Thursday, January 6, 2022

Audiophile DC Power Supplies Supertest


In a simple world, switched-mode power supplies should end up in the bin. Linear power supplies rule because that is what everyone says. Let's have a look at whether there is any wisdom in conventional audiophile thinking?

The power supplies on test will be divided into two groups. The first group will be used to power  a Melco N100 Digital Music Library, which accepts a 12V power supply. The second group will be used to power a Weiss INT204 USB/SPDIF bridge that accepts a 6-9V power supply. 

Identical power cords will be used in all cases - an Oyaide Black Mamba. The power supplies will also be switched on one hour before any critical listening is done. Three tracks were played, To whom I give my heart by 2V1G, Colleen's dream by Pat Coil, and Chitlins Con Carne by Kenny Burrell.

12V Power Supplies 

Asian Power Devices DA-48T12 - FOC

This is the laptop brick power supply that is bundled with the Melco N100. It is rated for 4A of current. Unlike all of the other power supplies on test here, the AC inlet is a figure of eight type instead of an IEC inlet. A suitable converter was used to ensure that the same power cord could be used here. This turned out to be an important factor. Using an aftermarket figure of eight power cord (a more modest model compared to the Oyaide Black Mamba) killed the sonics of the Asian Power Devices brick. 

The sonics from the stock power supply was passable at their best. Bass lines while smooth and rounded, lacked depth and power. Vocals while warm and pleasant, were also lacking in clarity and definition. The two vocalists in the 2V1G track as an example, could not be clearly distinguished in the soundstage. The better power supplies in comparison clearly placed one singer in the center, and the other, a few feet away on the left. High frequencies were also lacking in crispness, extension and were a bit dull sounding.

Jay's Audio LPS25VA - USD 168

This is a super-regulated design derived from Walt Jung's super-regulator circuit. High-quality parts are used like a 25VA Talema mains transformer, Phillips BC reservoir caps, and Panasonic FC decoupling caps. This is a surprise given the modest price tag of the LPS25VA.

A front LED panel shows the output voltage, and a trimmer pot on the rear permits fine adjustments to the output voltage.

Somehow this power supply failed to float my boat. There was nothing particularly offensive about the sonics, but nothing to write home about either. While this is a more "quiet" sounding power supply compared to the Asian Power Devices and Meanwell bricks, there is a lack of attack and extension on both the low and high frequencies.   

Kingrex PSU Mk II - USD 419

An oldie but goodie. The Kingrex used to be a popular recommendation, but newer products on the market are more sophisticated from a technical point of view. Nevertheless, this model is still worthy of consideration. Featuring a 48VA toroidal transformer and a massive power supply, the Kingrex can be picked up at an affordable price on the pre-owned market.

Looking under the hood, this looks like a simple electronic design, with a three-pin regulator, and a variable resistor to set the output voltage.

I used my personally constructed DC lead for this, a Neotech PCOCC copper cable. The original lead was long lost in my hi-fi jungle.

Listening to the Kingrex brought back good memories. A competent performer in all departments, the Kingrex has good bass, and sparkling extended highs. Cymbals in particular, are reproduced with a crisp strike and decay. The midrange is warm and smooth, but some fine detail is lost. While the bass has weight, it lacked the tightness and slam managed by the best of the power supplies here. 

Pat Coil's piano playing and the saxophonist on Chitlins Con Carne lacked some impact and attack as an example.      

Kingrex SLAP - USD 450

Creative naming from Kingrex's marketing department! The SLAP is a Sealed Lead-Acid Battery Power supply unit. Weighing a whopping 7 kg, this brick is fuss-free with a built-in battery management circuit. Some people think that battery power is the only way to be truly isolated from the nasties on the electricity grid.

Meanwell GST60A12-P1J - USD 18

Meanwell is one of the big names in industrial and commercial power supplies. The model on test here is a 12V/5A brick switched-mode power supply. The Meanwell provided massive bang-for-the-buck. Users of the Melco that are on a tight budget could consider this as a no-brainer upgrade. You get better bass authority and control, clearer and more distinct vocals, and more extended highs. The Meanwell will not pose a threat to any of the better power supplies here, but you can't argue with its value proposition. 

Paul Hynes SR4-12 - GBP 342

The SR4 comes in two models, the SR4-12 which has user-selectable voltage settings from 5 to 12V, and the SR4-19 which has voltage settings from 9-19V.

The SR4 utilises a balanced mains isolation transformer and a discrete regulator circuit. Current output is 2A continuous and 20A for transients. The SR4-12 was tested with a silver wire DC lead that may be purchased from Paul Hynes as an option. 

I enjoyed listening to the SR4-12, although I felt that the sonics were shaped by the silver wire DC lead to a large extent. Quiet and confident-sounding, the Paul Hynes has lovely silky highs that are extended, yet delicate and refined. Authority and control are behind that of the Plixir Elite, and busy mixes did get a little bit messy at times.

If your musical diet consists of small-scale classical and jazz pieces, or female vocals, the SR4-12 will really suit you. 

Plixir Elite BDC 6A - S$ 1,059.30

Proudly made in Singapore, the Elite BDC features a balanced power transformer and three-stage noise regulation. This is the usual power supply used with the Melco. The Plixir has a firm and neutral sound, with good control over transients. This is a highly resolving power supply and a reference standard for me.

Sean Jacobs DC4 - from GBP 5,400 (no typo!)

The DC4 is the power supply that people talk about in hushed tones amongst those in the know. Entry to this hallowed circle requires very deep pockets and one additional rack - this power supply is as big as an amplifier.

The model I had on hand is able of supplying three 12V supplies, so that brings down the cost of ownership somewhat. Current is limited to 2A per rail due to "CX" module fitted in the regulator module, although this can be bypassed for higher current delivery. The stiff asking price buys you premium parts such as a custom-made toroidal transformer, Neotech OCC internal wiring, Vishay Z-foil naked resistors and Audionote Kaisei capacitors in critical sections.

Using a silver wire DC cable from Sean Jacobs, this power supply blew away most of the competition. While this is not the most forceful, incisive or dynamic sounding power supply, the DC4 was able to serve up extremely high amounts of detail while sounding natural and textured. The DC4 nailed timing, sounding just right. It has a level of refinement and quietness that exceeds even the Plixir Elite. However the Plixir has better slam and bass punch, and dishes up a very close level of performance for a lot less money. Like most statement-fi products, whether the price tag is justified depends on personal opinion.

Sbooster BOTW Power & Precision Eco - GBP 260

The Sbooster supports up to 3A of current and has selectable voltage between 12-13.2V. The Sbooster utilises a dual-stage mains filter and Earth line choke. The unit on test is the original model, which has since been replaced by a MkII version.

This is definitely a good step-up from stock power supplies, with a very quiet background and an increase in resolution and control. Bass has less authority than the Plixir and there is subtle grain and splash in vocals and transients. The midrange is also forward, which results in soundstage that is projected forward. 

SOtM sPS-500 - USD 500

Unlike its competitors, the sPS-500 is a switched-mode power supply. It has user-selectable voltages ranging from 7-19V and is capable of supplying up to 5A of current at 12V and 3.3A at 19V. The DC output socket uses a Hirose connector that will test your soldering skills if you intend to construct your own DC cable. As the supplied cable is annoyingly short, you will likely need to order an aftermarket cable.

This sPS-500 has a very precise presentation, with very focused imaging and soundstaging. Bass is nimble, tight and deep, but drier compared to most of the other power supplies on test there. Subjectively, music sounds brighter with a noticeably uplift in treble energy and "air". Vocals also have a subtle degree of projection. Music has a very crisp presentation to it, although vocals have more sibilance compared to the rest of the power supplies. 

Uptone Audio JS-2 - USD 925

The JS-2 has two independent and separately adjustable regulated outputs ranging from 5-12VDC with 5A current capability. Uptone took the unusual path of using a choke filtered power supply, an approach that is more commonly used in tube equipment and is less popular due to the increase in weight and cost. You get two power supplies for the price, which makes it easier to swallow.

6-9V Power Supplies

Meanwell GS25A07 - FOC

This is the stock power supply that is bundled with the Uptone Audio Ultracap. The model is discontinued, but the successor retails for around USD20. Voltage is 7.5V and the current rating is 2.93A.   

Uptone Audio Ultracap LPS-1 - USD 395

Based on super or ultra-capacitors, the LPS-1 was a ground-breaking product at its time. Voltage is selectable between 3.3, 5 and 7V with 1A current rating. Charging and bank-switching is handled by a microprocessor.

Uptone Audio Ultracap LPS-1.2 - USD 435

The successor to the LPS-1 covers voltages between 5 and 12V. Current rating at all voltages is 1.1A. New output voltage regulators are used in parallel to reduce noise as well as output impedance. 

To be continued ... 


Wednesday, January 5, 2022

WFH Special #1 - Creative SXFI Gamer USB-C Gaming Headset


The SXFI Gamer is a wired USB-C gaming headset with Super X-Fi technology and a flexible goose neck microphone (Creative Technology refers to this as "CommanderMic"). 

I am not suggesting that you play computer games during office hours while on your work-from-home stints. Instead, use your SXFI Gamer for conference calls, listening to music, and gaming sessions. You won't get the evil eye from your spouse too when justifying your purchase.

The recommended retail price is very reasonably priced at S$ 179.


Super X-Fi  is Creative's proprietary technology that seeks to create a life-like soundstage that is akin to the music experience of listening to speakers. Regular headphone users will know that the soundstage is trapped in your head, which greatly diminishes the realism of the listening experience. 

To use Super X-Fi, you need to download the SXFI App on your phone, create an account and start the process of head and ear mapping. This involves using your phone camera to take pictures of your face and ears. 

The personalised settings are then downloaded into a SXFI certified headphone, like the SXFI Gamer.

The package includes the headphone set, the detachable CommanderMic, and both a USB C and 3.5 mm audio cable. A USB-C to USB adapter is thoughtfully provided in case your computer only has normal USB ports.

The 3.5mm audio cable looks like any stock cable, while the USB C cable is Kevlar jacketed which should provide long and reliable use. The USB cable is unfortunately very sensitive to microphonics and friction between the cable and your clothes will be picked up and annoyingly amplified.  

The headset comes with large and heavily padded over-ear pads which are mounted in a plastic frame that allows a small amount of swivel. Combined with the low-pressure headband, the SXFI Gamer is very comfortable to wear for extended periods of time. Noise isolation is also decent, with both little noise making it through, or being leaked out. The headband also has a numbered scale to make adjustments both easy and repeatable - something I wished that other manufacturers would do. Both headphone cups are equipped with an RGB ring. This is tastefully done, and you end up looking like a serious gamer rather than out-of-control Christmas tree lights.

Downloading the SXFI Control program on either your PC or Mac will allow you to adjust the EQ on your headphone, as well as customise the RGB rings on your headphone. You can also adjust between 2 channel mode and 5.1 or 7.1 modes, and other settings like the microphone and headset volume.

A variety of controls are placed on the left side of the headphone - a mic mute button, a volume control wheel, and buttons to toggle Super X-Fi and the RGB light mode (on, off, or a cycle mode).

The CommanderMic is equipped with active noise cancellation to suppress ambient noise. A red LED is placed at the microphone inlet so positioning is easy. The LED flashes when the microphone is muted, which is a nice touch.

I used the SXFI Gamer via USB on both a Windows 10 and macOS Catalina computer without any issues. I also did some testing via the 3.5mm jack on a variety of mobile phones and DAPs. 

Sound Quality  

Tonally, these headphones are close to neutral with good levels of detail. The 50mm drivers impart a solid and hefty feel to bass lines. However, the SXFI Gamer avoids the thick and heavy handed approach, so you will not get overblown or exaggerated bass. Bass is tight and tuneful, and powerful when the source material dictates it. If you like a bass-heavy presentation, you can always fix that through the EQ function.

Vocals are reproduced clearly and with minimal amount of grain. High frequencies have sparkle and extension, and cymbals have a crisp and clear response. There is a hint of splash and confusion during heavy mixes, but this is to be expected given the modest price of the SXFI Gamer. Sonics wise, these headphones perform way above the competition in the same price bracket.

Depressing the SXFI button toggles between the normal, Super X-Fi and Battle Mode. I found the Super X-Fi mode to work best on 5.1 and 7.1 material. At its best, this imparted a spacious and more speaker-like experience. However on 2 channel material, the effect is somewhat unnatural and hollow. Similarly, Battle Mode did its job on first-person shooters by altering the frequency curve to accentuate footsteps and suppressing the rest of the audio-band. While you can hear your enemies better, this came at the expense of an unnatural tone that made the experience less immersive and realistic. 

The surprise star of the show is the CommanderMic. The microphone is very clear and the software does a decent job of suppressing ambient noise. However, the microphone is highly directional and has to be pointed directly at your mouth for best results. I often preferred using these headphones for conference calls over my professional headsets from big-name manufacturers. 

The SXFI Gamer sounds almost identical using the 3.5mm cable, with results varying only slightly depending on the equipment used. These headphones are easy to drive and sound comfortable powered through a mobile phone jack. However, you will lose a lot of functionality as none of the buttons nor sound modes will work. Nevertheless this is a good option so that you can take the SXFI Gamer on a business trip and use them on the road or airplane with your mobile phone or DAP.


Equally comfortable doing multiple duties as a gaming or office headset, or music listening for the audiophile on a budget, the SXFI Gamer offers outstanding value at its recommended retail price of S$ 179. 

At the time of writing, they are being offered at a discounted price of S$89 which makes this an absolute no brainer - Best Buy. 

Creative SXFI Gamer USB-C Gaming Headset


Audio Processing
Super X-Fi
USB, 3.5 mm Stereo Input

With Mic 349g (12.31 oz), Without Mic 336g (11.85 oz)
Frequency Response
20–20,000 Hz
Frequency Response: 100–16,000 Hz
Sensitivity: - 42 dBV / Pa

Price : S$ 179

Sunday, October 31, 2021

Devialet Expert 140 Pro Amplifier


Mei impatiently twirled the ends of her long hair as she waited for Joe outside The Adelphi - Mecca of all audiophiles in Singapore. Minutes later, Joe appeared in a huff and drenched in perspiration - the humid tropical weather was especially unkind to office workers in their impractical attire.

"Took a leisurely walk here Joe ?" Mei commented sarcastically before defusing the sharp edge of her words with the sweetest smile ever.

Joe ignored her remark and quietly opened the door, heading straight for the shop that carried Devialet products. Mei had tasked him to find a suitable stereo system for her and he thought this fit the bill even though it was too much of a compromise by his exacting audiophile standards.

Mei and Joe were welcomed into the shop (Joe was a regular customer there) and after some refreshments, the salesperson ran them through the features of the Devialet Expert Pro amplifier. Mei sat down on the sofa with Joe standing behind her. She scrolled through the iPad lying on the sofa and within a minute, her favourite tunes were playing sweetly through the speakers in front of her. She twirled the knob of the remote control a few times and nodded approvingly. After a few tracks, she got up and walked over to the Devialet amplifier that was sitting on the top shelf of the component rack. She brushed her long slender fingers on the beautifully chromed chassis. It looked like a futuristic slab of metal, with just a single small circular window breaking the uniformity of the top panel.

"This is a very beautiful piece of art. Will you help me set it up ?" Mei smiled at the salesperson with her dimples barely showing.  

"Ah! Of course Miss. We will set up the whole system for you. If you have an existing music library your boyfriend can help you connect it - it's really easy." The salesperson could smell the scent of a pending sale and the soon-to-be-earned commission was already warming the cockles of his heart.

"Boyfriend? Please!" Mei dismissively replied while rolling her eyes disapprovingly. Joe blushed at both the salesperson's words and the sting of Mei's response.

"It's a digital amp and you are paying a premium for a lifestyle product!" Joe protested at Mei's impulsive decision. Mei ignored Joe and continued to stroke the Devialet lovingly.

Thankfully, the salesperson managed to close the deal and the Devialet was delivered promptly to Mei's home with other components to make up her minimal and very tasteful music system.


Mei and Joe are fictional characters, but there are many music lovers like Mei. They want a beautiful and good-sounding amplifier that can fit nicely into a modern home. Too many audio components look like something from a mad scientist's laboratory, or the control panel of a nuclear reactor. 

My very first experience with Devialet dates back many years ago when the D-Premier was first launched. A fellow audiophile was very eager for me to listen to it, and he turned up at my doorstep with a large flat box under one arm (don't try this with conventional amplifiers!). It was an impressive experience, with a laidback and slightly warm sound that was more than powerful enough to power my speakers then - a pair of Focal Diablo Utopia bookshelf speakers. Positive impressions aside, there were some glaring omissions in my opinion, the prime ones being unstable wi-fi streaming and a lack of a USB port. 

Was the D-Premier equal to my stack of components which were of equivalent value? Like a directionless corporate meeting, we respectfully agreed to disagree. He preferred the D-Premier, while I preferred my clumsy stack of components. He mischievously reminded me that the D-Premier was cheaper by a significant margin once I took into account the many footers, cables, power cords and rack space involved with my traditional stack.

The D-Premier cost close to S$ 20,000 when it was first released in Singapore. Thankfully, Devialet has worked hard over the years and the entry-level model (the subject of this review), the Expert 140 Pro is much more affordable.


The Expert 140 Pro retains the sleek lines of the D-Premier. It is sexy enough to elicit envious glances from the most jaded audiophile. It has a more than passing resemblance to a high-end bathroom scale, and can even be mounted on the wall if you so desire.

A small port window shows various information including volume, source, and the status of SAM, and network connections. A single button powers up and shuts down the unit, while a sleek remote control controls commonly used functions (or as customised by the user).

Beauty here is not merely skin-deep. The Expert 140 Pro packs impressive amounts of technology and integration. Apart from being a powerful integrated amplifier, it also contains a DAC, phono stage (both MM and MC) and streamer. 

The most controversial design point is that everything is handled in the digital domain. In the case of the phono stage, or analog input, the signal is converted to digital using a high quality A/D converter. Listening to your records after it has been digitised ? Sacre Bleu !  An optimist would of course focus on the benefits of having the signal in the digital domain, including the ability to process the signal using powerful DSP. Devialet is able to do this for both the partnering record cartridges (RAM) and speakers (SAM). The digital heavy lifting is carried out using a Quad-core 1 GHz CPU and 2 X SHARC 400 MHz DSP units.

Despite the compact form factor, the Expert 140 Pro packs a powerful punch. Power output is 140 W per channel into 6 ohms. Amplification is achieved with a hybrid design that combines a Class A amplifier (providing voltage amplification) with Class D modules (providing current). In a way, this concept is similar to the current-dumping design launched by Quad in 1975 which combined a Class A amplifier with "current-dumping" transistors to supply the necessary current. Class A designs are required to dissipate tremendous amounts of heat and a design that could deliver power equivalent to the Devialet would be massive and put out enough heat to warm a small room! 


Record Adaptive Matching (RAM) is available in the Expert 220 Pro upwards and the Expert 140 Pro only allows a choice between MM/MC and adjustment of sensitivity. RAM allows the user to choose more than 256 combinations of resistance and capacitance, as well as a choice of equalisation curve. 

Speaker Adaptive Matching (SAM) is a complex compensation model that attempts to correct sub-optimal speaker behaviour. Devialet measures the speaker in question to create a map of more than 60 parameters. The model is derived from measurement of the crossover network, speaker driver displacement, deformation, maximum displacement, speed and acceleration. Speaker models are continuously added to the SAM database, and the current database stands at more than 900 models. Conveniently, both my Vivid Giya G4 and Tannoy Kensington GR speakers are listed in the database. 

A worthy mention is that SAM allows extension of your low-frequency response, with sensible protection built-in to prevent you from blowing up your speakers. It can be switched in and out on the fly using the remote control. By configuring your remote, it is possible to adjust the level of SAM correction from 0 % to 100 %.


An online configurator allows you to set up your Devialet according to your preferences. You can configure your inputs to be either digital or analog (either line-level or phono), and apply SAM, and phono settings too. 

This is just scratching the surface of what the configurator allows you to do. You can also (this is just a shortlist of features available) customise your remote control buttons, adjust the sampling rate of the ADC for analog inputs, set individual sensitivity levels, and adjust the maximum power output allowable from the unit.  

The configuration file is then saved onto an SD card which is inserted into a slot at the back of the amplifier. You could create multiple configuration files to be saved on different SD cards should you wish to show off your amplifier in another person's system. 

Operation and Ease of Use

Getting the Expert 140 Pro up and running was quite easy, save for the scare I got from the non-responsive remote. It turned out that the installed batteries were dead even though my unit was brand new. 

The compact dimensions do require you to use a power cord with a slim IEC and banana plug terminated speaker cables. In an all-time first, an entry level Audioquest power cord is supplied in the box. In case you insist on using your massively sized power cords, a removable rear plate allows you to do this, losing a bit of stylishness in the process.

I never got the Devialet to stream from a DLNA server source, and neither did I install Devialet Air (the companion streaming software) as this runs on a personal computer (which I do not use in my main system). Instead, I used the Devialet as a Roon endpoint where it worked seamlessly. You can also use Airplay and Spotify Connect if you want to.

I did have the odd occasion where the Devialet failed to detect the SD card upon start-up. However, powering the unit down and re-inserting the SD card solved this. I found it odd that Devialet used such a primitive method of configuring the unit when everything else about the unit is technologically light-years ahead of the competition. The configuration file is a text file that can actually be viewed and edited, which seems dated. It would have been nice to be able to configure the Devialet using an app instead. Instead, the free app works as a substitute for the remote control. 

My remote also had an issue with batteries, eating up fresh alkaline batteries every 2-3 months on average. No wonder, the factory-supplied batteries were flat on arrival! I've read of other users having similar issues, and this apparently can be fixed by the factory.  

Sound Quality

The Devialet appeals as a lifestyle product and brings with it the misconceptions of an overpriced and inferior product. Actual use (I've had my set for more than two years) proves that this is a highly versatile product that is a viable and attractive alternative to a stack of components with spaghetti cabling everywhere! I have brought the Devialet along to listening sessions in other setups where they have always acquitted themselves, even against very expensive equipment.

The Devialet does have a subtly sweet and rich tone that is pleasant and inviting. The Class D detractors would have to leave in disappointment at this juncture. The midrange in particular is sweet, smooth and laidback. The bass quality is good, with power and a full textured midbass. In fact, you could argue that the Devialet takes the polite path rather than a sharp, or hyper analytical route. The high frequencies are also cleanly reproduced, without any noticeable evidence of roll-off or anomalies from the low-pass filter required for Class D designs to filter out ultra-sonic noise.

I would rate the Devialet's performance as reasonable for the price. However, enabling SAM lifts it up significantly. Apart from the very obvious boost in bass extension and power, there is an increase in focus and coherency that makes it very hard to revert back to SAM-less listening. Play it again Sam!  


The Devialet is a superb all-in-one that demonstrates that convenience need not come at the expense of sound quality. It's a pity that traditionally-minded audiophiles may not give the Devialet due consideration. 

With shrinking living spaces in Asia, this is the perfect product that ticks all the boxes :- looks, convenience, quality and price. Some may disagree that the Devialet is an affordable product, but I am convinced based on the many boxes it replaces, and the outstanding sound quality it delivers - Highly Recommended.    


Mei sat gracefully on her sofa, listening to music from her new sound system. Joe had managed to convince her to install the Expert 140 Pro amplifier on top of her cantilevered TV rack. Discrete cabling ran to two very slim floorstanding speakers. The system was a perfect foil to Mei's character - graceful and elegant.  

Her music collection had been ripped and stored on a dedicated Intel NUC PC that functioned as a Roon server. Joe had also subscribed to Tidal in case Mei wanted to explore new music just like she did when she came over to his home.  

Standing up, Mei surveyed the very neat job that Joe had done in arranging everything. Her long flowing white dress showed off her slim waist and she glowed like an angel. Joe's heart skipped a beat and he bit his lower lip hard.

Devialet Expert Pro 140 Amplifier

Price : S$ 8,990