SP – Synthasystem Current Requirements

Nyle published power requirements for his modules SynthaSystem Moduler Power Requirements. I also measured the power requirements using an Extech 570 digital multimeter. I disconnected the LEDs, if there were any, on the power regulation PCBs. If you use these LEDs so you can adjust the regulators before connecting it to the module’s PCB, you need to add about 10mA to each supply that has an LED. I tried to make sure each module was operating at its maximum draw, but some modules, like the keyboard or trigger converter, have a different draw depending on how many keys or trigger inputs are being used. The current for the voltage to S-Trigger converter is taken from the voltage trigger input signal, so technically there is no power taken from the supply connected to the trigger converter to convert voltage to S-Triggers.

The first column is the module, the second is the current I measured, the third in parentheses is what Nyle published. I did three measurements for the VCF. One with discrete 2N5172 transistors, one using the Linear Systems monolithic matched pair – LS318, and one using the monolithic matched pair, SSM2222.

All measurements in mili-amps.

MODULE                                    POS/NEG         (STEINER POS/NEG)

1. VCO-A                                   42/17                     (37/21)
2. VCO-B sq/saw                       26/4                        (26/7)
3. VCO-B sin/tri                          26/4                       (26/7)
4. Dual Voltage Follower            4/4                        (20/20)
5. Input Amplifier                        2/2                          (4/4)
6. VCF 5172                             11/8                         (10/8)
7. VCF 318                              11/16                        (10/8)
8. VCF 2222                             11/8                         (10/8)
9. Voltage Sequencer               68/7                         (60/5)
10. Frequency Divider                87/0                        (100/0)
11. Duophonic Keyboard           80/33**                   (47.5/18)
12. Selective Inverter                 16/15
13. VC Trigger Generator             8/3                         (11/0)
14. Peak Selector                       15/2                         (20/20)
15. Trigger Converter                 11/0***
16. ENVVD                                 18/0
17. VCA                                       7/5                        (7.5/4.5)
18. Triple EG                              32/0                         (70/0)
19. Voltage Processor/Mixer       5/5                         (20/20)
20. Phaser                                 12/11                       (22/25)
21. Ring Modulator                    13/14                       (22/25)
22. Noise Generator                   11/0                         (16/0)
23. Sample & Hold                     28/23                      (35/27)
24. Dual Voltage Follower           4/4                         (20/20)
25. Tuner Monitor                        4/3                          (17/4)

** Each key down adds 5 mA to the keyboard module due to the reed relays
*** Each active S-Trigger to Voltage conversion adds approximately 1.2 mA to the baseline current.