Icon Audio ST40 MkIIIm Integrated Tube Amp
Eight-Tube Midrange Valve Amplifier Unique in Build Quality, Visual Presentation, Versatility, and Feature Set
Tremendous Warmth, Rich Tonality, and Truthful Balances, Plus Ability to Use Extremely Wide Range of Tubes
Icon Audio designed the handmade ST40 MkIIIm integrated tube amp with one goal in mind: Make it the best-possible midrange EL34/KT88 valve amp available in its price class. High-end audio companies frequently make similar boasts about their products and aims. But Icon is different. Really. The company and this component back up the humble brag via design excellence, performance execution, and dedicated support. Not only is the ST40 MKIIIm a glorious-sounding piece, it's unique in build quality, visual presentation, versatility, and feature set.
The eight-tube, 40W-per-channel ST40 MKIIIm possesses the requisite warmth, rich tonality, and truthful balances every listener expects from a tube integrated. Tremendous sonics are a given here. But this English beauty gives you much more. It's nearly alone in its ability to use a wide range of output valves (EL34, KT88, KT66.77, 6CA7, 6550), allowing music lovers and tube rollers unheard-of customization options. The ST40 MKIIIm also boasts a Valve Rectifier. Normally only fitted to extremely costly amps, the device is renowned for producing very smooth sonic characteristics.
From aesthetic and manufacturing perspectives, it is equally impressive. Like all Icon amps, the ST40 MKIIIm is entirely point-to-point hand-wired and contains no printed circuit boards or transistors, which degrade valve performance and color the signals. A cool built-in meter both adds to the classy, vintage look and serves multiple purposes, telling you when the output valves needs replacing as well as if they're operating at maximum potential. It's all in the service of ensuring that you're hearing music in the finest-possible sound. Along the same lines, the tertiary transformers have a third winding that reduces distortion and global feedback by almost 40 percent.
An all-Triode front end, remote control, choke-regulated power supply, record loop, operation in either triode or ultralinear modes, plexiglas valve cover, 2" solid alloy front panel with polished dark-alloy chrome knobs, and gorgeous metallic paint work are also standard. Icon takes any worry out of the purchase by providing a two-year parts-and-labor warranty and full service and support for the lifetime of the product. That's how it should be, and while most competitors don't go to such extremes, Icon is happy to do so.
EL34 or KT88? The ST40 IIIm is designed to work with a wide range of output valves. You can choose between EL34 or KT88 (select from the menu above). It will even work with KT66/77, 6CA7, or 6550 tubes. So, you can experiment in the future and get the sound best for you.
Ultralinear or Triode? For 60 years, audiophiles have argued which sound is better. With the ST40 IIIm you have the choice of both at the flick of a switch. It's like having two amplifiers in one! Most hi-fi fans prefer the sound of triode valves, especially for acoustic music.
Where does it fit in? The ST40 IIIm is a versatile midrange amplifier designed to get the best out of the popular EL34 and KT88 valves. Its low distortion and excellent bandwidth will drive a wide range of modern and older speakers very well. An excellent alternative to a transistor amplifier, and more detailed and revealing with a warmer heart, the triode performance rivals that of expensive triode valves like the 300B.
- The Valve Rectifier provides a very smooth sound, normally only fitted to very expensive amplifiers.
- Choke Regulated Power Supply: Working with the valve rectifier the large choke gives super-smooth power regulation for a silent background.
- Tertiary Transformers have an extra (third) winding which reduces distortion, using less feedback.
- 6SN7 and 6SL7: Far better than their miniature cousins, these larger older valves are the best in their class for their musical sound and longer life.
- Remote Control: It’s hard to get exactly the right volume in your listening position. Now you can make fine adjustments anywhere.
- Comprehensive manual supplied
- Built in meter "Easy Bias" system
- Full instructions for valve change included
- All hand wired point to point
- No printed circuit board to 'color' the sound
- Japanese ALPS volume pot.
- Class A, all-Triode front end
- Output circuit Ultralinear or Triode switchable
- 4x EL34/KT88 precisely matched for best performance
- 1x 6SL7/6N9 first stage valve, 2x 6SN7 phase splitter
- 274B/GZ34 valve rectifier for ‘Soft start’ and smooth sound
- Standby switch to save valve life and power
Icon Audio gear is engineered in the UK and manufactured in China, with final assembly and checking done in the UK. Warranty on all Icon Audio pieces is 2 years, parts and labor. Tubes are warranted for one year on a pro-rated basis.