chiron

If you have got a Citronic PD1, there is a mod you can do to increase
the torque. Open the deck up and search for big resistor R117 on the
motor PCB. Its value is approximately 1.5 Ohms. To increase the
torque, short this resistor out or replace is with a 0.25 Ohm
resistor. This should give you about 10% increase. However you do this
entirely at your own risk, the above advice is theoretical and I
havent yet tested the deck. What you are doing is removing the
protection resistor and potentially passing too much current through
the drive coils which 'could' burn them out. You have been warned.

If I have time to test the mod then I will post back with the results.

chiron

Ok tested it, you get a small increase in torque but nothing major.
The motor drive runs off 24v DC from a 7824 regulator however the
transformer is approx 33v so I will try altering the regulator voltage
to see what happens. I may need to add extra heatsinks to the Sanken
H-bridge driver device to cope with the extra force.