Hello Paul,

The dual regulation mod is the next level of power supply upgrade for the SL1200/1210 after the installation of the SR5. It is an internal modification of the SL1200/1210 printed circuit board and installation of two additional voltage regulators. It consists of separating the power feed to the control circuitry and the motor drive circuitry and providing each with a separate high performance voltage regulator.

Separating the regulation for the control circuitry and the motor drive circuitry reduces interaction between these stages, via the power line on the internal printed circuit board, and this also improves the sound quality of the deck giving a more open and stable sound stage with improved dynamic scale.

The external SR5 power supply is then adjusted to 27 volts to provide pre-regulation of the two internal regulators, effectively providing two layers of supply line interference rejection and making the deck much less susceptible to performance variations caused by varying mains quality.

Aside from the above improvements there is also a nice improvement in low-level information retrieval with these modifications.

This level of power supply upgrade requires reasonable DIY experience, as some printed circuit track surgery is required as well as wiring in the two additional voltage regulators. For those who do not wish to implement this modification themselves I will be offering this upgrade as a service in the New Year once the holidays are over.

Regards
Paul