281D
About the 281D PCB
281D is an open source PCB design by DunningtonAudio, published on GitHub under the GPL-3.0 license. It is a 4-layer board measuring 104 × 158 mm, with 370 components from 47 distinct parts.
Other key parts include the L78L10, TL072, TL074, 4001 and 4066. By type, the board carries 206 resistors, 46 capacitors, 37 diodes, 22 connectors, 16 ICs and 13 transistors.
From the project
A quad function generator project
The 281D Quad Function Generator is designed to replicate the functionality of the Buchla 281 module using modern construction techniques and readily available parts. It is primarily based on the original circuit designed by Don Buchla, with the following additions/alterations:
Improved input and mode selection circuitry – no requirement to “kick” the generators when selecting self cycle mode. All outputs are buffered, protecting the integrator core and passive end pulse generation from the effects of loading when stacked to multiple inputs. * End pulse outputs are designed to allow stacking…
Main components on the 281D
281D bill of materials (BOM)
370 components, 47 distinct parts.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | L78L10 | SOT-89-3 | U1 |
| 1 | TL072 | SOIC-8_3.9x4.9mm_P1.27mm | U2 |
| 6 | TL074 | SOIC-14_3.9x8.7mm_P1.27mm | U101, U105/205, U201, U301, U305/405, U401 |
| 4 | 4001 | SOIC-14_3.9x8.7mm_P1.27mm | U102, U202, U302, U402 |
| 2 | 4066 | SOIC-14_3.9x8.7mm_P1.27mm | U103/203, U303/403 |
| 2 | LM13700 | SOIC-16_3.9x9.9mm_P1.27mm | U104/204, U304/404 |
| 1 | Mod_Indicator_1-10_150mil | Mod_Indicator_1-10_150mil | M2 |
| 1 | Serial_Box_150mil | Serial_Box_150mil | M3 |
| 5 | MMBT3904 | SOT-23 | Q1, Q103, Q203, Q303, Q403 |
| 4 | DMMT3906W | SOT-363_SC-70-6 | Q101, Q201, Q301, Q401 |
| 4 | MMBFJ201 | SOT-23 | Q102, Q202, Q302, Q402 |
| 4 | 108-0906-001 | Johnson_108-09XX-001 | J101, J201, J301, J401 |
| 8 | 108-0903-001 | Johnson_108-09XX-001 | J102, J103, J202, J203, J302, J303, J402, J403 |
| 4 | 108-0902-001 | Johnson_108-09XX-001 | J104, J204, J304, J404 |
| 6 | 108-0910-001 | Johnson_108-09XX-001 | J105, J106, J205, J305, J306, J405 |
| 4 | 220n | C_Rect_L7.0mm_W2.5mm_P5.00mm | C_101, C_201, C_301, C_401 |
| 5 | SPDT_ON-OFF-ON | M201xSS1x01 | SW1, SW101, SW201, SW301, SW401 |
| 2 | SPDT_ON-ON | M201xSS1x01 | SW102, SW302 |
| 4 | 50k | Potentiometer_Bourns_3314J_Vertical | TR101, TR201, TR301, TR401 |
| 8 | 10kB | RV16AF-41-(L)R1-XXX | VR101, VR102, VR201, VR202, VR301, VR302, VR401, VR402 |
Show 27 more
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 2 | 100kB | RD901F-40-00D | VR203, VR403 |
| 5 | Red_3mm | LED_D3.0mm | D1, D105, D205, D305, D405 |
| 6 | BAT54C | SOT-23 | D101, D107/207, D201, D301, D307/407, D401 |
| 4 | SZMM3Z10VST1G | D_SOD-323 | D102, D202, D302, D402 |
| 18 | BAT54WS | D_SOD-323 | D103, D104, D108, D109, D199, D203, D204, D208 +10 |
| 4 | Yel_3mm | LED_D3.0mm | D106, D206, D306, D406 |
| 3 | 10u | L_0805_2012Metric | L1, L2, L3 |
| 4 | 22u | CP_Elec_5x5.3 | C1, C2, C3, C5 |
| 26 | 100n | C_0805_2012Metric | C4, C6, C7, C8, C111, C112, C113, C114 +18 |
| 4 | 220n | C_2416_6041Metric | C101, C201, C301, C401 |
| 12 | 47n | C_0805_2012Metric | C102, C103, C199, C202, C203, C299, C302, C303 +4 |
| 5 | 6k8 | R_0805_2012Metric | R1, R134, R234, R334, R434 |
| 13 | 22k | R_0805_2012Metric | R2, R128, R133, R140, R228, R233, R240, R328 +5 |
| 22 | 100k | R_0805_2012Metric | R101, R111, R112, R138, R141, R150, R201, R211 +14 |
| 24 | 4k7 | R_0805_2012Metric | R102, R119, R129, R130, R131, R132, R202, R219 +16 |
| 4 | 15k | R_0805_2012Metric | R103, R203, R303, R403 |
| 30 | 47k | R_0805_2012Metric | R104, R108, R109, R113, R114, R121, R125, R149 +22 |
| 20 | 49k9 | R_0805_2012Metric | R105, R107, R115, R117, R135, R205, R207, R215 +12 |
| 6 | 5k6 | R_0805_2012Metric | R106, R148, R206, R306, R348, R406 |
| 18 | 1k | R_0805_2012Metric | R110, R116, R144, R147, R153, R210, R216, R244 +10 |
| 12 | 4M7 | R_0805_2012Metric | R118, R120, R199, R218, R220, R299, R318, R320 +4 |
| 4 | 150k | R_0805_2012Metric | R122, R222, R322, R422 |
| 12 | 680R | R_0805_2012Metric | R123, R124, R127, R223, R224, R227, R323, R324 +4 |
| 18 | 10k | R_0805_2012Metric | R126, R136, R143, R146, R152, R226, R236, R243 +10 |
| 4 | 470k | R_0805_2012Metric | R137, R237, R337, R437 |
| 4 | 1M | R_0805_2012Metric | R139, R239, R339, R439 |
| 10 | 11k | R_0805_2012Metric | R142, R145, R151, R242, R245, R342, R345, R351 +2 |
281D design files
The KiCad project lives in the DunningtonAudio/281D repository on GitHub; these links point at the commit this page was built from.
- Layout281D.kicad_pcb
281D: common questions
How big is the 281D PCB?
The 281D measures 104 × 158 mm, has 4 copper layers and is 1.6 mm thick.
How many components are on the 281D?
370 components, from 47 distinct parts. The full bill of materials is listed on this page.
Where can I download the 281D design files?
From the DunningtonAudio/281D repository on GitHub, which has the KiCad layout; the links under Design files point to each one.
Can I use the 281D design in my own project?
Yes, under the terms of its GPL-3.0 license, which DunningtonAudio chose for the repository.