This is a Simplified Ultrapitch Modification for the Numark PT01
Parts needed:
Resistor between 1k ohm and 2k ohm
notes:
-when the platter speed switch is set the 33rpm, the platter will spin at ~22rpm
-when the platter speed is set to 45rpm, the platter will spin at 33rpm
-this mod can only be done on newer (example 2014) PT01 turntables
-older models, such as circa 2006, have a different motor control circuit and require a different mod
-the new models have the orange potentiometer shown below, where the older models have a blue potentiometer
-download the “RPM – the turntable speed accuracy checker” iPhone app to test platter speed
-this mod came from a forum comment by Rasteri, which said “Replace VR1 with a 2K resistor and that lowers the 33RPM speed to about 20RPM”
-buy Dj Focus’ ultrapitch mod for full control, and to support the skratch community
-works with ultrapitch 7” records, such as skiratcha breaks from DJ A1
-Remove and Replace VR1
1. Unsolder the potentiometer in VR1
2a. Solder a resistor across the 2 pins shown in pic_1_replace_VR1. This picture shows a 2.2k ohm resistor in place of VR1. This results in a platter speed of ~20rpm, when the platter speed switch is set to 33rpm, and ~32rpm when set to 45rpm (varies between turntables).
-Alternate VR1 values
2b. It was found through test that a 960 ohm resistance across VR1 results in a clean 33rpm, when the platter speed switch was set to 45rpm. This resistance results in 22rpm, when the platter speed switch is at 33rpm. A 820 ohm and 150 ohm resistor were connected in series to achieve ~970 ohms. The resulting speed vs. resistance value depends a lot on the friction between the spindle and the platter. A value between 1k and 2k ohm should work great. see pic_2_replace_VR1_series