The Tom Evans Groove & Groove+ Phono Stages
The Groove RIAA stage is the result of over 10 years R&D into disk replay. In developing the Eikos CD player, Tom argued that as long as the voltage regulators supplying the board were noisier than the quietest passages recorded, and their transient response time was slower than the devices were capable of, there was no point in improving the circuit topology until these fundamental problems were solved. Two years later, he had developed the Lithos voltage regulator, a milestone in musical reproduction. The device is 53 times faster, 1000 times quieter, and 5 decimal places more accurate than the previously 'best' regulators available. Thus was laid the foundation for The Groove phono stage.
The case, if made of any metal other than copper, would have a deleterious effect on the sound quality, as field effects of even non-ferrous materials interfere with electron flow. For this reason, the casework is of Perspex, a material with no inductive capacity.
The Groove+ is a Groove with a severely uprated power supply (larger transformer, increased smoothing caps, and an extra layer of Lithos regulation between the standard unit's internal daughter boards and the mains), which makes a substantial difference. The four layers of isolation allow a -180dB noise floor."The power supply makes instruments more solid, but avove all, more natural. It brings the music presence" says Roy Gregory in Hi Fi+. Truly fabulous.