The new Icon Audio Stereo 40

Launch of New Stereo 40i “Classic”

With the launch of our new Stereo 60 and Stereo 300 amps, we have taken the opportunity to do a few upgrades to the Stereo 40i. These include: Incorporating a large “Choke” to make the background even more silent. Adjusting the driver circuit and reducing feed-back. Changing the valve line-up so we can now offer an “all Mullard” version.
At still only £899.95 with European valve upgrade, the Stereo 40i Classic is exceptional value for money!
Our Stereo 40i (EL34) has a enviable reputation following the outstanding reviews in Hi Fi News and Hi Fi Choice also winning “Editors Choice” award in Hi Fi News two years in a row. We are now delighted to announce new KT88 & KT66 versions by popular request! Whilst the Mullard EL34 is without a doubt the best value and all rounder in power output valves, pre-dating this a new standard was set by GEC in the late ‘30s with their “Kinkless Tetrode” the KT66. Having very low distortion and a more ‘refined’ sound compared to the EL34, its lower output and smooth sound would lend it more towards bringing out the fine detail of the best recordings. In 1957 the KT88 was the final development of the audio output valve by GEC having the highest power rating and probably the cleanest sound of any valve available. Very dynamic & solid sounding, still with warmth & colour it is probably the most neutral sounding valve.

Building a valve amplifier is relatively easy, the difficulty is getting it to “hang” together well. We use tried and tested circuits excellent transformers and have refined them further with top quality components, solid build quality and stylish looks to give amazing sound quality and performance at many times the price.
We even give you the choice of either 40* watts in Ultralinear mode or 20* watts in Triode mode (KT88) with its more relaxed sound quality. Almost like two amplifiers in one.
What’s the difference?
All early valves were triodes (three elements), They are highly regarded for their smooth, musical qualities, but lack the higher power of pentode valves.

We also like to keep things simple without circuits like tone controls, filters, balance etc which can affect the purity of sound (even when not in use), that way the delicate audio signal has the shortest path and less chance of degradation.

In recent years it has become accepted that a good specification on ‘paper’ in no guarantee of a good sound. E.G. lots of modern ‘solid state’ equipment  sounds ‘harsh’ and ‘clinical’, losing natural ‘warmth’ and ‘colour’, with the dreaded ‘listening fatigue’ which can ruin your listening pleasure after a short while.
We developed the Stereo 40 with the following design criteria:
1, To have a musical, easy listening, “warm sound”.
2, Having adequate power to drive modern speakers to a good volume level on all types of music.
3, To have a total absence of ‘listening fatigue’
4, To work with any modern input source.
5, To be reliable and easy to live with, using easily obtainable valves. (All the valves we use are in production).
6, Easy for owners to do a valve change if required.
7, To have excellent build quality.
8, To be excellent value for money.

We have not used primitive Chinese circuits, but have developed our designs and refined them over time based upon the excellent research and ideas by Mullard, GEC and Williamson in the 1950’s, to mirror the traditional British designs using modern audiophile components.
Most importantly we consider HARD WIRING very important as this has advantages for cool running, simple service and easy upgrade. With no expensive printed circuits to burn out and bullet proof build quality. This method of high quality construction ensures the shortest signal paths, low impedance, low capacitance, low inductance signal paths, with low noise, which promote clean sound quality. Nothing gets hot under the chassis and therefore component life is prolonged.
The amplifier is built to last a life time.

Operating in ‘Ultralinear’* ‘push pull’ mode, the Stereo 40i gives around 40 watts output of beautiful valve sound. Triodes are generally recognised as giving the best sound, but when used as output valves triode amps are usually expensive and low powered. Now at the flick of a switch the EL34/KT66/88’s will also perform beautifully as triodes giving around 20 watts*, which is usually ample power for average efficiency speakers, remembering that valve watts work out to be about double those of transistor amps. Using a ‘passive’ pre amp with the famous blue ALPS volume control to preserve the purity it is sensitive enough (350mv) to work well with any modern input source. TV & video etc.
*Halfway between pentode and triode

Speaker matching
With 4 & 8ohm taps the Stereo 40 works well with virtually any modern or vintage conventional speaker.

Sound Quality
The STEREO 40 offers a very open transparent detailed sound stage, which is warmer, and more involving than solid-state counterparts. The sweeter treble makes for very easy listening, whether jazz, classical or dance music. The bass is has more “timbre” and is capable of delivering power down below 20Hz (see Hi Fi Choice Review). A big plus is the amazing way that small details may be heard in complex passages.
The Stereo 40 is all ‘analogue’ and sounds great with any source inc LP’s, FM radio and tape, it will also ‘calm’ digital sources such as CD, MP3, DVD etc.

Why ‘Push Pull’ output and not ‘Single Ended’?

STEREO 40i construction

We use a polished stainless steel chassis, chosen for its non-magnetic neutral sonic qualities. The front plate and transformer cover are 10mm solid anodised alloy plate. The transformer housing is sectioned inside to eliminate noise between transformers and has an enamel crackle finish. Underneath the chassis there is a painted steel sub chassis. The knobs are gold plated alloy. It is supplied with a very attractive valve cover, (see photo).

This gives you an amplifier with excellent performance that has superb build quality, it is easily upgraded, and easily serviced. We keep a full range of spare parts in stock.

Input and output terminals are audiophile gold plated RCA phono and oversized speaker terminals, which will accommodate the largest of cables as well as banana plugs.
Only one capacitor per EL34/KT66/88 is used in the signal path. These are high quality Solen polypropylene. Resistors are oversized 2w metal oxide and wire wound chosen to suit their application.

The unique attractive cover made from stainless steel and high density Perspex gives added protection for more vulnerable situations whilst retaining good looks.

Valve Life
We have recently tested the valves in several models over 5 years old and found them to be good condition. We would recommend out HT delay to extend this.
Replacement valves

Icon amplifiers only use valves currently in production. This gives you choice & keeps the price low. Current cost is under £95 for a matched set.

Specifications and Features

• Comprehensive manual supplied
• Full instructions for valve change included
• All hand wired point to point
• Choke regulated power supply (“Classic” only)
• No printed circuit board to ‘colour’ sound
• Japanese Blue ALPS volume pot.
• All Triode front end
• Output circuit Ultralinear or Triode switchable*
• 4x EL34, KT66 or KT88 output valves
• EL34/KT88s precisely matched for best performance
• 2x 12AX7 (ECC83) first stage valves
• 2x 12AT7 (ECC81) phase splitter valves
• HT delay to prevent cathode stripping (optional)
• 2x 45w KT88, 40w EL34, 30w KT66 RMS per channel
• 2x 20/19/15 Watts RMS in Triode mode
• Signal to noise level -90db
• Freq response 20hz-20khz +0 - 1db
• Total harmonic distortion typically less than 0.2%
• 4 and 8 ohms output taps
• Japanese steel EI transformers with low oxygen copper
• Attractive cover included in the price
• Minimal feedback used
• High quality 2w metal film, & wire-wound resistors
• Blue LED mains indicator
• Polypropylene audio capacitors
• Silver TEFLON audio cable (not SE/e)
• Ceramic valve holders for minimum leakage
• Centre tapped heater circuit for minimum hum
• Pre-amp 6.3v heater circuit floated at 60v to minimise heater-cathode leakage
• ‘Soft start’ device incorporated
• Supplied bias test meter
• Polished stainless steel chassis
• 10mm solid aluminium front plate & transformer cover
• Gold plated Input & speaker terminals
• Inputs for CD, Tuner, Aux & Tape
• Tape monitor circuit* (not ie)
• 350mv input sensitivity.
• 230/240volts (also 120v), 135watts 1.6A anti-surge fuse
• C E certified
• 320W (380), 250D (340D), 180H (240), 14.6kg (figures in brackets allow for rear connections & ventilation)

Downloads

For full details of this product (including options and delivery details) pls download the PDF and Word doc.

PDF Word.doc