Understanding Valve Amplifiers, by Charl Du Plessis

Model A Setup Instructions

Plessis Isolation Spikes

The Plessis spikes ($15) can be used under just about any audio equipment you want to benefit from their isolation action. The improvement in sound from players, amplifiers and speakers have been noted by audiophiles for many years, but getting a high quality metal spike of this type at the right price has been a problem.

They are stainless steel, 32mm diameter, with gold plating. If you require it, each can have a protective disc to go underneath and prevent damage to floors or cabinet bench tops, at an additional $10 each for the matching discs. The matching discs can also be bought separately to go with your existing spikes, as the case may be.

Typically you can use three of these under each piece of equipment, and they are then self-levelling, but there's no problem using four if you prefer. Isolation spikes are known for their uncanny ability to reduce distortion which it is surmised comes about through mechanical and even electrically generated vibrations in players and amplifiers. Speakers are full of vibrations, of course, and dissipation of these through a good set of spikes will help clarify the output at that stage of the process as well.

Letter From A Customer ...

"While I'm not a professional audiophile reviewer (so please bear with me), I felt compelled to let you know just how enjoyable (amazingly good) your Model A integrated tube amp is, with the advantage of being quite striking in appearance. Over the years I have had many tube based amps, including integrated, pre's and a hybrid power amp.

To date, this is by far the best amp I have had in my system since getting hooked on fine audio over 20 years ago.

What impressed me during the audition of the Model A was just how musical and neutral the amp was. During the audition the Model A was compared against numerous other tube integrated amps of similar power, from many parts of the world, including China and the USA. The Model A was by far a step above some very well respected amps.

Another aspect that really surprised me was how much punch the amp has while only being rated at 40W/ch (Ultralinear) and 20W/ch (Triode mode). For the first time I started to appreciate that even a supposedly low powered amp can sound far more powerful when spec'd and built to high standards. It amazes me that at moderate volume levels in either mode, the amp seems to pack more punch than my trusted 300W hybrid power amp.

The inclusion of a high quality meter and toggle levers which allows you at any time to check the bias of the EL 34 tubes is just brilliant. No need for additional amp-meter or hard-to-get-at test points. All the owner requires is a flat screwdriver.As mentioned in the owner's manual this is a unique feature, which to me places this amp well above many others in the mid to high-end category, at numerous price points.

The other brilliant yet simple inclusion is the elapsed time meter. This feature allows the owner to not only monitor tube performance against time, but if so desired the owner can maintain a log of different tubes versus life span, how cool is that!

Now that I have been listening to the amp for over 350 hours I'm still amazed at how good this amp is. Whether its vinyl or CD playing as the source, the sound stage, imaging, the realism of studio or live recordings just blows me away, or more accurately prevents me from sitting still! Being such a neutral and accurate amp, it has also identified some not so good recordings that weren't highlighted as accurately with previous amps.

What I have noticed is how frequently I'm again listening to my hifi system, literally daily, whereas prior to the Model A it was maybe once per week. Listening to it for hours on end is also not tiring, another great achievement.

I can validate for you that your design intent has been met, perhaps even exceeded, and all for under $5k, and it's origins are local, how good is that! I would hate to think what this amp would cost if it originated from the USA or the UK for example.

I do however have two minor negatives and appreciate it is purely a personal thing. Firstly the inclusion of an "exclusive" Plessis Audio screwdriver would have been neat. Secondly, it would have been even better to see all tubes from the front of the amp, I do appreciate this is due to the design layout and not an oversight. Bloody well done mate, fair dinkum! Sincerely, Peter Austen"

Plessis Audio Model A Integrated Valve Amplifier - Review

From Audio/Video Lifestyle Magazine - by Nic Tatham

Certain parts of asia have long held valve-based amplification in high regard. In countries such as Japan, Korea, Singapore and Taiwan, your real music and hi-fi enthusiast just doesn't entertain the thought of any other type of amplifier. Usually, there's a pair of horn-loaded speakers on the end and exotic turntables or CD players front such "audiophile" systems.

But, mention valve hi-fi products these days and it's now China which is fast adopting them as its own, both in terms of manufacturing and enjoying. The musical benefits that valves have long been noted for. It's natural to expect a sub-$100 DVD player to be made in China, but a $10,000 CD player or $5,000 amplifier? Well, in the People's Republic high-end hi-fi is booming.

Two such products are reviewed in this issue - Shanling's limited edition CD-T300 CD player and this, the Plessis Model A integrated valve amp. Although built in China, this amplifier has strong Aussie connections. Charl Du Plessis is the man responsible for this particular amplifier, plus another more affordable transistor-based model, the Plessis Audio S1. But it's this, the Model A that has been whetting music lovers' appetites.

Some background as to how Plessis Audio came about will give a better understanding about how the company and its products came into being. Charl came from South Africa to Australia back in 1996, after many years working in the hi-fi industry, specifically marketing a wide range of products such as NAD, Mission, Wharfedale, Krell, Acoustic Research and others. His work in cable and radio design led him to and his colleagues ("the team") to China. The Model A valve amp and S1 transistor-based amplifier have been partially designed in Australia, while the rest of the research and development took place in China. He and the team listened to, tested and evaluated some 40 different amplifier designs from around the world, before determining its own amplifier designs, a process that took over two years to complete.

The fruits of these labours have finally been borne and the Model A is the one people are getting most excited about. It's an integrated valve amplifier designed to cater for the mid to high end of the market but at $4999 the price certainly isn't silly money, as you can easily pay for some exotic valve amps. What's more, the model A was designed to be practical as well - all too often you can use only the most efficient of loudspeakers with low-powered valve amps, but this one suffers no such compatibility issues. It has two output ratings, and maximum power output is 40 watts per channel in what's called Ultra Linear mode while this output is halved to more like valve power in Triode mode. The difference between the two, apart from power output, is also in distortion (which doubles), but with the right speakers, the reward lies in just how realistic and tepid valves can make certain music sound. More on this later.

The valve complement is eight all up; two per channel matched Russian-made EL34s provide the main output, and situated between twin output transformers stand smaller input and inverter valves. This valve layout design is a reverse of the norm, and visually, from the front at least, things are dominated by a large power transformer, MA meter and twin knobs. It's not the most blatant looking amp, but I really like the unusual styling. Build quality is what you'd describe as military - very solid and no-nonsense. The amp's chassis is machine brushed aluminium and combined with those hefty transformers, the Model A weighs in at 20Kg.

A couple of aspects of using valves is that they need regular bias calibration, plus eventual replacement. Valves have a finite usable life span, but it's tough to evaluate just how long that is, until the valve finally dies. However, a nice touch on this amplifier is a four digit electronic timer displaying the time of use in hours of the power amplifier valves. Calibrating the bias is normally a professional (and costly) job, but in keeping the Model A as practical as possible it can easily be done at home. The MA meter and four toggle switches display the bias for each valve, which can be easily adjusted via a toggle in front of each.

The sample I received had already 160 hours under its belt, so it was well and truly run in. My speaker choice was simple for reviewing the Model A. Given its two mode operationand the very high sensitivity of my Ambience 1600S Hybrid ribbons, they made perfect partnering sense. I stuck with the CD-T300 as the main source as well. Turning the Model A on, you have to wait for about 80 seconds before it clicks on and the valves are glowing sufficiently for operation. I started out listening in Ultra Linear mode and the full 40 watts per channel, which is quite substantial and sounds it. With a 96dB sensitivity it didn't take much persuasion to coax the ambience into life. Of all the amplifiers I've used with these speakers, to my ears a decent valve amp brings out their best. It's perfectly feasible to use amplification10 times the price of the model A with these speakers and they'll reveal all and to its credit the Model A punched nicely above its weight, both in terms of real power output and price. Had this amplifier been manufactured elsewhere it would no doubt cost significantly more.

After a few minutes and the amplifier had reached optimum warmth, and its glowing potential is soon apparent. All the hallmarks of really good valve sound are here - finesse with a sense of naturalness, transparency and detail combined with excellent speed and dynamics. The latter is something the Model A does particularly well and there's never a hint of sluggishnessor sounding overly warm, especially in Ultra Linear mode.

And if you live on a diet of vocals then this is the amplifier for you. Switching to triode mode and just 20 watts per channel certainly didn't faze either the amplifier or speakers, but it did bring out more character and midrange expression from the 1600's long ribbons. Talk about lifelike, I had to convince myself that P.J. Harvey wasn't standing a few feet in front of me. Whether it's the velvet tones of AlisonGoldfrapp or the yell of Ms. Harvey, both their vocal styles are reproduced with character and expression that is tremendously realistic.

Rock? No problem either, although switching back to Ultra Linear mode and the extra watts don't go amiss if you want to push the loudspeakers that bit harder. People's normal expectation of a valve amp is a nice warm sound, but not all that dynamic or able to play loud. The Model A's 40watts per channel go a long way and I was able to achieve fairly substantial volume levels without any hint of strain or breaking up. It also sounds fast and potent too, which is just the ticket if you fancy letting your hair down a bit.

I test every bit of hi-fi with dance and rock music and let me tell you the Model A is no slouch. For this I tried my KEF Q7s on the end of the Model A, as they are a great party speaker and they too revelled in Ultra Linear mode. Switching to Triode the amplifier still coped fine, but not to the same degree as with the highly efficient Ambience 1600s.

If you're after an amplifier that's a bit different, but love what a well designed valve amp can do, then this Model A from Plessis Audio is worth tracking down and having a listen. It's been designed to overcome many of the shortfalls associated with valve output and maintenance, as well as give outstanding performance for the money. I believe it does just that.

Nic Tatham

Plessis Model A Wins Best Amplifier 2006

The Audio/Video Lifestyle magazine Award for Best HiFi Amplifier, 2006, was been won by the Plessis Model A! This is, of course, against a field of dozens of other newly released models during the past year. It is proof that Plessis is on to something good, and that any Plessis product has to be taken very seriously. Charl is nothing if not a hifi enthusiast, but at the same time he is determined to offer great value for money. See below for more details of the amplifiers.

The Plessis Story

Charl Du Plessis grew up in South Africa, although, as you would guess, his family has its roots in France. After finishing uni and a short stint in National Service in the Army, Charl went on to be involved for a number of years in the HiFi industry there, mainly in wholesale distribution. He has an abiding love for good analogue stereo music, and is the proud owner of a much modified Linn Sondek turntable.

Since coming to Australia in 1996 he has continued his interest in HiFi to the point now of releasing his own special products. This short intro gives you an overview of the amplifiers and also details of where to see and hear them, if you are lucky enough to have a dealer nearby.

The amplifier designs have grown from Charl's knowledge of what makes a quality product - he has a keen interest in the components that go into them - and his excellent relationship with the principal manufacturer. Together they have done extensive research into the factors which deliver particular complexions and accuracy of sound. This assists in ensuring that the end result will be a most satisfying one by attending to every detail. Plessis Audio products are at once traditional in style and innovative in what they offer at the exceptionally good price.

The S1 is a compact solid state integrated amplifier, designed with the objective of superlative sound for the lowest possible price. It is rated at 80w into 8 ohms, 130w into 4 ohms, and has four line level inputs. Capable of driving a wide range of speakers, it gives a full and satisfying soundstage, and is on the warm side rather than the thin and incisive side. Details are well rendered, and dynamics are excellent from such an affordable amplifier - in spite of its compact size as well. All the components are selected for quality, right down to the heavy duty binding posts for the loudspeaker cables.

The flagship Model A is a valve amplifier for the middle to high end market - again with superb sound as the principal objective, but also an important commitment to making the ownership of a valve amplifier more user friendly. It has unique owner-adjustable bias and usage logging features which set it apart from most amplifiers. This has many benefits. The sound is optimised if all valves run at the same bias, and it is very easy to do this as often as you want to. Additionally, there is a reliability dividend in ensuring that no valve is running too "hot" and likely to burn out prematurely. Most valve amps have no visible indication of this, and valve failure can result. Delivering 40w/channel in Ultra Linear mode, or an impressive 20w in Triode mode, this is an amplifier to satisfy the most discerning ears. The output valves used are EL34, and not expensive to replace.

There are rumours of a loudspeaker to follow, which would be a very nice complementary product.

Dealer Details

Len Wallis Audio: 64 Burns Bay Road, Lane Cove NSW 2066. 02 9427 6755

Bill McLean's Team: Cnr. Minto Rd./The Entrance Rd., Long Jetty NSW 2261 02 4333 3545

Brad Serhan - contact via website here.

Livingstone Audio: 3 Lawrence Street, Blackburn South VIC 3130. 03 9878 4800

Merlin Audio Design: 28-30 Essington Street, Mitchell ACT 2911. 026253 9777

Lenehan Audio: Factory 10, 185 Currumburra Road, Ashmore QLD 4214 PHONE:(07) 5564 5596, MOBILE:0418 765 726;

Plessis Valve Amplifier Model A

Sounds like the band is right there ...

Peter Familari found an amplifier so good he thought the band was in his loungeroom!

Review Published in Melbourne Herald-Sun

Sydney's Charl Du Plessis and his team studied a pile of leading amplifier designs before homing in on the eye-arresting Model A integrated valve amplifier. "We used topologies from those we thought sounded good and combined them with our own ideas of what makes a well- priced, superlative sounding valve amplifier," he says.

The result is great news for music lovers because along with the $4999 Model A, Plessis Audio also build a $1599 transistor model called the S1. Both are now on the market and music lovers like what they are hearing. But while the cheaper transistor amplifier performs well above its price point, the model poised to ring an audio enthusiast's bell is the valve studded Model A.

The design brief for this triode/ultra-linear amplifier was simple: build a user friendly tube amp that is sonically stunning and has civilized user features.

Along with foolproof biasing that feeds the valves the required voltage, the Model A carries a retro-looking meter that measures the hours clocked up by the valves. On the rear, a small switch allows users to set the Model A running in your choice of either Triode or Ultra-linear mode.

In Triode the Model A puts out a modest 20 watts per channel, and climbs to forty watts per channel in Ultra-linear mode. Since Triode, if done well, is the preferred audiophile route to musical bliss, we flipped :the switch to T mode and used the Model A to drive a pair of ProAc's Response One SC near- field monitor speakers.

CD player used was Arcam's giant killing 33T. Shunyata supplied the Aries interconnects, Phoenix speaker cables II and Hydra-II power filter.

Within an hour of warming up, the Model A was producing a wide and deep sound .stage, on which performers were arrayed with pin-point accuracy.

Tonally, the Model A was pure and natural, so much so that the gear retreats into the background leaving the listener believing the performers are playing live in the room.

Though the Model A's power output in triode mode looks meagre on paper, it is clean and undistorted and more than adequate to power the ProAcs to comfortable listening without running out of steam.For those who want to crank up the volume, the Model A doubles its power when switched into ultra-linear.Build quality is substantially high internally and externally, as is the perceived and sonic value of this amplifier.

Specifications - Model A

Configuration: Integrated Valve Amplifier

Inputs: Four, line level.

Power Output: 40w in Ultra Linear, 20w in Triode.

Tubes Used: 4 x EL34 (6CA7), 2 x ECC81 (12AT7), 2 x 6N8P

Frequency Response: 8hz - 82Khz at -3dB

Special Features: Easy Bias Adjustment, Usage Hours Counter, Military Grade Components, Special Transformers, Cast Chassis, Heavy Duty Binding Posts (4 & 8 ohm).

And then, there's the S1

Plessis Amplifier Model S1

Review from Audio-Video Lifestyle, by Nic Tatham.

NOTE: This review, previously up in pdf form is now done in text only, as the pdf has been causing problems.

There are a few theories being put forward why 2-channel hi-fi equipment is once more all the rage. In a day and age of newly emerging formats and multichannel, high definition audio and video, stereo and stereo hi-fi gear is still doing very nicely, thank you very much. This no doubt keeps the audio 'purists' happy but it's not necessarily the diehards that are keeping the 2-channel ball rolling.

If not they, then who? One theory that I heard lately was that it's thanks to the iPod. Surely 'proper' hi-fi's sworn enemy can't be responsible for increased sales in stereo audio equipment, but believe me, in this industry, stranger things have happened. Just look at vinyl, which is enjoying a healthy revival, over 20 years after CD was meant to kill and bury it. DVD was to do the equipment review same for VHS, but one of the bestselling machines at the moment are the DVD/VHS combos.

Whatever the reason, the underlying factor behind this popularity and resurgence is simply because when it comes to listening to music, two channels are enough. That's the crux of the iPod theory, and that when iPoders take their headphones off they are hooking up the little white devices to component hi-fi systems to listen to music in the home.

And you could happily plug your iPod into an amplifier such as this, although I have a feeling this particular integrated stereo amp will appeal more to the audio 'purist'than typical iPod wearer. The Plessis Audio S1 is one of a relatively new breed of hi-fi product - audiophile grade products that are made in China. Despite the nation's ability to mass-produce, it's also fast gaining international recognition for quality and also value of certain products - especially hi-fi. This particular amplifier is one of currently just two models from Plessis Audio. Charl Du Plessis is the man responsible for its design and the other Plessis amp - the valve integrated Model A has already picked up our Best Buy award this year. The S1 is a transistor-based design, line-level and no frills, at least on the outside.

Like it's valve studded partner, the S1 came aboutas a joint effort between Charl Du Plessis and his manufacturing partner in China. The design brief was to come up with an amplifier that delivered great sound quality at a really good price. During its design and development the S1 was compared to see how it stacked up against several other amplifiers from both Chinese and Western manufacturers.

Much thought and emphasis was placed on the quality of the individual components that make up the S1 and it contains a large number of Japanese-made components, many of them military-grade spec. The main transformer, for example, is a large oval-shaped device which is encased in ceramic and the entire power supply has been kept separate from the preamp stages and printed circuit boards (PCB) to help reduce the risk of any interference to the audio signal. I popped the lid off and had a look at the internal layout and it's obviously been done with a lot of thought paid to the topology between the various components. The volume control and input selector, for example, have been directly coupled to the PCBs which shortens the signal path and minimises loss.

The S1's specs suggest a healthy output and it's rated to deliver 80 watts RMS into 8 ohms and 130 watts into a 4 ohm load. The frequency response is stated at the extremes of the spectrum also covering a full bandwidth from just 5Hz to a skyhigh 110kHz. These figures are well beyond the range of the human ear but with formats encoded with such wide frequency bandwidths, such as Super Audio CD, it's definitely beneficial to performance if the hardware can handle them. There are just four line-level inputs, all unbalanced and true to any minimalist design, no tone controls.

The S1 only has the one pair of loudspeaker terminals, which are large, high quality 4mm binding posts and sockets. The front controls are a rotating power switch, headphone/ speaker switch, large volume control, input selector and a mute flick switch. There is some armchair friendliness provided by a small slim remote control that provides volume, mute and stand-by controls. Each S1 also comes with a Plessis Audio T-shirt so you can wear the fact that you're a proud owner.

I spared no time in hooking the S1 up to my hi-fi system so it had a few days of running and burning in before getting down to any serious listening. I always take note of how a product sounds straight out of the box because it not only forms a telltale initial impression of what's instore, plus you can gauge how much the equipment improves with use.

The early signs from the S1 were very encouraging. Part of its design was to be able to cope with tricky or demanding speaker loads and this amp's stated to be able to handle between 4 and 16 ohm impedance. I still had the big PMC IB1S studio monitors in place (see page 54) so Ifigured an accurate speaker and 4 ohm load such as these would be a great place to start testing these claims. Let me just point out that this as a $1,600 amplifier coupled with an $11,200 pair of professional loudspeakers. It's not the sort of amplifier these 500 watt PMCs would normally be driven by, but I wanted to see how the S1 coped. It's a gutsy little amplifier and the 4 ohm PMCs didn't stress it out in the slightest. In fact I was quite surprised at how effortlessly it drove the big PMCs, pushing them to substantial volume levels without any hint or sign of duress. Speakers such as these are normally partnered with some hefty amplification but credit where it's due, the S1's 130 watts at this impedance were doing the job nicely.

Switching to more conventional speakers and the sort that do partner this amplifier well, the S1 was more at home with my Quad 11Ls and KEF iQ9s. First up, the little Quads whichthrive on the end of decent amplification. These speakers never cease to amaze me and they can sound superb with the right amplifier in control. My initial impression was of a forthright and quite revealing sound and there's a definite balance achieved between musicality and involvement. Given the price, the S1 may not have the finesse or sheer transparency of dearer pre/power amplification but it puts the asking price where it counts the most - into the sound coming out of the speakers.

I also have an excellent 50 watt integrated amplifier from an English brand that is sadly no more - Audiolink,and this amp has served me very well over the years. Compared to this the Plessis S1 is a far more enjoyable listen and provides a great deal more music than the chrome-plated Audiolink could ever dream of. This 80-watter sounds as substantial as its impressive build quality. What's more it never sounds overblown or biased towards any particular sound characteristic - it's revealing without being dry, detailed without sounding too obvious and neutral without sounding weak. In a nutshell, it sounds as pleasant as your choice of music.

Heavily processed pop and rock tracks still sound edgy but the S1's bass warmth counteracts even the harshest recordings to an appreciable degree. It doesn't mind a challenge either such as Soundgarden's No Attention with its full-bodied bass and Chris Cornell's growling vocals, the amp has no trouble unravelling it all, keeping the voice in focus without holding the bass in check. Another striking feature is the openness and airiness of the sound evident with discs such as Beck's Guero. There's an excellent sense of space and ambience and the instruments have both natural timbre and superb bite, adding to the album's Hispanic musical flavour.

Switching to large-scale classical works and the S1 continues to impress. It delivers pieces such as Nielsen's Symphony No.6 with enough power and scale to do the dramatic music justice. The quieter passages are relayed with fine detail and you receive all the passion and intensity of the piece, powered along with snarling brass, shimmering strings and majestic scale. This is a music-lover's amplifier but just make sure you don't have too many sources as the S1 isn't the best equipped.

With limited inputs this is the sort of amplifier for someone wanting to listen to CD or Super Audio CD music in stereo with the minimum of fuss. Partner it with quality source and speakers and enjoy the music. AVL.

Ancillary Equipment: Teac VRDS-10 CD player, Musical Fidelity X-DAC, Quad 11L loudspeakers, KEF iQ9 floorstanding loudspeakers, PMC IB1S loudspeakers, SAP Relaxa 1 isolation platform, Wasatch Cable Works interconnects, Nordost Silver Flatline loudspeaker cables, Concorde and U-Build equipment supports, Black Box mains conditioner.

T e c h n o t a l k

Product Type: Integrated stereo amplifier

Number of Inputs: 4 x unbalanced, line-level

Power Output: 80 watts RMS (8 ohms); 130 watts RMS (4 ohms)

Total Harmonic Distortion: 0.066% (1kHz, 80W, 8 ohms); 0.066% (10kHz, 80W, 8 ohms)

Gain: 38.3dB

Signal To Noise Ratio: 97dB (without weight))

Frequency Response: 5Hz-110kHz (-3dB, 80W)

Load/Impedance: 4-16 ohms

Input Sensitivity: 300mV (line-level)

Input Impedance: 73 kohm (line-level)

(Technotalk specifications and recommended retail prices are supplied by the manufacturer)

Vital Statistics

Dimensions: 430 x 80 x 330mm; Weight: 10kg; Price: $1,599;

Distributor: Plessis Audio PO Box 566 Lane Cove, NSW 2066; Telephone: 0411 744 417 Facsimile: (02) 9904 8283 email:

Peter Famileri - From the Melbourne Herald-Sun

Troll into any half-decent audio shop these days and what you'll see is a growing number of buyers auditioning traditional stereo equipment. Take it as given, with SACD and DVD-Audio faltering, stereo systems that are built around CD and LP are back big time. To address the growing demand, Plessis Audio the brand behind the stunning triode valve amplifier reviewed in Connect a little while ago, have released a mid-priced, audiophile-quality transistor amplifier called the S1. Priced at $1699, the S1 may be what music lovers on a tight budget have been waiting for - a mid-priced stereo amplifier with a top-shelf sound quality.

While it may look like a plain vanilla stereo integrated amplifier, without even a couple of meters on the facia it's filled with audophile-quality military-grade components. Good housekeeping is evident throughout the circuit and extends to the hefty ceramic-encased power supply that is kept separate from the printed circuit board and preamp stages to prevent interference. It has plenty of grunt and is said to put out 80 watts a channel into speakers presenting a nominal 8 Ohm load and 130 watts a channel for those that average 4 Ohms.

On the rear the S1 carries four line output connections and a single pair of sturdy speaker terminals built from high-purity copper and finished with gold-plated composites. Externally the S1 is sleek with a well-finished slimlinel profile. Plessis also equips the S1 with one of the nattiest credit-card sized remotes used to operate volume, amplifier mute, power on or standby. The S1 is an articulate and musically satisfying amplifier with a performance way above its price point. The packing includes an informative manual and - in a nice touch a Plessis Audio T-shirt.

The S1 was used with Arcam's CD33T CD player, ProAc's Response One S loudspeakers and wired with Shunyata Aries interconnects and Phoenix speaker cable. Power filtration was Shunyata's Hydra Two. The S1 conveyed music with bags of refinement. The overall sound also had scale and authority. And while vocals were smooth and detailed, the S1 had plenty of venom when it had to reproduce the sharp leading edges of brass instruments.

While the S1's sound is musical and involving, it trades off ripping dynamics for a relaxed sound. At this price-point you can't have both. But if the S1 is matched to enthusiastic speakers such as ProAc's Tablette, the result is an exciting sound with long term musical satisfaction guaranteed.

Specifications - Model S1

Solid State Amplifier. with remote control for volume, on/off, mute.

Four Line Level Inputs; Headphone Socket; High Quality Speaker Binding Posts

Power: 80w per channel into 8 Ohm load, 130w per channel into 4 ohms.

Frequency Response: 5hz-110Khz +-3dB

THD + N less than 0.06% at 1Khz fully driven

Build Standard: manufactured by speciatlis Beijing factory which has QA to Military & Industry Standards

Design Criteria

Notes By Charl: With the S1 we set out to build an amplifier at an affordable price, but with performance way in excess of the usual offered at this price. I knew that this was asking a lot, but read on. During design and development we compared the S1 to various well known brands like Red Rose Music, Korsun, Audio Space, Shanling, Consonance, Vincent, Jolida, Musical Fidelity, and others from the Chinese and Western markets.

The componentry selected has been rigorously checked - the main transformer is a critical item and was selected on the basis of being Accurate, Fast and Efficient. We had the opportunity to select from both Chinese and Japanese (there are quite a few Japanese parts in this amp) manufactured components, emanating from suppliers to the military and major industrial users. This enabled us to maximise the quality of our product. We designed our own power supply to avoid the common error of using a ready made but less efficient and noisy one!

We also took care with the physical layout of the amplifier. The ceramic encased power supply is completely separated from the Printed Circuit Boards (PCB) and pre-amp stages. The volume control is direct-coupled to the PCB to shorten the signal path and minimise losses. Similarly, the input selector is direct-coupled to the PCB, again minimising signal paths and reducing the possibility for induced distortions or noise. The Speaker binding posts are of the best quality, combining high purity copper and gold plating in a heavy duty post not seen at this price level but well liked by audio people.

In the final analysis, this had to be an amplifier that creates musical magic - but to do it at a price which makes this magic available to many more people.

Note: Len Wallis Audio had one of these in their secondhand listing online for $820, which would be a good buy!