The Icon Audio MB 150 Mono Bloc Amplifiers

A very powerful, traditional design, where power, warmth and dexterity are required

Super KT 90s in Parallel Push Pull
Designed in Leicester by David Shaw, founder of Icon Audio. Following on the heels of our acclaimed MB845s, our new MB150s are a 3 stage design, the front end is inspired by the Leak “TL” designs. We have used the older bigger 6SN7 driver valves from the early 1940’s. These have a reputation for a richer more textured sound, reliability, and a very long life. This combination of traditional design, excellent valves, audiophile components, hard wired, no PCB, custom transformers, massive choke regulated power supply with beautiful looks all add up to a stunning combination!

The power output stage uses the super GEC KT90/88 probably the greatest all round hi fi valve, operating in both “Ultralinear”(150w) and Triode mode (100w) to give the maximum choice of operating conditions. Effectively giving you two amplifiers in one! 150 watts of valve power is easily comparable with 300 watts of transistor power and will drive almost any sensitivity of speakers well, leaving plenty of headroom for dynamics and low distortion. The large custom wound transformers are able to deliver very deep bass notes and smooth clean treble.

Close attention has been paid to the large power supply using eight large capacitors and a large “choke” in a traditional “Pi” configuration. This gives very low source impedance with a huge reserve of power available for large transients without clipping.

This combination gives a very smooth and detailed sound stage which works well to bring out the colour
and texture of older recordings and whilst not overemphasizing the harshness of many modern
digital recordings. This makes for a very easy to live with amplifier that has the power to control modern
speakers.

The Icon Audio all new MB 150 Mono Blocs

DID YOU KNOW? Two KT90s in class AB1 produce as much “Class A” as a pair of KT66/300Bs in pure class A,
but more than twice the power in AB1. And their low idle current causes much less stress on the tube. As it is less than 50% of the maximum rating! Preserving tube life.

Surprisingly from such big amplifiers is how well they perform at low powers. Their agility and detailed texture of strings and vocals is quite astounding. A feature of the MB150s is the high and low sensitivity. This enables MB150ss to work with both “Passive” and conventional pre amplifiers. This is not done by the usual attenuation which increases noise and reduces quality, but genuinely changes the sensitivity (or gain) of the input.

Another feature of the MB150s is the power saving “Warm up/Standby” switch. This prevents valve cathode stripping during start-up and enables the amplifier to remain in standby on low power without wasting valuable valve life or electricity (only 50w). The amplifiers will then start instantly, fully warmed up.

The brand new design features painted heavy gauge steel chassis, 20 mm solid alloy front panel. And our famous Plexiglas valve cover to create a stunning visual impression. On the scales at 50Kg (pair) this amplifier is no lightweight in quality or performance and should give many years of excellent service.

As each amplifier is prepared to your order here in Leicester. We can offer a range of upgrades including our unique HT delay, premium and “new old stock” valves, the superb Jensen Copper foil “oil in paper” capacitors. Ask us for a quote.

Specifications and Features

• Comprehensive manual supplied
• Full instructions for valve change included
• All hand wired point to point
• No printed circuit board to ‘colour’ sound
• Class A, all Triode front end
• Output circuit Ultralinear or Triode switchable*
• 8x KT90/KT88 precisely matched for best performance
• 4x 6SN7 phase inverter valves
• Standby switch to prevent cathode stripping on startup
• Standby switch to save valve life and power only 35w
• Optional automatic HT delay to prevent cathode stripping
• 150w RMS continuous per channel
• 100 Watts RMS in Triode mode
• Signal to noise level -100db
• Freq response better than 20hz-20kHz +0 – 0.5db
• Total harmonic distortion typically less than 0.1% 1khz
• 4 & 8 ohm loudspeaker taps
• Japanese steel EI transformers with low oxygen copper
• Attractive valve cover included in the price
• High quality 2W metal film, & wire-wound resistors
• Blue LED mains indicator
• Polypropylene audio capacitors
• Silver TEFLON audio cable
• Custom hand wound output transformers
• Big custom wound PSU Choke
• Ceramic valve holders for minimum leakage
• Centre tapped heater circuit for minimum hum
• ‘Soft start’ device incorporated
• Gold plated Input & speaker terminals
• 400mv (high) & 1200mv (low) input sensitivity.
• 230/240volts ?watts approx (115v available)
• Consumption: ?w standby, ?w quiescent, ?w Max
• C E, ROHS, WEEE compliant where applicable
• Size in mm W?, D?, H? (? inc cover), 23kg each
(overall. Allow space for connections and ventilation)

(Provisional leaflet. Please note at the time of printing some specifications were not confirmed Specifications subject to change, errors & omissions excepted. General 25/09/09)

Downloads

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

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