Enclosure not stated · 8 knobs
Forced Fire Pedals Magnus Modulus
Based on the Nathan Alexander Smith (FF_Pedals) Magnus Modulus
- Category
- Delay
- Price
- see vendor
From the vendor
A PT2399 echo designed by Nathan Alexander Smith (FF_Pedals, 2008), adapted from the PT2399 datasheet, the Tonepad Rebote, the BYOC Ping Pong, the Tremulus Lune and the Echo Base. An op amp LFO modulates the delay time for chorus, vibrato and tape-flutter effects and can also drive a JFET for tremolo; the post suggests it as a DIY stand-in for the Roland Space Echo, including self-oscillation.
The three 240k LFO resistors can be 220k instead (shown in red on the drawing). The Rate and Depth pots can be C taper instead of B. The 100 ohm resistor before the Rate pot can be replaced with a B1K pot for a fine rate control.
Schematic
The schematic is in the post. Open it at Revolution Deux. No KiCad fragment has been drawn for this circuit yet.
Parts list 74 rows
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Check before you build · 1 value the reader of this schematic was not sure of
- Values around PT2399 pins 11-14 are small on the drawing; the 0.1u (pins 11-12) and 0.022u assignments are best reads.
| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 29 | ||||
| R1 | 1M | 1M | input pulldown; read from the schematic by eye | |
| R2 | 1M | 1M | input resistor; read from the schematic by eye | |
| R3 | 1M | 1M | input op amp feedback; read from the schematic by eye | |
| R4 | 10K | 10k | dry signal to mixer; read from the schematic by eye | |
| R5 | 10K | 10k | read from the schematic by eye | |
| R6 | 1M | 1M | read from the schematic by eye | |
| R7 | 1M | 1M | read from the schematic by eye | |
| R8 | 1K | 1k | feedback path; read from the schematic by eye | |
| R9 | 12K | 12k | read from the schematic by eye | |
| R10 | 47K | 47k | bias divider; read from the schematic by eye | |
| R11 | 47K | 47k | bias divider; read from the schematic by eye | |
| R12 | 10K | 10k | PT2399 pin 16; read from the schematic by eye | |
| R13 | 10K | 10k | PT2399 pin 15; read from the schematic by eye | |
| R14 | 1K | 1k | PT2399 pin 14; read from the schematic by eye | |
| R15 | 15K | 15k | read from the schematic by eye | |
| R16 | 10K | 10k | PT2399 pin 13; read from the schematic by eye | |
| R17 | 10K | 10k | PT2399 pin 12/11; read from the schematic by eye | |
| R18 | 1K | 1k | Time pot to ground; read from the schematic by eye | |
| R19 | 4.7K | 4.7k | LFO to Time; read from the schematic by eye | |
| R20 | 10K | 10k | mixer input; read from the schematic by eye | |
| R21 | 10K | 10k | mixer; read from the schematic by eye | |
| R22 | 100K | 100k | output pulldown; read from the schematic by eye | |
| R23 | 100K | 100k | JFET gate bias; read from the schematic by eye | |
| R24 | 240K | 240k | or 220K; read from the schematic by eye | |
| R25 | 470K | 470k | read from the schematic by eye | |
| R26 | 240K | 240k | or 220K, LFO feedback; read from the schematic by eye | |
| R27 | 240K | 240k | or 220K; read from the schematic by eye | |
| R28 | 100 | 100 | read from the schematic by eye | |
| R29 | 4.7K | 4.7k | LED resistor; read from the schematic by eye | |
| Capacitors 25 | ||||
| C1 | 100n | 100n | read from the schematic by eye | |
| C3 | 1u | 1u | read from the schematic by eye | |
| C4 | 15n | 15n | read from the schematic by eye | |
| C5 | 1u | 1u | read from the schematic by eye | |
| C6 | 100u | 100u | electrolytic; read from the schematic by eye | |
| C7 | 47u | 47u | electrolytic; read from the schematic by eye | |
| C8 | 47u | 47u | PT2399 pin 2; read from the schematic by eye | |
| C9 | 47u | 47u | PT2399 pin 3/4; read from the schematic by eye | |
| C10 | 2.2n | 2.2n | read from the schematic by eye | |
| C11 | 2.2n | 2.2n | read from the schematic by eye | |
| C12 | 47n | 47n | read from the schematic by eye | |
| C13 | 1u | 1u | delay output coupling; read from the schematic by eye | |
| C14 | 100n | 100n | read from the schematic by eye | |
| C15 | 22n | 22n | read from the schematic by eye | |
| C16 | 100n | 100n | pins 9-10; read from the schematic by eye | |
| C17 | 100n | 100n | pin 7; read from the schematic by eye | |
| C18 | 100n | 100n | pin 8; read from the schematic by eye | |
| C19 | 1u | 1u | read from the schematic by eye | |
| C20 | 470p | 470p | read from the schematic by eye | |
| C21 | 220n | 220n | output; read from the schematic by eye | |
| C22 | 100u | 100u | JFET drain; read from the schematic by eye | |
| C23 | 100u | 100u | LFO to JFET gate; read from the schematic by eye | |
| C24 | 10n | 10n | LFO; read from the schematic by eye | |
| C25 | 100u | 100u | electrolytic; read from the schematic by eye | |
| C26 | 4.7u | 4.7u | LFO to Time; read from the schematic by eye | |
| Diodes 3 | ||||
| D1 | 1N4148 | 1N4148 | or 1N914; read from the schematic by eye | |
| D2 | 1N4148 | 1N4148 | or 1N914; read from the schematic by eye | |
| D3 | 1N400x | 1N400X | reverse polarity; read from the schematic by eye | |
| Transistors 1 | ||||
| Q1 | J201 | J201 | tremolo; read from the schematic by eye | |
| ICs 4 | ||||
| IC1 | NE5532 | NE5532 | read from the schematic by eye | |
| IC2 | PT2399 | PT2399 | read from the schematic by eye | |
| IC3 | NE5532 | NE5532 | LFO; read from the schematic by eye | |
| IC4 | LM7805 | LM7805 | regulator; read from the schematic by eye | |
| Potentiometers 8 | ||||
| Feedback | B100K | B100k | Potentiometer | read from the schematic by eye |
| Delay Level | B100K | B100k | Potentiometer | read from the schematic by eye |
| Time | B50K | B50k | Potentiometer | read from the schematic by eye |
| Gain | B50K | B50k | Potentiometer | read from the schematic by eye |
| Space | B500K | B500k | Potentiometer | read from the schematic by eye |
| Rate | B10K | B10k | Potentiometer | or C taper; read from the schematic by eye |
| Smooth | B500K | B500k | Potentiometer | read from the schematic by eye |
| Depth | B100K | B100k | Potentiometer | or C taper; read from the schematic by eye |
| Switches 3 | ||||
| Delay toggle | SPST | SPST | read from the schematic by eye | |
| Modulation toggle | SPST | SPST | read from the schematic by eye | |
| Tremolo toggle | SPST | SPST | read from the schematic by eye | |
| LEDs 1 | ||||
| LED1 | LED | LED | rate indicator; read from the schematic by eye | |