Pure Sound A30
tube integrated amplifier

The Pure Sound A30 amplifier was developed to meet the demand for an affordable Class A amplifier that would be compatible with all types of loudspeakers. Class A operation was chosen because it gives lower distortion and a more relaxing, natural sound.

Pure Sound A30

The Pure Sound A30 amplifier was developed to meet the demand for an affordable Class A amplifier that would be compatible with all types of loudspeakers. The A30 is a line level integrated design that allows for the selection of up to 3 different source components and control of the volume by a high quality ALPS Blue Velvet potentiometer. Class A operation was chosen because it gives lower distortion and a more relaxing, natural sound.

The amplifier uses the very robust Electro Harmonix 6550 output valves in an Ultra Linear Push Pull configuration. This arrangement gives a combination of power and clarity that is difficult to beat. The amplifier uses an Auto Bias system, which means that replacement output valves should be fitted as matched pairs. There will be no need to reset or monitor bias conditions.

Very high quality components are used throughout including selected carbon film resistors and SCR polypropylene capacitors. The power supply makes use of twin valve rectifiers and choke smoothing.

The output can be configured for use with 4 or 8 ohm loudspeakers.

The output stage can also be switched to triode-coupled configuration. This further linearises the operation of the valves at the expense of some output power. It may be preferable with higher sensitivity loudspeakers.

The A30 may also be used as a very high quality stereo power amplifier if the volume control is turned up fully.

When partnered with appropriate ancillary equipment the A30 is capable of very satisfying performance.

Why this amplifier? Why now?

With the recent interest in lower powered Single Ended triode amplifiers has come the realization that to get the best from these, the speakers used have to be both sensitive and quite large to give truly satisfying results. There are also not that many good, high sensitivity (>97 dB/W) designs available at any price never mind at price levels the majority of music lovers can afford.

However, there are some very good loudspeakers currently being made with sensitivities between 88 and 94 dB/W. These are sufficiently revealing to make the virtues of simple, high quality amplification readily apparent, although in most cases the output of a typical single ended amplifier is insufficient to give the scale and drama many types of music demand.

A good amplifier with 25 -30 watts of output power is more than enough to drive this type of loudspeaker to sensible levels even in quite a large room. For simplicity a valve amplifier is preferable. Recently, there has been an increase in the number of relatively affordable valve amplifiers made in China. Many of these are compromised by the quality of their transformers, components, layout and because they operate in Class AB or B to give a higher power specification. They often also use a lot of negative feedback in an attempt to compensate for these shortcomings with a consequential impact on clarity and low frequency control.

For some 10 years there has been a lack of affordable Class A valve amplifiers.

The Pure Sound A30 operates fully in Class A up to its rated output so it does not change character at any signal level. There is none of the distortion caused by output devices switching on and off and therefore no requirement for excessive feedback to correct for it. The 6550 valves supplied are the extremely robust Russian Electro-Harmonix variety and are quite content with dissipating the power required to maintain Class A operation up to 30 Watts.

The valve rectifiers used keep the high voltage power supply clear of the noise that can be introduced by silicon rectifiers. A substantial choke is also incorporated to keep the power supply impedance low.

The output transformers also give extremely wide bandwidth allowing very solid low frequency performance as well as exceptional reproduction of timbre.

These design features combined with the use of high quality passive components, octal based input and driver triodes and an elegant but simple internal layout results in an amplifier which sets a new benchmark for performance, build quality and value.

Class A operation
• 3 Line level inputs
• 30 Watts per Channel Output
• 4 and 8 ohm output taps
• Twin valve rectifiers
• Choke smoothing
• ALPS potentiometer
• SCR coupling capacitors
• Carbon film resistors (for better sound quality)
• Electro Harmonix (Russia) 6550 output tubes
• Very substantial construction including cast metal transformer shrouds.

Product Review:

HiFi.nl, Rene van Es, Februari 2009
"In de inleiding vroeg ik mij af, of alwéér een buizenversterker wel nodig was en of mijn Engelse collega’s de waarheid spraken. Over het eerste standpunt valt te twisten, met het tweede ben ik snel klaar: ze hebben gelijk. De A30 versterker is niet alleen esthetisch mooi, hij speelt eveneens heerlijk."

HiFi+ issue 48
The PureSound A30 amplifier earned a 'Product of the Year' award in issue 48 of HiFi + magazine.

Alan Sircom in HiFi+ issue 48 :
Sonically there's nothing to touch its combination of musical integrity and authority at anything like the price.

Hifi + issue 52
Chris Thomas in HiFi+ issue 52:
The PureSound performed so incredibly well that I completely forgot that I was listening to an amplifier that costs a little over a £ 1000. Where this amplifier scores is in its impressive musical coherence across the bandwidth.
The pure Sound positively drips with the ambience of the event and has a musical presence and range of tonal colors that sets it apart from the crowd.

HiFi Choice October 2007, (pdf-file)
Black magic, Pure Sound`s first amplifier is able to cast a spell its listeners

AUDIO Sept. 2007
AUDIO Prädikat:
überragend, 100 Punkte, High End Klasse, 5 Ohren.

"Prachtvoll aufgebaut und bestückt, extrem feinsinniger, farbenreicher Klang"

Hi-Fi News, June 2009, (pdf-file)
The A30 fares very well in a group test of valve amplifiers featured in the June 2009 issue of HiFi News. These amplifiers were from a very broad price range and as one of the least expensive designs the A30 was felt to offer very good value. It was one of two of these amplifiers to earn a 'Highly Commended' rating.

"..it had that tremendous presence through the midband that, unlike the other amps, brought the orchestra right into the room."

Hi-Fi World, June 2009, (pdf-file)

The A30 received another favourable (if peculiar) review, this time in the June 2009 issue of HiFi World. The reviewer mistakenly spends rather too long on the issue of amplifiers designed around KT88's (which the A30 deliberately does not use!) but his subjective experience of the amplifier is very positive.

"..the A30 is an amplifier of enormous sophistication. It sets up a wonderfully rich picture of a performance that is full of lively fine detail free from any form of edginess, yet fluid in its progression and both easy and natural to the ear."

Hifi + issue 64, (pdf-file)
An excellent review of the A30 amplifier coupled with a Border Patrol power supply has appeared in issue 64 of Hi-Fi Plus.

6Moons.com online review
In February 2010 the online magazine 6 Moons published a very positive review of the A30. You can read this review by clicking the link above.

Price :
(including VAT)

Pure Sound A30

€ 2035.00


Pure Sound A30 NL version

Special NL version with upgraded Copper foil coupling capacitors, Amtrans and Shinkoh resistors.
€ 2355.00

NB. The factory that makes the A30 also makes the Bewitch amplifiers.
There is a Bewitch amplifier that looks just like the Pure Sound A30. The Bewitch 6550 is a 60 Watt Class AB amplifier which uses reduced bias current (hence it is a Class AB amplifier and can deliver more output power), different (smaller) output transformers and a different feedback circuit.

All Pure Sound branded products are made to our specifications.