Enclosure not stated · 3 knobs
Maestro RM-1A Ring Modulator
Based on the Maestro RM-1A Ring Modulator
- Category
- Vibrato / Chorus
- Build
- Vero· 31×33· 77 cuts, 33 links
- Layout
- Unverified · no build reported at Dirtbox Layouts yet
- Tags
- Maestro, Modulation, Noise, Ringmod
From the post
A requested circuit but bear in mind that it is rather big, has an onboard charge pump for 15v-15v operation, and has a quite complicated setup due to five multiturn trimmers. I've omitted the (for now) the Osc, Pitch, Carrier and Modulation jacks but might add it later on if is requested but it will be an "offboard wiring extravaganza".
Schematic is avaiable HERE Trimper setup is avaiable HERE
Schematic
This is a board layout, a drawing of where each part goes, and the post may link the schematic it was drawn from. Open the layout at Dirtbox Layouts. No KiCad fragment has been drawn for this circuit yet.
Parts list 47 rows
Report a wrong parseGot parts in a drawer? See what you can build with them.
Check before you build · 4 values the reader of this layout was not sure of
- 3.3K at far left (column 2, rows T-V): first digit hidden under the 22uF can, could be 5.3K; read as 3.3K
- D6 (top right, next to CLR): legend prints 'D5: 1N5817' while D4-D5 are the zeners; taken as D6
- Q1: legend gives only 'N CH- J FET, 2N4360 in original', no part number
- 200pF near IC1: printed clearly, unusual value
| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 11 | ||||
| ×12 | 47K | 47k | read from the layout by eye | |
| ×11 | 10K | 10k | read from the layout by eye | |
| ×9 | 4.7K | 4.7k | read from the layout by eye | |
| ×7 | 3.3K | 3.3k | read from the layout by eye | |
| ×3 | 100K | 100k | read from the layout by eye | |
| ×3 | 1K | 1k | read from the layout by eye | |
| ×2 | 18K | 18k | read from the layout by eye | |
| ×1 | 270K | 270k | read from the layout by eye | |
| ×1 | 2.7M | 2.7M | read from the layout by eye | |
| ×1 | 5.1K | 5.1k | read from the layout by eye | |
| ×1 | ? | ? | LED resistor, value not given; read from the layout by eye | |
| Capacitors 7 | ||||
| ×2 | 15nF | 15n | read from the layout by eye | |
| ×2 | 150nF | 150n | read from the layout by eye | |
| ×1 | 330nF | 330n | read from the layout by eye | |
| ×1 | 200pF | 200p | read from the layout by eye | |
| ×3 | 10uF | 10u | electrolytic; legend: use caps rated min 35v; read from the layout by eye | |
| ×4 | 22uF | 22u | electrolytic; legend: use caps rated min 35v; read from the layout by eye | |
| ×4 | 100uF | 100u | electrolytic; legend: use caps rated min 35v; read from the layout by eye | |
| Diodes 11 | ||||
| D1 | 1N4148 | 1N4148 | read from the layout by eye | |
| D2 | 1N4148 | 1N4148 | read from the layout by eye | |
| D3 | 1N4148 | 1N4148 | read from the layout by eye | |
| D4 | 1N746 | 1N746 / 3V3 | 3.3V Zener; read from the layout by eye | |
| D5 | 1N746 | 1N746 / 3V3 | 3.3V Zener; read from the layout by eye | |
| D6 | 1N5817 | 1N5817 | legend prints D5; read from the layout by eye | |
| D7 | 1N4001 | 1N4001 | read from the layout by eye | |
| D8 | 1N4001 | 1N4001 | read from the layout by eye | |
| D9 | 1N4001 | 1N4001 | read from the layout by eye | |
| D10 | 1N4001 | 1N4001 | read from the layout by eye | |
| D11 | 1N4001 | 1N4001 | read from the layout by eye | |
| Transistors 1 | ||||
| Q1 | N-channel JFET | N-CHANNEL JFET | JFET; legend: N CH- J FET, 2N4360 in original; read from the layout by eye | |
| ICs 7 | ||||
| IC1 | MC1458 | MC1458 | read from the layout by eye | |
| IC2 | MC1458 | MC1458 | read from the layout by eye | |
| IC3 | MC1495 | MC1495 | read from the layout by eye | |
| IC4 | LM741 | LM741 | read from the layout by eye | |
| IC5 | LT1054 | LT1054 | read from the layout by eye | |
| REG1 | 7812 | 7812 | regulator; read from the layout by eye | |
| REG2 | 7912 | 7912 | regulator; read from the layout by eye | |
| Potentiometers 3 | ||||
| Pitch | B150K | B150k | Potentiometer | dual; legend: Try 100kC dual gang; read from the layout by eye |
| Modulation | B50K | B50k | Potentiometer | read from the layout by eye |
| Volume | A50K | A50k | Potentiometer | read from the layout by eye |
| Trimmers 5 | ||||
| OSC | 5K | 5k | read from the layout by eye | |
| OFFSET | 5K | 5k | read from the layout by eye | |
| SQUELCH | 5K | 5k | read from the layout by eye | |
| SIGNAL | 5K | 5k | read from the layout by eye | |
| CARRIER | 5K | 5k | read from the layout by eye | |
| Switches 2 | ||||
| Modulate | DPDT on/on | DPDT ON/ON | read from the layout by eye | |
| Pitch Range | DPDT on/on | DPDT ON/ON | read from the layout by eye | |