dot matrix madness
Active member
What are your favorite modifications to the Promethium/HM-2 ? Please let me know:
Numbering of parts referring to the schematic of the Promethium:
1. bypass D4 and D5 (switch). Instead of Germanium ones I've seen BAT46 in the Aion Gravition
2. remove D1, D2, D3 (1N4148) (switch)
3. replace D2 by 1N4001 (switch)
4. introduce symmetrical clipping by adding another diode in the same direction as D2 (switch)
5. change D6 and D7 (1N4148) to red LEDs (switch)
6. increase C11 (1nF) to 10nF or more
7. split middle and high gyrators (add separate 10kA poti)
8. increase R18 (220k) to 330k
9. increase C2 (47nF) to 1µF
10. reduce C10 (1µF) to 33nF
11. modify center frequencies of the gyrators. See this calculator
Numbering of parts referring to the schematic of the Promethium:
1. bypass D4 and D5 (switch). Instead of Germanium ones I've seen BAT46 in the Aion Gravition
2. remove D1, D2, D3 (1N4148) (switch)
3. replace D2 by 1N4001 (switch)
4. introduce symmetrical clipping by adding another diode in the same direction as D2 (switch)
5. change D6 and D7 (1N4148) to red LEDs (switch)
6. increase C11 (1nF) to 10nF or more
7. split middle and high gyrators (add separate 10kA poti)
8. increase R18 (220k) to 330k
9. increase C2 (47nF) to 1µF
10. reduce C10 (1µF) to 33nF
11. modify center frequencies of the gyrators. See this calculator
