mamut-epm-hw-
orange-dot
Components (31)
| Reference | Value | Description |
|---|---|---|
| Q1 | 2N3904-ish | Reset discharge transistor |
| Q60,Q61 | Q_NPN_BCE | Control side of the thermally-coupled NPN matched pair,Reference side of the thermally-coupled NPN matched pair |
| Q62 | Q_PNP | Sourced output helper driven from the matched-pair control node |
| U1 | LM311 | Voltage comparator, open collector |
| U20 | TL071 | JFET-input op-amp follower that buffers the raw ramp core into `SAW_OUT` |
| C1 | 33p | Small storage cap shapes the reset transistor base drive edge |
| C20 | 10n | Timing capacitor on the raw ramp core |
| C30-C32 | 100n | Light local decoupling from +12V to AGND,Light local decoupling from -12V to AGND,Small filter cap on the reference node |
| D1 | Fast Clamp | Fast clamp diode from base node toward collector node |
| J50 | Bench_In | Bench input header for CV, tune, sync, and analog ground |
| J51 | Bench_Out | Bench output header for saw, pulse, and analog ground |
| R5,R63 | 4k7 | Base drive resistor from RESET_CTRL into the reset transistor pocket,Tail resistor from the matched-pair emitter node into `-12V` |
| R6 | 330 | Series discharge resistor between the ramp node and reset collector |
| R8,R10,R50 | 100k | Base-emitter bleed keeps the reset transistor from storing charge too long,Reference resistor into threshold node,Weak pulldown so SYNC_IN idles quietly when the bench leaves it open |
| R9 | 22 | Small emitter resistor tames the reset sink strength |
| R11 | 330k | Optional sync injection into threshold node |
| R12 | 4M7 | Hysteresis path from reset drive back into threshold node |
| R13 | 2k2 | Open-collector pull-up for reset drive |
| R14,R31 | 1k | Bottom leg of the first low-impedance reference divider,Pulse monitor isolation resistor |
| R20 | 0 | Current-entry link from the expo handoff into the raw ramp core |
| R21,R43 | 10Meg | Light bleed so the summing node has a defined home against AGND,Slow bleed path that keeps the raw ramp node well-defined |
| R22 | 100 | Light output-isolation resistor between the follower and public `SAW_OUT` |
| R30 | 11k | Top leg of the first low-impedance reference divider |
| R40,R64 | 10k | Control resistor from the NPN pair collector into the sourced output helper base,Main CV feed; intentionally dominant in the provisional summer |
| R41 | 220k | Coarse-tune feed; strong enough to move pitch, light enough not to own the node |
| R42 | 1Meg | Fine-tune feed; deliberately gentle around the main pitch path |
| R60 | 2k 3300ppm | PTC tempco element in the real V/oct scale path |
| R61,R62 | 47k | Collector load for the control side of the matched NPN pair,Collector load for the reference side of the matched NPN pair |
| R65 | 220 | Emitter ballast on the sourced expo-current output helper |
| RV60 | 2k SCALE_TRIM | Scale trim divider between tempco-fed `TUNE_SUM` and AGND |
| RV61 | 20k OFFSET_TRIM | Offset trim divider between `REFERENCE` and AGND |