History
The Soul Series amplifiers were originally a concept idea between myself [Anthony Matthews] and Tom Evans of Audio Design. The intention was to combine the expertise we had both gained from our very different but relative audio design careers. After many discussions and exhaustive prototyping of various circuit topologies, it was agreed that the signal circuitry would be a hybrid design, “Single Ended” class A with semi-conductor front end, driving Valves/Tubes in the output stage, and directly coupled throughout.
The next stage was to design a casework to house all the individual circuitry that would keep the integrity of the ‘form follows function’ topology that is a crucial element in the performance of the Soul amplifiers, with mains transformers, and other ‘noisy’ circuits (eg: rectification) and high current components kept well away from the very clean and sensitive signal circuitry needed for accurate reproduction of the exceptionally complex audio frequencies. Again this was another task accomplished by Tube Distinctions. In fact, the whole process from the first prototype circuits to the finished production models was carried out by Tube Distinctions…
Models
Originally it was decided that there would be five models as follows…
• 15 WATT STEREO
• 30 WATT MONO-BLOCKS
• 30 WATT STEREO
• 60 WATT MONO-BLOCKS
• 120 WATT MONO-BLOCKS
Although most models were produced (with exception of the 120 watt mono-blocks) it was decided after Tube Distinctions took total control over the production of the Soul Series [from 2004 on] that the models produced would be limited to just three types as follows…
• 15 WATT STEREO
• 30 WATT MONO-BLOCKS
• 60 WATT MONO-BLOCKS
Myths ‘Debunked’
There has been a lot said and misunderstood about the Soul Series products over the last couple of years, so much so that I felt it was time to put some of the myths and rumours to rest once and for all…
Marketing of the Soul Series
The main reason the Soul Series were sold and promoted under the Tom Evans Audio Design brand name and not under the company name that originally produced them (Hyperlinear Ltd) was purely because Audio Design needed a power amplifier range in order to compliment its other products, and at the time, Tube Distinctions already had a good reputation in the industry for designing and building innovative Valve based amplification.
Reviews
The first Soul amplifier to be reviewed was the smallest of the series – a 15Watt per channel prototype – and was presented to the very capable Roy Gregory of HI FI Plus fame. Needless to say, the review he went on to give the product said it all – he loved it! As stated, this was the smallest of the range and although a completed unit, it was still a prototype and development would continue until the first production models appeared for sale in 2003, by which time the performance of the product had reached another level and was far superior to the original review model. Read the original review here
The end of the road for Hyperlinear Ltd.
By the time the first production models appeared in 2003, relations between Tom and myself had become very tense to say the least. Therefore it was no surprise to some when it was announced that the company which had produced the first Soul power amps, Hyperlinear Ltd. was to be dissolved, thus enabling Tom and myself to go our separate ways.
2004 The Re-launch of the Soul Series amplifiers + the all new Soul-Mate Preamplifier.
After the sad but inevitable parting of the waves between Tom and myself, the Soul Series power amplifiers along with the addition of the all-new Soul-Mate preamplifier were re-launched in 2004, at the Heathrow HI-FI show under the Tube Distinctions Brand name. I produced three special red versions for the occasion, they were featured in the Overkill Audio room, powering the stunning Encore loud speakers, Read the six moons review….
Comparisons
Since the first Soul amps started appearing in magazines and dealers demo rooms, it was inevitable that they would be compared with other so-called high-end equipment that was thought to be worthy of their performance and relatively high price tag. Well, let me start by explaining some of the reasons why the Soul amps were and are so special and so different to most of the high-end amplification out there today.
Signal Circuitry
Single-ended, class A directly-coupled, non-inverting, semiconductor/valve/tube Hybrid…and that’s just for starters!!!
Single-ended…why?
Single-ended operation was chosen for the signal circuitry in all of the Soul Series products. Although the single-ended signal path is simpler in comparison to push-pull, it is all the more difficult to get it to work right. This is why most of the technology utilised in the Soul power amps is used in the control circuitry around the valve/tube. Tube Distinctions was already known for making excellent push-pull designs, but was always aware of the potential a well designed single- ended amplifier would have over push-pull in terms of Musicality.
The Soul power amplifier modules are significantly different from conventional Valve/Tube topology and design for a number of reasons, some of the main being; Directly coupled Signal circuitry, which utilises both conventional and surface mount components.
Heater circuits use unique and therefore bespoke technology in order to supply an accurate set voltage while maintaining ultra low heater to cathode noise. Screen grid voltages are also tightly maintained using discrete regulators.
Last but not least; Bespoke cathode current regulation, which meticulously maintains cathode current, despite the variation of valves that may be fitted by the user, therefore negating any form of adjustment needed when replacement Valves/Tubes become necessary.
Measurements and Test Results
Arguably for once in single-ended audio history, with the Soul amplifiers you could have it all! Exceptionally wide frequency bandwidth (typical 8hz to over 200khz) with incredibly low noise/distortion figures, and an amp that was phase flat to 60khz! Everyone who has had the pleasure of really listening to a Soul amp have come to the same conclusions – the amp’s ability to reproduce Musical information with such speed and accuracy is astonishing!
I have to agree the first time I listened to the finished prototype, I was taken aback! Another phenomena associated with the Soul amps, after people were given the chance to have a really good listen, they were then asked to give their opinions as to what if any particular bracket the Soul amps fitted into, i.e. Solid State, or Valve/Tube, all said basically the same, “it doesn’t sound like anything Solid state or Valve/Tube” it just sounded right!
Conclusion
When I decided to add the information contained in this page to the web site, my personal feelings were left aside, and what has been written just about describes the attributes of the Soul Series amplifiers, and of course a brief description of how they came to be. In 2004, the soul series amplification range had the addition of the Soul-Mate pre-amp, which was/is by far one of the best Audio pre-amplifiers to date, at any cost, and although it was originally designed as a perfect partner for the soul power amplifier range, it has’ over the years been used with many other types of amplification with exceptional results.
All that’s left to say is; thanks to all the customers who have invested their trust, judgement and hard earned cash into the Soul Series phenomena. I hope to be supporting these products for many years to come.
Thankyou!
“The Truth is like a lion; you don’t have to defend it. Let it loose; it will defend itself”
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