Enclosure not stated · 2 knobs
Oberheim 2 Voice Keyboard
- Category
- Ring Mod / Synth· Full Synths Drum Synths and Misc Synth
- Controls
- Portamento · Pitch Bend
- Price
- see vendor
- Tags
- Full Synths Drum Synths and Misc Synth
Schematic
The schematic is the archived file. Open it at Experimentalists Anonymous, or browse its folder.
Parts list 56 rows
Report a wrong parseGot parts in a drawer? See what you can build with them.
Check before you build · 5 values the reader of this schematic was not sure of
- PNP: notes print '2N8905', read as 2N3905
- keyboard divider: resistor count and value not given
- Pitch Bend series resistor: no value
- 2 Voice Mode: pole count read from the drawing, could be DPST
- A5 offset trimmer: undesignated, perhaps T8
| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 23 | ||||
| ×2 | 5.11K | 5.11k | 1%, PNP current source; read from the schematic by eye | |
| ×5 | 100K | 100k | T2 wiper, A4 output, NPN base, PNP base and -15 V pull-down; read from the schematic by eye | |
| ×1 | 12.1K | 12.1k | 1%; read from the schematic by eye | |
| ×1 | 22K | 22k | read from the schematic by eye | |
| ×7 | 100K | 100k | matched 1% set for transpose; read from the schematic by eye | |
| ×14 | 100K | 100k | 1%: three into A8, four around A6; read from the schematic by eye | |
| ×36 | ? | ? | keyboard divider string, no values drawn; count assumed for 37 keys; read from the schematic by eye | |
| ×1 | 6.19K | 6.19k | 1%; read from the schematic by eye | |
| ×1 | ? | ? | in series with Pitch Bend wiper, value not drawn; read from the schematic by eye | |
| ×1 | 150K | 150k | read from the schematic by eye | |
| ×1 | 470K | 470k | read from the schematic by eye | |
| ×1 | 68K | 68k | read from the schematic by eye | |
| ×3 | 105K | 105k | 1%; read from the schematic by eye | |
| ×1 | 511K | 511k | 1%; read from the schematic by eye | |
| ×1 | 4.7M | 4.7M | read from the schematic by eye | |
| ×1 | 1M | 1M | read from the schematic by eye | |
| ×2 | 180K | 180k | read from the schematic by eye | |
| ×1 | 39K | 39k | read from the schematic by eye | |
| ×2 | 47K | 47k | read from the schematic by eye | |
| ×1 | 4.7K | 4.7k | read from the schematic by eye | |
| ×1 | 220K | 220k | read from the schematic by eye | |
| ×1 | 1K | 1k | read from the schematic by eye | |
| ×1 | 10K | 10k | read from the schematic by eye | |
| Capacitors 5 | ||||
| ×1 | .27uF | 270n | read from the schematic by eye | |
| ×2 | .47uF | 470n | hold caps at A5 and A10; read from the schematic by eye | |
| ×2 | .15uF | 150n | read from the schematic by eye | |
| ×2 | .047uF | 47n | read from the schematic by eye | |
| ×2 | 6.8uF | 6.8u | tantalum, supply; read from the schematic by eye | |
| Diodes 1 | ||||
| ×4 | 1N4148 | 1N4148 | read from the schematic by eye | |
| Transistors 3 | ||||
| ×2 | 2N5172 | 2N5172 | NPN; read from the schematic by eye | |
| ×2 | 2N3905 | 2N3905 | PNP; note reads like 2N8905; read from the schematic by eye | |
| ×2 | 2N4391 | 2N4391 | JFET switches; read from the schematic by eye | |
| ICs 11 | ||||
| A1 | 741 | 741 | read from the schematic by eye | |
| A2 | 741 | 741 | read from the schematic by eye | |
| A3 | 741 | 741 | read from the schematic by eye | |
| A4 | 536 | 536 | FET-input op amp; read from the schematic by eye | |
| A5 | 536 | 536 | read from the schematic by eye | |
| A6 | 741 | 741 | read from the schematic by eye | |
| A7 | 741 | 741 | read from the schematic by eye | |
| A8 | 741 | 741 | read from the schematic by eye | |
| A9 | 741 | 741 | read from the schematic by eye | |
| A10 | 536 | 536 | read from the schematic by eye | |
| A11 | RC4195 | RC4195 | +/-15 V regulator; read from the schematic by eye | |
| Potentiometers 2 | ||||
| Portamento | A1M | A1M | Potentiometer | 1M AUD; read from the schematic by eye |
| Pitch Bend | 50K | 50k | Potentiometer | read from the schematic by eye |
| Trimmers 8 | ||||
| T1 | 1K | 1k | Trans. Adj; read from the schematic by eye | |
| T2 | 10K | 10k | 1 Volt/Oct; read from the schematic by eye | |
| T3 | 10K | 10k | read from the schematic by eye | |
| T4 | 10K | 10k | read from the schematic by eye | |
| T5 | 10K | 10k | read from the schematic by eye | |
| T6 | 10K | 10k | read from the schematic by eye | |
| T7 | 100K | 100k | 2nd voice offset; read from the schematic by eye | |
| ×1 | 10K | 10k | A5 offset null, maybe T8 of the placement drawing; read from the schematic by eye | |
| Switches 3 | ||||
| Transpose | SP4T | SP4T | 2', 4', 8', 16'; read from the schematic by eye | |
| 2 Voice Mode | DPDT | DPDT | read from the schematic by eye | |
| Port Sw | SPST | SPST | off-board via C1/C3; read from the schematic by eye | |