For much of the last year, Icon Audio founder David Shaw has, in his own words, been building his own birthday present. After discovering a quantity of ‘new old stock’ Russian GU81 transmitter valves, Shaw began to work on a prototype amplifier that would achieve a long-held personal goal: to effectively drive any modern low-efficiency high-end speaker to realistic levels.
Shaw has long been a fan of triode operation, being the purest form of valve circuit. But triodes have a downside: limited power output. After many months of designing and listening, Shaw has produced what is, in essence, the final pre-production prototype of the Icon Audio MB81: a triode monoblock which can deliver 200 watts RMS into even the most demanding of loads.
At 260mm tall, 100mm in diameter and weighing 1kg each, the GU81 is a truly majestic valve. Although the GU81 still in production, Shaw has used ‘new old stock’ valves in the MB81, hand-chosen for their combination of fine resolution, enthralling musicality and immense power. Always keen to break boundaries and set trends, Icon Audio believe the MB81 to be the world’s first ever push-pull GU81 amplifier.
These massive amps are around 50% bigger than the current Icon flagship MB845MkIIm and weigh around 100kg per pair.
While the MB81 was developed as a personal gift for Shaw himself, he plans to produce a limited number for sale, with an estimated price of £12,500 per pair.
The MB81 will be demonstrated at this week’s National Audio Show at Whittlebury Hall. Visitors will be the first to witness the life-like scale of the stunning new prototypes from Leicester-based Icon Audio.
- Pure Class A triode front end.
- Triode GU81 push-pull output stage.
- The four GU81s can be user-calibrated using Icon Audio’s built-in ‘Easy Bias’ meter.
- All hand wired with silver plated pure copper PTFE audio cable to optimise sound and reliability.
- Low distortion quaternary wound output transformers, potted to reduce noise.