The key to building a truly magical amplifier is to maximise the dynamics in the signal and minimise any corruption in the process of amplification. Graham's designs are very concise, using the shortest possible signal path. The Discovery, rated conservatively at 8 watts, is constructed with three carefully divided partitions to eliminate the disruptive effect of magnetic, mechanical and electrical fields for the critical aspects of the circuit. The amplifier is built around the famous 300B valve, that has only three resistors in the circuit and not one capacitor in the signal path. Graham has long been a fan of the 300B valve like many others, but wanted to try to resolve some of it’s apparent weaknesses.
Graham described the development of the amplifier as one of discovery. “There has always been a magical and beautiful richness to the tonal textures possible in the middle frequencies with the 300B valve, however I wanted to discover how to get it to stretch itself in the lower and upper frequencies with the same magic. I would describe the 300B as a little lazy, if you push it too hard it complains, and if you don’t challenge it then it is happy to relax. I honestly feel like I now have discovered the real personality within the valve and the circuit I developed entices a performance from this valve that is truly unique and captivating”
The choice of individual components was also a challenge to ensure the circuit stayed alive and dynamic without smothering the delicate agility of the valve to uncover rich tonal texture. All the components are hard wired and of the highest quality available as well as being oriented to limit interference. Most are specially made to order like the strip wound C core transformers and chokes that are all hand wound. The amplifier takes over 200 hours to carefully assemble, and Graham enjoys the meticulous and intricate work that allows him to focus in an almost Zen like manner. The real pleasure from the build is however the first time that the circuit is switched on, watching those valves wake up and prepare to sing, as you place a favourite LP on the turntable; musical bliss.