This page has been a long time coming and to those of you who have never heard of the Soul Series, I hope you find the information within both interesting and thought provoking. If, on the other hand, you are familiar with this range of equipment, then this page may offer insight and hopefully answers to some of the speculation and myths concerning these exceptional products.

 

History

The Soul Series amplifiers were originally a concept idea between myself 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 tubes and directly coupled throughout.

The original signal circuitry was then drawn out by hand between Tom and myself, with all the control circuitry needed’ for the correct operation of the signal path added later to the main drawing’ but not before extensive testing of each circuit prototype. All prototyping of the finished circuitry was carried out by Tube Distinctions until its performance was accepted.

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 ‘noisey’ 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 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 an exceptional power amplifier to compliment its other range of products and at the time, Tube Distinctions already had a good reputation in the industry for making innovative valve/tube amplification/designs.

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 myself and Tom to go our separate ways.

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 listen-ability.

Measurements and Test Results

Arguably for once in single-ended audio history, with the Soul amplifiers you could have it all! Exceptionally high 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 audio frequencies with such speed and accuracy is incredible!

I have to agree the first time I listened to the finished prototype, I was gob smacked! 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 they thought the amp sounded like, 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. The soul series now has the addition of a new pre-amp – the Soul-Mate – is by far one of the best pre-amplifiers to date, at any cost and although it was designed as a perfect partner for the soul power amplifier range, it has been used with 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 supplying/supporting these products for many years to come and who knows, maybe by that time some of the other so-called high end audio manufacturers will have caught up and may also be able to offer some of the exceptional circuit topologies and extraordinary performance capabilities incorporated in every Soul Series product. In the meantime, Tube Distinctions strongly suggest that you ‘don’t hold your breath’ in anticipation.