Hercules II circuit-board is a major improvement to Linn Sondek LP12 turntable without Lingo. The hearts of the Hercules II are two high precision and very low noisy crystal oscillators derived by CMOS technology. The switch on the turntable selects the appropriate oscillator either for 33.33rpm or 45 rpm, frequency counters are further dividing the crystal frequencies down to 50HZ for 33.33 rpm or 67.5Hz for 45rpm, other circuits further synthesize the DC square wave to AC, form a pure sine wave and then amplifying the signal that drives the motor at a constant speed.

Hercules II Speed control Board will drive almost all Linn Sondek LP12 that has already been equipped with Valhalla. For earlier serial number, Hercules will only work with those motor pulley designs for country where the AC mains is 50Hz.

The switch on the LP12 provides a trigger to the electronic to start, to stop or select the appropriate speed. But it does not break any mains connection. Power remains on the circuit board all the time. Though static power consumption is very low, but slight warmth may be felt on the turntable's baseboard. The Hercules II circuitry will have the longest life-expectancy when continuously to the mains. However, if desired it may be disconnected at night, in other word, without impairing reliability.

The LP12 Turntable was designed to be operated with a baseboard, some users advocate the removal of the baseboard as they feel that this modification improves the sound. The fact is Hercules II being constantly live, even when the turntable is static, it may cause a serious risk of harm as the power available on the board can be lethal. Therefore, those users who remove the baseboard may consider they will always remember to exercise care not to touch the board when moving the unit, an unwary partner or child may unknowingly find themselves in grave danger.

Take out the Valhalla board by squeezing the stand-off clips with a pair of long-nose pliers.

Remove the switch assembly. As the picture shows the clips lock up with the top-plate. Suggest users using your fingers to push the clips on one side to make it easier to separate from the top-plate.

Install Hercules II board, snapping it onto the same stand-off clips that held the Valhalla.

Connect the AC mains supply to Hercules II board. Make sure Live from AC mains is connected to Live terminal of terminal block.

Connect the motor to the terminal board according to the colour code printed next to the terminal block.

Push the switch through the top-plate and connect the users friendly flexible PCB socket into pins J1 as with the Hercules II.

The output voltage drive the motor has been adjusted to 85V, please do not attempt to adjust without voltmeter.

1. Check your LP12 is setup properly.
2. Connect the mains supply to the Hercules II board.
3. Select 33.33 rpm. Press the switch once, Red led should turn on, the platter will start spinning in 2-3 seconds.
4. Select 45 rpm. The LP12 must be in off condition. In case while operating in 33.33 rpm, turn it off by press the switch once. Press the switch for 5 seconds, the Red led will be turned on and switch to blue led in 5 second. Then leave your finger from the Switch, platter will start spinning 45 rpm.

　Power source: 220-240VAC +/- 10%

　Power Consumption: 13W

　Frequency : 3.2769 MHz and 4.4268 MHz

　A. Hercules II board

　B. Switch with Flexible PCB

　C. Operating Manual.