| ARP 1003 DUAL ENVELOPE GENERATOR The ARP 1003 consisted of 2 identical ADSR boards. SCHEMATIC - ADSR Board - UNDER CONSTRUCTION!- (click on image to download full-sized version) |  | 
PARTS LIST - ADSR BOARD - UNDER CONSTRUCTION!
| Resistors | 1/4 watt, 10%, carbon composite | 
| Trim Pots | Linear Taper | 
| Capacitors | 20%, 35 volt, tantalum | 
| Capacitors | 20%, 50 volt, ceramic disc | 
| Capacitors | 20%, 50 volt, polycarbonate | 
| Diodes | |
| 1N4148 | CR1 thru CR9 | 
| Potentiometers | Linear Taper | 
| 10 K | R7, R26 | 
| Transistors | |
| A2803-004-A * | Q1 - Noise Select | 
| TZ81 ** | Q2, Q3, Q5 | 
| 2N5172 | Q4, Q6 | 
| Integrated Circuits | |
| LM301AH | Z1, Z2, Z3 | 
* - an ARP part number, most likely a 2N5172. Not all 2N5172's are good as a noise source, so these would have been tested and selected.
** - TZ-81 alternate part was the 2N5249, also defunct. 2N3904 would be a modern equivalent. Also a 2N3906 would be the modern substitute for the TZ-581 (alternate 2N5367) that ARP used as the PNP complement to the TZ-81.