Eight-Tube Stereo 40 MkIV Delivers Tremendous Warmth, Rich Tonality, and Truthful Balances: 50Wpc Integrated Amplifier Offers Switchable Ultralinear and Triode Modes
Icon Audio created the handmade Stereo 40 MkIV integrated tube amplifier with one goal in mind: Make it the best-possible midrange EL34/KT88 valve amp available in its price class. That included adding a headphone socket for increased flexibility, re-engineered output transformers and an enhanced power supply for increased instantaneous power for heavy transients, and an improved cascode-configured driver circuit for clearer definition. Able to output 50Wpc in ultralinear mode and 30Wpc in triode configuration, Stereo 40 MkIV allows you to change between the two options with a flick of the switch. Named a Hi-Fi News Outstanding Product, Stereo 40 MkIV is a glorious-sounding piece unique in build quality, visual presentation, versatility, and feature set.
Graced with four matched KT88 and four 6SN7/CV181 first-stage tubes, Stereo 40 MK IV 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-devised beauty gives you much more. It stands 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. Stereo 40 MkIV also boasts a Valve Rectifier. Normally only fitted to extremely costly amps, the device remains renowned for smooth sonic characteristics.
From aesthetic and manufacturing perspectives, Stereo 40 MkIV proves equally impressive. Like all Icon Audio amps, it arrives 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.
A Class A all-Triode front end, remote control with ALPS motorized pot, choke-regulated power supply, record loop, SCR audio caps, silver-plated PTFE cable, plexiglas valve cover, 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. Our 100% Music Direct Guarantee ensures your complete satisfaction.
"Now in MkIV guise and better value than ever, Icon Audio's latest Stereo 40 can take on both tube and solid-state amps at this price. It offers more power and control that you might expect from the former, plus a natural charm that one doesn't always associate with the latter. A real improvement on its predecessor, the Stereo 40 MkIV combines great sound with the bonus of Triode and Ultralinear modes."
—Hi-Fi News, Outstanding Product review
"It is well made, good looking, highly tweakable, surprisingly powerful and delivers an engaging sound. A great value package that will tempt serious solid-state amplifier fans with its valve charms."
—Hi-Fi Choice, Recommended review
- All hand wired point to point, no printed circuit board
- Class A, all Triode front end
- Output circuit Ultralinear or Triode switchable
- Suitable for 4, 8, and 16ohm loudspeakers
- Supplied with valve cover.
- Choke regulated power supply
- SCR audio caps, or Mundorf silver/gold in oil upgrade option
- Silver plated copper PTFE audio cable
- Custom hand wound Tertiary output transformers
- Audiophile Gold plated Input & speaker terminals
- Four line inputs: CD, Tuner, Aux plus Tape
- Tape monitor circuit with 'Record Out'
- Standby switch to save valve life and power
- Remote control with high quality ALPS motorized pot
- Comprehensive manual supplied
4x KT88 matched for best performance
4x 6SN7/CV181 first stage valve and phase splitter
2x 50w per channel Ultralinear output continuous
2x 30 Watts in Triode mode continuous
Signal to noise level: -90db
Freq response: >20hz-20kHz +0 – 1db
Power bandwidth: 30Hz-30kHz -3 dB
THD: 0.2% at full output
Power requirement: 115-120VAC, 76 Watts standby, 140 W Min, 240 W max.
Dimensions (WDH): 15.4" x 16.1" x 9.1"
Weight: 50.7 lbs.