SERVICE PARTS
840 series
mono channel
| CHANNEL | FUNCT. | POTENTIOMETER | KNOB | CAP | MISC. |
| MIC/LINE | Break | Jack Break/10600432 | |||
| MIC INPUT | XLR fem/10600235 | n.a. | n.a. | n.a. | |
| MIC/LINE | Toggleswitch/10550421 | n.a. | n.a. | ||
| GAIN | 22KBx2/10300109 | Black/10450193 | Red/10450152 | n.a. | |
| HIGH | 100KA/10300113 | Black/10450193 | Yellow/10450154 | n.a. | |
| FREQUENCY | 100KCx2/10300118 | Black/10450193 | Yellow/10450154 | n.a. | |
| MID | 10KLIN/10300103 | Black/10450193 | Green/10450194 | n.a. | |
| LOW | 100KLIN/10300113 | Black/10450193 | Gray/10450195 | n.a. | |
| EQ on/off | Toggleswitch/10550421 | n.a. | n.a. | n.a. | |
| AUX1 | 10KB/10300104 | Black/10450193 | Black/10450153 | n.a. | |
| AUX2 | 10KB/10300104 | Black/10450193 | Black/10450153 | n.a. | |
| PANPOT | 10KCB/10300106 | Black/10450193 | Black/10450153 | n.a. | |
| PFL | Fisheye/10550175 | n.a. | n.a. | n.a. | |
| FADER | Preh not available | n.a. | n.a. | n.a. | |
| IC's | TL074/10250305 | TL071/10250303 | n.a. | n.a. | |
master section
| MASTER | FUNCT. | POTS/MISC. | KNOB | CAP | MISC. |
| OUTPUTS | Jack Ster/10600433 | ||||
| TALKBACK | 10KB/10300104 | Black/10450193 | Red/10450152 | n.a. | |
| AUX RET | 22KB/10300108 | Black/10450193 | Gray/10450195 | n.a. | |
| AUX SND | 10KB/10300104 | Black/10450193 | Gray/10450195 | n.a. | |
| PHONES | 22KBX2/10300109 | Black/10450193 | Gray/10450195 | n.a. | |
| FADER | PREH / not available | ||||
| SWITCHES | Fisheye/10550175 | n.a. | n.a. | ||
| IC'S | TL071/10250303 | TL072/10250304 | TL074/10250305 | ||
| POWER SUPPLY | UA723/10250313 | 2N3055/10250336 |