlikely to encounter any surprises here. Great midrange, with excellent high frequency extension and control, with emphasis on the "air" around instruments and the sense of acoustic space.

The S-1000III subjectively sounds faster than the S-1400III. The latter has a harmonically rich mid-bass and fuller human voice. Image sizes are also larger compared to the S-1000III which is more pin point. On female vocals in particular, sibilance is well handled by the S-1400III, which has a smoothness that tends to reduce sibilance.

In terms of setup, the S-1000III is easier to match partnering equipment in most setups. Care is needed with the S-1400III to avoid a loss of speed and excessive mid-bass.

I never had the 6N S-1000II in my setup, but based on the S-1400, the change from 6N to 7N conductors brings about improvement in micro detail, high frequency extension and control. Otherwise, the cables are more an evolution than a revolution in character.


A word of warning on termination. I bought the S-1400III pre-owned. The previous owner had terminated it in gold banana plugs (the manufacturer of which shall remain un-named). I thought that the cable sounded rythmically slow and overly warm. High frequency detail and extension were also obscured compared to the S-1000III and even my old set of 6N S-1400II.

Re-terminating the connections with Oyaide spade (SPSL) and banana plugs (SRBN) brought speed and clarity back to the cable. The SPSL spades are made of brass, and plated with silver, followed by platinum. The SRBN are also made of brass, but plated with silver, followed by rhodium.

The only other experience I had with dramatic differences in termination, was with the Mogami 2803, which greatly favoured Eichmann Bullet Plugs over other quality terminations like the Neutrik Pro-Fi.

So folks, please pay attention to your terminations for this cable.


The 7N series is a great upgrade for existing users of the older 6N series. If you are new to the Acrolink line, a trial before purchase is warranted as the balance and character may not be for everyone.

Monday, May 14, 2012

Footer shootout - The Good, the Bad and the Ugly (Revised on 4 Nov 2014)

On test here are the following gunslingers,

1. Aurio's Classic
2. Cold Rays
3. Finite Elemente Ceraball Universal
4. Finite Elemente Cerabase Classic
5. Finite Elemente Cerabase Compact 
6. Franc Audio Ceramic Disc Classic
7. Golden Sound's DH Cones and Squares
8. Herbie's Tenderfoot
9. Herbie's Isocup with Black Lamp Ball
10. Kryna C-PROP Mini / D-PROP Mini
11. Magic Hexa
12. Stillpoints Ultra Mini
13. Stillpoints Ultra SS (New) 
15. Valab ball bearing footer
16. Yamamoto Sound Craft PB-09 / PB-10 Ebony base

Aurios Classic

Unlike its namesake, the Aurios cannot be dunked in milk, or eaten. But like Oreo cookies, the Aurios are made out of two circular halves, with the goodstuff in between. 3 steel ball bearings take the place of the sweetened white cream in the cookie version.The steel bearings sit in a circular race, with a plastic triangular guide to hold the 3 ball bearings in place.

Out of all the devices featured here, the Aurios have the dubious honour of being the most unstable. Components are able to roll around a fair bit, and I’ve had to dive to save some equipment when I placed the Aurios a bit too close for comfort near the perimeter of the equipment’s chassis. This does pose a problem if you place it under a CD player, as pushing buttons results in a bit of wobbly jelly effect, although the problem is less noticeable under heavy equipment.

The Aurios are very extended at both ends of the frequency spectrum. Bass is superbly tight and defined, and ambience retrieval at the top end is outstanding. Overall, the sound takes on a very projected and focussed quality. Its fly in the ointment is its high frequency quality, which can be artificial and fatiguing. Separation and control is also a bit lacking with cymbal work sounding a bit messy. The other ball bearing footers on test here, the Cold Rays and the Ceraball have both extension and better control.

Cold Rays

This is a ball bearing footer with a difference. The Cold Ray features a bell shaped top that sits on top of a ball bearing (you have a choice of either a steel or ceramic ball - the on test here is the ceramic ball version). The lower assembly is a solid flat topped cone. The manufacturer claims that the bell shaped top acts as a resonator and limits the amount of vibration that can pass through the footer.

In terms of physical stability, the Cold Ray is most comfortable under heavy loads. With its high center of gravity, the Cold Rays were not stable under lighter equipment. Of other notable interest is that the Cold Rays are the only footer in my system that sounds better with a quartet deployed. This makes levelling the footers a bit difficult, but nothing that cannot be fixed with a bit of 3M post it notes.

Using the Cold Ray can be a bit of a hit-and-miss affair. It did not work well under my tube amp, or DAC, but was great under my Cary CD Player. Balanced throughout the frequency spectrum, it had excellent definition, extension and control. Instrument separation and composure under heavy mixes were outstanding.

Honourable mention should go towards the sense of extension brought by the Cold Ray. It avoids sounding artificial, and has both speed, and natural decay and reverb - which cannot be said for some of the other footers on test here. When it works, the Cold Rays are one of the most impressive footers in this shoot-out.

Finite Elemente Ceraball Universal

A regularly recommended ball bearing footer, the Ceraball from Finite Elemente of Germany is probably one of the most well-known of its breed. Finite Elemente has a whole range of footers based on ball bearing support, including some mean footers that are probably strong enough to support the weight of a very large sized sumo wrestler.

Each model in the Finite Elemente range is suited for a specified range of loads. The Ceraball is the smallest model in their line-up and is suitable for lighter components although each individual footer is able to support up to 40 kg of load. The next model up, the Cerapuc is also a single ball bearing model but designed for heavier loads. The top model, the Cerabase utilises 3 ball bearings. As the name suggests, the ball bearings used in all of Finite Elemente's footers are ceramic. The Ceraball is made of aluminum while its bigger siblings are made of stainless steel.

The Ceraball brings immediate focus and solidity to music. Besides tightening up the bass, midrange becomes clearer. High frequencies are neater also and more extended. Improvements in both transient attack and decay are observed. Compared to the Cold Rays, the Ceraball is drier, with less bloom and weight.

I also had a trio of the top range Cerabase on hand for comparison. The Cerabase has greater potential than the Ceraball. It outperforms the Ceraball but only under heavier loads (in excess of 20 kg). Used under my Cary CD-500 (10 kg load) , its performance was close to its cheaper sibling.

The Cold Rays have greater potential, but the Ceraball delivers more consistent results across a variety of equipment.

In liberal doses, the Ceraball can sound too sharp and clinical. In my system, I usually use no more than one set in a a system.

Finite Elemente Cerabase Classic

The Cerabase Classic is the bigger and meaner version of the Ceraball. The Cerabase is made from stainless steel and uses 3 ceramic balls. It has an optimum weight loading of between 40 to 500 kg of weight (125 kg per footer). The Cerabase Classic is height adjustable which is essential if you are using 4 footers.

The packaging is very comprehensive, including provision of various threaded bolts to allow the Cerabase to replace your stock spike underneath your speakers or equipment rack.

Sound wise, the Cerabase Classic sounds like a grown-up version of the Ceraball, with additional focus, separation and refinement.

Finite Elemente Cerabase Compact

The Cerabase compact is similar to the Cerabase Classic, with a stainless steel assembly and 3 ceramic balls. It has a smaller base, and is shorter. This is useful for large components with limited height clearance.Optimal weight loading is from 20 kg to 150 kg weight. My Conrad Johnson power amp despite being close to 20 kg in weight sounded better on the Cerabase Classic compared to the Cerabase Compact. The house sound is there, but the Compact sounds slightly brighter than the Classic, with slightly less bass and a midrange that is a touch more forward.

Franc Audio Ceramic Disc Classic

The Franc Audio Ceramic Disc Classic is a relatively new offering from a young Polish company. It is mechanically quite complex with a top disc with a firm elastomer surface that makes direct contact with the component. The disc in turn is coupled to a single 8mm ceramic ball that rests on a three point holder. Internally, the 8 mm ceramic ball is coupled to an aluminum disc that in turn rests on three 6 mm ceramic balls. The internal construction is quite complex and deserves a separate write-up.

Compared to the Cerabase, the Franc Audio offers a smoother midrange and more organic sounding bass lines. However, separation and focus are as good as the Cerabase. Slightly richer and more "wet" sounding than the Cerabase, the Franc is perfect for those who want detail but a richer and more fluid presentation. Tonality wise, it reminds me of a bigger sounding version of the Stillpoints Ultra Mini.

Golden Sound DH Cones / Squares

An oldie but goodie, the Golden Sound DH Cones / Squares are made from near diamond hardness (hence the name “DH”) ceramic and a graphite composite material respectively.

They can be used separately, but are claimed by the manufacturer to work best together.

You have to experiment with them facing upwards or downwards. I’ve found that using 3 cones almost always works better than 4. They are available in a variety of sizes, but my personal collection consists of the larger sizes, i.e. jumbo and super.

The DH Cones / Squares have in the past served me well under tube amplifiers. However, during tests, they failed to perform under the Calyx 24/192 DAC, sounding thin and confused.

Used under the Cary CD-500, the cones alone resulted in a forward sound, with voices moved closer towards the listener. There were gains in midrange coherence and high end extension. But the bass took on a lean and rhythmically disconnected feel. In the long run, I found the high frequency extension to be metallic and fatiguing. Pairing the cones with the pads brought everything together in harmony. The metallic sheen disappeared and bass bloom and warmth were restored. 

As a combination, the DH Cones / Squares bring gains across the frequency range. They are system dependent and do not work well with lighter equipment.Although they work well when optimised, they are comfortably outperformed by the Ceraball and Cold Rays.

Herbie's Tenderfoot

The Tenderfoot is a square shaped footer made out of a silicon based elastomer formulation. The model here is made out of the older white coloured material. The current model is black in colour.

The Tenderfoot lends a nice roundness and density to the bass and midrange. It generally leaves the top end intact, and does little to add focus and improve microdetail. It is a fairly average performer, which is in line with its low price.

Nothing particularly offensive about the Tenderfoot, but little to write home about either. Its bigger sibling, the Isocup is a much better performer.

Herbie's Isocup with Black Lamp Ball

The Isocup is a circular shaped footer with a concave depression in the center (much like an egg cup), in which sits a matching one inch diameter ball. It used to be available with a variety of ball options, but the current offering is limited to a "Supersonic Hardball".

Equipment does have a tendency to slide a bit with the Isocup. The manufacturer recommends a bit of liquid silicon gasket maker underneath the equipment at point of contact to stop the sliding.

Contrary to my experience with compliant and squishy footers which can sound muffled and slow, the Isocup is bold and vibrant sounding. The Isocup has good dynamics and bass is both more extended and more pronounced. Midrange is smooth but also quite laidback. The Isocup also has modest improvement in high frequency extension. Decent gains are also observed in separation between instruments.

Kryna C-PROP mini / D-PROP mini

A rather interesting footer from Japan, the Kryna is unique in featuring a silicon fluid damped spike resting in a sealed housing. The D-PROP is based on a double metal spike, while the C-PROP is based on a single metal spike in a plastic housing.

Both the D-PROP and C-PROP are sold individually and can be mixed and matched according to your liking. The brochure (only in Japanese) suggests a number of placement configurations based on typical applications. Being unable to read Japanese, I also spoke to the distributor and the instructions seem to suggest use of either the D-PROP or C-PROP depending on whether the footer is being asked to absorb vibration within the component (e.g. transformers, motor spindles), or to prevent shelf vibrations from reaching the component. The D-PROP is suggested to tackle the former, and the C-PROP, the latter.

The brochure I took from a shop in Japan suggests various combinations of the C-PROP and D-PROP under different types of equipment.

Used under my DAC, the Kryna has a refined sound that is quite different from the rest of the footers here. It  has a clear sound that avoids the razor sharp focus of some of its competitors. Initially it sounds somewhat soft, but over long term listening, it becomes obvious that it trades a bit of impact and leading edge definition for body and smoothness. Listeners who find cones and spikes too "sharp" sounding, and compliant footers too slow and mushy would probably like the Kryna - it takes the middle ground between the two.

Magic Hexa

I generally don't like squishy products, but the Magic Hexa is quite firm and large (76mm in diameter and 23mm tall). The honeycomb structure flexes very little when placed under moderate loads (each single disc is rated for a maximum of 12 kg) and its anti-skid surface makes placement easy and fuss-free.

Sound wise, the Magic Hexa adds a good level of focus and increase in resolution. It manages to do this without adding any softness or reduced dynamics. It is also very affordably priced (S$85 for 4). I especially like the fact that the disc is so large that I can use a single piece for brick power supplies and the like. It is by no means the best performer on test but easily the best value for money item.

Stillpoints Ultra Mini

The Stillpoints utilise multiple tiers of ceramic balls inside a sealed housing. They offer moderate height adjustment which is extremely useful when trying to level four cones under equipment.

They are highly sensitive to placement, and it took me months to find an ideal placement under my Conrad Johnson preamp. When used correctly, they offer a marked increase in focus and clarity. Unlike most ball bearing devices, the Stillpoints sound smooth and warm on the top end.

Stillpoints Ultra SS

This is larger version of the Ultra Mini. I found them easier to place compared to the Ultra Mini. Think of it as an even more refined and higher performing version of the Ultra Mini. The price tag is on the wallet unfriendly side though.


Easily the heaviest amongst all the footers on test here, the TAOC weighs a massive 800g per piece. TAOC specialises in the manufacture of high carbon content cast iron parts, and is actually a member of the Toyota group. You could end up in hospital if you accidentally dropped one on your foot.

The TAOC served as a brutal reminder on the perils of hasty judgement and "settling time" for footers.

Quick insertion brought bone crunching bass and slam, with increased separation and control, at the expense of a lack of high frequency extension and air. After a few days of settling time, this went away, and the high frequencies took on both extension and control. This was particularly noticeable during heavy mixes, where previously blurred lines and messy details took on organised precision. The TAOC lacks the ultimate 3D quality and natural ease of the Cold Rays but was otherwise very impressive.

If you are looking for a "jump" factor, these footers are likely to please provided that you give them plenty of time to settle down..

Valab footer

Looking very much inspired by the Finite Elemente’s Ceraball, this footer from Valab, Taiwan, similarly relies on a single ball bearing, albeit steel. Fit and finish are not exactly the best, the prime offender being a rubber O-ring that is a little bit too big. As a result, the top cover of the Valab will not sit tight against the ball bearing unless the component is of sufficient mass to compress the O-ring.

Is this a cheap and cheerful clone, or just cheap and nasty ?

The Valab adds some clarity to the music, and has nice improvement to the high-frequencies, which are more distinct, and more extended. On the downside, the overall presentation is quite dry.

The midrange and low frequencies are where the Valab comes apart. Bass notes are lightweight and hollow, compared to stock. Midrange is small sounding and lacking in density.

Taking out the Valab and substituting it with the Ceraball shows that the Valab may be much cheaper, but is actually false economy. Valab may want to go back to the drawing board and take another shot at this.

Yamamoto Soundcraft Ebony footers

Yamamoto Soundcraft is not particularly well-known outside of Japan, although there is some limited distribution of their products globally, especially their amplifiers. They have an intriguing range of footers, ranging from simple cherry wood cubes, to their top-of-the-range magnetic levitation bases.

Their rather modest ebony footers are in the spotlight today. The PB-09 and PB-10 are intended to be used together, with the PB-09 being male, and the PB-10 being female. African ebony wood is used in the manufacture of these footers, presumably for their density and musical properties (ebony is used in many musical instruments for their tone). Ebony wood is of such high density, that it sinks if you put it in water.

The Yamamoto has above average bass, with some useful low frequency extension. It's strength lies in mid-bass and the midrange, where there is a good balance of clarity, sweetness and warmth. Piano notes have realistic timbre with impressive weight, especially on the left-hand notes. Vocal lovers would be very taken by the Yamamoto. High frequency wise, it lacks a bit of extension.

Test Bed

I originally intended to try each footer under  two different components, a relatively light DAC, the Audio-Gd DAC 19 DSP, and my CD Player, the Cary CD-500. Halfway during the test, I realised that the stock footers of the Cary were quite high, and a number of footers were not tall enough. Instead, my Almarro A318B and Calyx Femto DAC were used. I also tried some of these footers under my power supplies and my Conrad Johnson power amp.

As no footer works best in exactly the same location, I experimented with placement. Each footer would be evaluated in isolation over a few days, before the stronger contenders were pit against each other.


Readers hoping that I would crown one of the contenders here as being the best, will be sorely disappointed. None of the footers here performed consistently across all equipment, and weight loads. Some had a preference for lighter equipment, while some only shone under heavy loads.

That being said, it would be impossible to come out from such a test without a few favourites.

The Magic Hexa deserves special mention for best bang for the buck.

For lighter equipment, I especially like the Ceraball and Stillpoints Ultra Mini.

For moderate loads, I like the Stillpoints Ultra SS.

For heavy loads, it is a toss-up between the Franc Audio Ceramic Disc Classic and the Finite Elemente Cerabase, depending on the tonality sought.

Sunday, May 13, 2012

Okki Nokki Record Cleaning Machine

Photos from official website


The Okki Nokki record cleaning machine is probably one of the most affordable vacuum based record cleaning machines on the market. Locally, it costs a shade under S$ 900.

The Okki Nokki has a bi-directional motor (a useful function to brush the grooves of the record in both directions), and comes supplied with a small battle of record cleaning concentrate, and a goat's hair brush.


The Okki Nokki is quite idiot proof to operate. Two switches control the unit. The top switch toggles between clockwise and anti-clockwise rotation. The bottom switch controls the vacuum.

The vacuum motor has a useful automatic shut-off feature in case the reservoir becomes full. A visit to the kitchen sink, pull out the tube behind the unit, and drain the dirty fluid out.

With a bit of practice, you can apply the cleaning fluid, brush the surface over a few revolutions in both directions, and vacuum up the dirty fluid, all in about a minute a side. The vacuum arm is spring loaded and you push it down while engaging the motor switch. When you switch it off, the arm will lift off the record automatically. The arm is lined with replaceable velvet strips to prevent damage to the record surface.

Thankfully, the motor is relatively quiet (as far as vacuum motors go), and you should be able to vacuum your records in the late evenings, without risking a visit from your irate neighbour.

Even during relatively long record cleaning sessions, the unit was never more than warm to the touch.

Although the machine is sturdy and solidly constructed, it also shows signs of being rather rough in appearance and assembly. The metal panels do not line up perfectly, and some dings and dents are visible in certain areas (my machine was brand new !).

Of particular consternation was the fiddly record clamp. The spindle threads continued to flake off metal filings over many record cleaning sessions - a visit with the house vacuum cleaner proved necessary to remove the debris.

Also, no cover is supplied. A suitable acrylic cover is available as an optional extra. You would not want dust all over your platter, so you will need to find some way to keep the dust off.

Operation was flawless though, although there was a tendency for the velvet strips on the record cleaning arm to become saturated and to deposit liquid on to the records as it lifts up after the vacuum motor is switched off.


Prior to the Okki Nokki, I was using a spray-on cleaner that requires a simple wipe off after application, without any brushing. While the spray was somewhat effective, it was expensive, and a chore to use. The Okki Nokki also had much better results.

Anyone with more than a handful of records really needs a good record cleaning machine. Many of my records were picked up from dusty piles yonks ago. I had written off almost all of those records - they sounded dull, lacking in dynamics - just awful.

After a clean, the records were quieter, clearer and more dynamic. Given our tropical weather and humidity, some of the records in question could qualify as fungus production farms. I am eternally grateful to the Hi-Fi Gods that I gave my records a spin in the Okki Nokki before binning them.


Give the Okki Nokki a try if you are looking for a decent budget record cleaning machine. It may not be the last word in finish and aesthetics, but it works well and is effective.

Given how much good vinyl costs nowadays, this is a must have investment if you are even remotely serious about vinyl.

Final recomendation - Okki Nokki ! (Thumbs up in Dutch)

Friday, May 4, 2012

Eastern Electric Minimax Tube DAC Plus

Eastern Electric Minimax Tube DAC Plus

The 4 op-amps in clear view. The two white plastic capacitors are coupling caps for the tube output stage

A closer view. The OEM M2Tech USB board is at the rear of the unit
The subject of this review is the Eastern Electric MiniMax Tube DAC Plus (which I will refer to as the “Plus”), which is an upgraded version of the original Minimax DAC. The original Minimax DAC was based on the Sabre ES9018 DAC chip and was unusual in offering a choice of both a solid state and tube based output stage (using a single 12AU7 tube), and volume control.

In comparison, the Plus loses the volume knob and upgrades its crippled USB input (red book only for the original version!). There are also a number of component changes, including an upgrade to separate power transformers to handle its digital and analog sections, and some fine tuning in the power supply and tube output stage.

Input flexibility remains excellent with a total of 5 inputs, USB, BNC, RCA, Optical and AES / EBU. The USB port (sourced from M2Tech) now supports up to 24/192 kHz sampling rates and is asynchronous.
Output is single-ended only. Why no balanced outputs considering the ease of implementing this out of the ES9018 ? I presume this is because of the single tube stage. Having a tube stage for balanced operation would require a second tube at the very least.

The front panel (like the original version) also offers on-the-fly switching between the tube and solid state output stage, as well as phase inversion. The unit does not remember user settings and will revert to the tube output stage as a default when switched on.

The tube output stage is constantly energised once the unit is switched on, so you can forget about leaving the unit on permanently unless you listen to the solid state output stage, and remove the tube from its socket all together.

Physically smaller than standard component dimensions, the Plus is best described as a slightly shrunk 2/3 scale model. Fit and finish are very high for the price and operation of knobs and buttons always feels solid and reliable.

Thankfully, tube replacement is relatively easy, as the tube is accessible from the rear panel. However, it is a bit fiddly as there is a tube damper / shield to remove first. The tube sockets are very tight and physical space is limited to pry the tube out from. Users are best advised to remove the top cover first before trying to remove the tube - the additional space on top makes this a far easier task.

This unit is well run in having been bought second-hand. The Plus replaced the Calyx 24/192 DAC on my equipment rack. Both units were setup in the same way, fed by a 2011 Mac mini running Pure Music 1.84. The digital signal is then fed via USB to the DAC. For USB cable purposes, I alternated between a L A T USB-2 cable and my regular cable, the Entreq Konstantin (hooked up to the MinimUs ground conditioner)

Sound quality

Initial listening experience with the Plus was disappointing. After a good 20 minute warm up for the tube stage, the Plus was clearly not as resolving as the Calyx, with a slightly vague and hazy presentation. Somehow, the ESS Sabre micro-detail magic was missing. Who let the pixie dust out of my system ?

Switching to the solid state output stage was a wholly different matter. The characteristic ESS Sabre sound was back. Being a dyed-in-the-wool tube person, this was somewhat disappointing. The sand based output was clear, incisive, with both more 3-dimensionability and authority. Arguably, the only advantages offered by the tube output stage was a slightly thicker tonal density, more mid-bass bloom and smoothness.

Most of my listening was eventually done on the solid state output stage with upgraded op-amps, which is covered in greater detail below.

The Plus would be best described as a smooth operator, with a slightly warm and laidback tonal balance. It would never be accused as being bright, but cleverly avoids sounding overly warm and woolly. Consistently even handed throughout the frequency range, the Plus does not overemphasize any part of the frequency specturm.

Bass is tuneful and would be considered as class average in terms of impact and extension. Drums and double bass have suitable impact and depth respectively.

Midrange is smooth and detailed and the human voice is quite engaging. I noticed though that the voicing on the midrange is warmer and sweeter than usual. Listening to Eva Cassidy's album, "Live at the Blues Alley", Eva's characteristic clear and sometimes piercing voice was thicker and sweeter than usual. The usual sibilance problems with her voice also seemed to be greatly reduced.

High frequencies are detailed and extended, with equal emphasis between the leading edge and reverbation from crash cymbals. In comparison, the Calyx has less snap on the leading edge, with greater emphasis on reverbation.

Soundstaging wise, the Plus has a more intimate presentation compared to the Calyx 24/192, with the impression of being seated at least a few rows closer to the performance.

Image sizes are slightly larger compared to the Calyx, but with less definition overall. If you like your voice and instruments to have more body and density, you will like the Plus.

In terms of resolving power, and separation, the Calyx is clearly superior to the Plus. The Calyx keeps its composure under the heaviest of mixes, and has excellent micro detail retrieval, especially at low volumes.

Op-amp tweaking

A quick search on the internet will reveal a fair amount of discussion on op-amp rolling. I tried some quick substitutions just to see the magnitude of improvement offered. The stock I/V op-amps, a pair of dual channel NE5332 op-amps were substituted with a pair of National Seminconductor LME49720 op-amps. The solid state output stage, a pair of single channel NE5334 op-amps were substituted with Burr Brown OPA627BP op-amps as well as National Semiconductor's LME49710.

After about 10 hours of burn-in, some listening tests were done. Significant gains in most areas, including bass authority, clarity and soundstaging were observed. This makes op-amp rolling a no-brainer.

As a matter of taste, the OPA627 had a fuller balance, almost sounding tube like in its bloom and liquiity. The LME49710 had more focus and speed. I preferred the much cheaper LME49710 in my system.

For the ham fisted, it would be best to get a more technically proficient friend to help. For the uninitiated who insist on DIY or death, please observe the following,

1. Dual channel op-amps must be substituted with dual channel  op-amps, and the like for single channel op-amps.

2. Ensure voltage compatibility. The Plus has a dual voltage rail of +/- 15VDC.

3. Observe strict anti-static precautions, op-amps are easily fried.

4. Be very careful when removing or inserting op-amps, the legs can be quite fragile. Invest in an op-amp puller.

Tube tweaking and rolling

Any hope for the tube output stage ? Users are advised to try removing the tube shield. I prefer the tube stage without the shield – the sound is noticeable clearer and has more “air”. I generally do not like tube damping of any form, as I find that it can easily make the sound too dark and dead.

The stock 12AU7 tube supplied is brand labeled as “Eastern Electric”. Internal construction looks very similar to Shuguang, and is presumably OEM sourced from them.

I tried substituting the stock tube with a National 12AU7 black plate (likely to be a relabeled RCA). This was much better than the stock tube, but at the end of the day, I still preferred the solid state output stage.
If you prefer the solid state output stage, the Plus sounds better with the tube removed totally - presumably this eases demands on the power supply.

Phase Inversion 

Although some discs sounded better with phase inversion, I left the button alone. It became a bit of a chore having to remember which discs sounded better with inversion. Nevertheless, this may be a useful feature to some.


Locally, the Calyx is almost double the price of the Plus. However, the Plus is an absolute bargain in context of its asking price.

In order not to be misconstrued as a lack of affection for the Plus, I personally feel that listeners on a tight budget should plump for the Plus. So should listeners that have a variety of sources, or would be listening primarily through the co-axial or optical input. The Calyx shines best through its USB input

The ability to tweak the unit through op-amp and tube rolling is to me, one of the strongest points of the Plus. Such tweaking is helpful to fine tune the unit to suit the end result that the user is trying to achieve.

The Plus is a competent performer at a competitive price. Well specified, and offering a choice of both solid state and tube output stages, it is likely to appeal to the masses, although I ultimately preferred the solid state output stage.

On the downside, the Plus is no giant slayer nor class leader in the ESS 9018 product class. The Calyx 24/192 ultimately has its edge over the Plus in terms of confidence, resolution and natural effortlessness.