Ray Wilson authored this content while he was actively running MFOS as the founder and resident genius.
We retain the content because it reflects a valuable point of view representing that time and place.
Article by Ray Wilson
Parts Lists Submitted By Users
BEFORE PURCHASING USING USER SUBMITTED LISTS CHECK THAT THE PARTS LISTED ARE CORRECT.
PLEASE REMEMBER THAT PRICES SHOWN IN ANY LIST WILL INCREASE AS TIME GOES BY.
I DO NOT UPDATE THESE LISTS UNLESS SOMEONE DISCOVERS AND REPORTS AN ERROR.
LIST OF PARTS MOUNTED ON THE FRONT PANEL AND NOT THE PC BOARD
These parts are not mounted on the PC board they are mounted on either the control panel or the input/output panel.Pots: R44, R38, R29, R85, R58, R55, R48, R37, R27, R15,
R11, R10, R92, R90, R19
Switches: S6, S8, S7, S15, S14, S12, S9, S10, S13, S11, S19, S5,
S4,S 2, S3, S1, S18, S16, S17
Resistors: R104, R84, R52, R50, R32, R41, R94, R6, R88, R23
Diodes: D4, D3, D9, D10
Caps: C13, C22
Jacks: Gate In, Osc-2 CV, Osc-1 CV, Output
PLEASE NOTE
Q7 is mounted on the board but as the schematic shows it only needs two holes because you cut the collector off.
| Qty. | Description | Value | Designators |
|---|---|---|---|
| 1 | LF442 or TL072 Dual Op Amp | LF442 | IC2 |
| 3 | LF444 or TLO74 Quad Op Amp(s) | LF444 | IC5, IC6, IC7 |
| 2 | LM13700 or Mouser# 513-NJM#13700D Dual Transconductance Op-Amp | LM13700 | IC3, IC4 |
| 2 | MPF102 (or 2N5457, PN4391, 2N4391) N JFET(s) | MPF102 | Q6, Q5 |
| 1 | CD40106 (74C14) Hex Inverter | CD40106 | IC1 |
| 8 | Silicon Switching Diode(s) | 1N914 or 1N4148 | D7, D1, D2, D3, D4, D5, D9, D10 |
| 1 | 1N5239B Silicon Zener Diode | 9.1Volt Zener | D8 |
| 6 | Transistor NPN(s) | 2N3904 | Q8, Q3, Q1, Q4, Q2, Q7 |
| 4 | Ceramic Capacitor(s) | .001uF | C2, C1, C8, C9 |
| 1 | Ceramic Capacitor | .0047uF | C14 |
| 1 | Ceramic Capacitor | .01uF | C12 |
| 5 | Ceramic Capacitor(s) | .1uF | C10, C11, C19, C20, C15 |
| 2 | Ceramic Capacitor(s) | 100pF | C7, C6 |
| 1 | Ceramic Capacitor (or non-polarized aluminum) | 1uF | C22 |
| 1 | Ceramic Capacitor (or non-polarized aluminum) | 2uF or 2.2uF | C13 |
| 2 | Ceramic Capacitor(s) | 330pF | C21, C17 |
| 2 | Ceramic Capacitor(s) | 560pF | C5, C4 |
| 2 | Electrolytic Capacitor(s) | 100uF | C16, C18 |
| 1 | Tantalum or Aluminum Electrolytic Capacitor | 2uF or 2.2uF | C3 |
| 2 | Linear Taper Potentiometer(s) | 1M | R10, R11 |
| 13 | Linear Taper Potentiometer(s) | 100K | R15, R19, R48, R37, R58, R55, R85, R90, R92, R27, R29, R38, R44 |
| 2 | Multi Turn Trim Pots(s) | 100 ohm | Parts for 1V/Oct Mod |
|
Use metal film 1/4 watt 1% resistors where specified for the least amount of frequency drift.
You may use 1/4 watt 5% resistors in place of 1/4 watt 1% but the oscillators will drift more. | |||
| 8 | Resistor 1/4 Watt 1%(s) | 100K | R68, R69, R74, R54, R57, R63, R62, R73 |
| 2 | Resistor 1/4 Watt 1%(s) | 10K | R64, R65 |
| 4 | Resistor 1/4 Watt 1%(s) | 1M | R67, R66, R59, R56 |
| 2 | Resistor 1/4 Watt 1%(s) | 2K | R60, R61 |
| 2 | Resistor 1/4 Watt 1%(s) | 39K | R50, R52 |
| 2 | Resistor 1/4 Watt 1%(s) | 47K | R76, R75 |
| 2 | Resistor 1/4 Watt 1%(s) | 475 ohms | Parts for 1V/Octave Mod |
| 9 | Resistor 1/4 Watt 5%(s) | 100K | R4, R14, R1, R12, R36, R24, R86, R79, R93 |
| 5 | Resistor 1/4 Watt 5%(s) | 10K | R199, R26, R32, R103, R102 |
| 4 | Resistor 1/4 Watt 5%(s) | 150K | R17, R30, R33, R39 |
| 7 | Resistor 1/4 Watt 5%(s) | 1K | R22, R23, R45, R34, R35, R88, R98 |
| 9 | Resistor 1/4 Watt 5%(s) | 1M | R8, R9, R2, R87, R96, R97, R95, R99, R91 |
| 4 | Resistor 1/4 Watt 5%(s) | 200K | R28, R31, R84, R89 |
| 8 | Resistor 1/4 Watt 5%(s) | 20K | R42, R40, R47, R43, R46, R80, R70, R72 |
| 4 | Resistor 1/4 Watt 5%(s) | 220K | R77, R82, R78, R83 |
| 2 | Resistor 1/4 Watt 5%(s) | 2M | R5, R13 |
| 1 | Resistor 1/4 Watt 5% | 33K | R21 |
| 1 | Resistor 1/4 Watt 5% | 3M | R7 |
| 2 | Resistor 1/4 Watt 5%(s) | 4.7K | R41, R81 |
| 2 | Resistor 1/4 Watt 5%(s) | 4.7M | R3, R100 |
| 4 | Resistor 1/4 Watt 5%(s) | 470K | R18, R16, R20, R71 |
| 3 | Resistor 1/4 Watt 5%(s) | 47K | R49, R104, R101 |
| 2 | Resistor 1/4 Watt 5%(s) | 510 ohms | R6, R94 |
| 1 | Resistor 1/4 Watt 5% | 620K | R25 |
| 1 | DPST Toggle Switch | DPST | S19 |
| 1 | SPDT Toggle Switch (center off) | SPDT | S16 |
| 4 | SPDT Toggle Switch(s) | SPDT | S3, S6, S10, S18 |
| 12 | SPST Toggle Switch(s) | SPST | S2, S4, S5, S7, S8, S14, S12, S11, S9, S15, S13, S17 |
| 1 | SPST Mom. Push Button | SPST | S1 |
| 1 (4 if using optional ext CV ins and Gate) | Phone Jack(s) | 1/4" Jack | J1 (optional: Osc-1 CV, Osc-2 CV, Gate In) |
| 2 | Battery(s) | 9V | B2, B1 |
| 2 | 9V Battery Connectors | 270-325 or 270-324 | Radio Shack Part# 270-325 or 270-324 |
Miscellaneous
Don't go insane trying to find ceramic caps for C22 (1uF) and C13 (2uF).
You can replace C13 with either an axial non-polarized type or two 4.7uF electrolytics placed in series neg. pole to neg. pole. The two positive poles become the leads to the cap which will be about 2.35 uF (which will work fine). The LFO will go a little lower in frequency in "lo range".
You can replace C22 with either an axial non-polarized type or two 2.2uF electrolytics placed in series neg. pole to neg. pole. The two positive poles become the leads to the cap which will be about 1.1 uF (which will work fine).
