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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 Groove is a dual mono design using one Lithos 7 regulator per
side to supply power to each mono signal path p.c.b. The regulators are powered by a dual mmono mains power supply.
Channel separation is therefore limited only by the specifications of the cartridge used. All resistors are Holco precision
metal film. At the front end, Tom has used very
low noise I/Cs (less noise than a 50-Ohm resistor). This stage is followed by a passive RIAA EQ circuit. The third stage is
an ultra linear gain amp; around this he has placed the active lower frequency filter to roll off subsonics. The fourth stage
is the output stage, which is capable of driving several meters of interconnect.
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. Since its launch
in the UK, it has become the industry standard. The Groove can be upgraded to the Plus spec.
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 The mains pcb has been replaced by the Lithos 6, a complex
class A regulator. Its outputs then feed the dual mono Lithos 7s on the signal pcbs. The external mains supply box contains
a 70 watt transformer designed and manufactured in house. The transformer has an electrostatic screen to remove any RF noise,
then rectified, smoothed, and regulated before leaving the box and heading for the Lithos 6. The ultra low noise and distortion
of this product provide audiophiles with the greatest possible dynamic range and resolution available. "The power
supply makes instruments more solid, but above all, more natural. It brings the music presence" says Roy Gregory in Hi
Fi+. Truly fabulous.
The Groove+ SRX makes available the option of user adjustable resistive and
capacitive loading. The circuit board incorporating the banks of dip switches for 9 different resistive and 5 different capacitive
loads is external t the signal path. The SRX also includes new front end circuitry (the SR stands for SUPER RESOLUTION) that
drops noise and distortion by over 50% Roy Gregory says "Swapping from the Groove + to the SRX, the first thing you'll
notice is the dramatic increase in sheer substance and colour...What the SRX upgrades do for the Groove is place it firmly
back at the top table of vinyl replay. It is also, and by some distance, the most affordable of the various options I see
seated there."
Prices:
The Groove $4000
The Groove+ $7600
Groove to Groove+ upgrade: $4400
Groove+ SRX $8,900
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