Building blocks
About the Building blocks PCB
Building blocks is an open source PCB design by lennartquerter, published on GitHub under the CC-BY-NC-4.0 license. It is a 2-layer board, with 175 components from 101 distinct parts.
Other key parts include the TL074, LM13700, TL072, 4024 and 4001. By type, the board carries 81 resistors, 35 capacitors, 21 ICs, 10 diodes, 4 transistors and 3 switches.
It belongs with the audio designs in this gallery.
From the project
Lenimal Github for DIY for a Eurorack Synth
A coherent set of fully analog drum voices for techno, based on the classic Roland circuits (808 for metals/percussion, 909 for snare/clap). No sampling, no DSP — every voice is an oscillator/noise source shaped by analog filters, envelopes and VCAs.
This README is the index: it explains what goes together, the shared building blocks every voice reuses, and the parts/BOM philosophy for the rebuild. Each module then has its own README with a concept + circuit-block brief.
Main components on the Building blocks
Building blocks bill of materials (BOM)
175 components, 101 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | TL074 | U1 | |
| 1 | LM13700 TL072 | U2 | |
| 1 | TL072 ICM7555xB | SOIC-8_3.9x4.9mm_P1.27mm | U3 |
| 2 | 4024 | U4, U6 | |
| 10 | TL072 | U5, U7, U9, U11, U12, U13, U16, U18 +2 | |
| 1 | 4001 | U8 | |
| 1 | 4046 | U10 | |
| 2 | TL074 | U14, U19 | |
| 2 | LM13700 | U15, U17 | |
| 1 | MMBT3904 | SOT-23_Handsoldering | Q1 |
| 1 | MMBT3906 MMBT3904 | SOT-23_Handsoldering | Q2 |
| 1 | MMBT3906 2N3904 | TO-92_Inline | Q3 |
| 1 | MMBT3904 MMBT3906 | SOT-23 | Q4 |
| 1 | TRIGGER_INPUT | Jack_3.5mm_QingPu_WQP-PJ398SM_Vertical_CircularHoles | J1 |
| 1 | OUTPUT | Jack_3.5mm_QingPu_WQP-PJ398SM_Vertical_CircularHoles | J2 |
| 1 | B100K B1M | Potentiometer_TT_P0915N | RV1 |
| 2 | B100K B10K | Potentiometer_TT_P0915N | RV2, RV9 |
| 1 | B500K B1M | Potentiometer_TT_P0915N | RV3 |
| 1 | B10K B500K | Potentiometer_TT_P0915N | RV4 |
| 1 | B500K B100K | Potentiometer_TT_P0915N | RV6 |
Show 81 more
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | B100K 10K | Potentiometer_Bourns_3296W_Vertical | RV7 |
| 1 | B100K | Potentiometer_TT_P0915N | RV8 |
| 1 | B100K | Potentiometer_TT_P0915N | RV10 |
| 3 | B10K | Potentiometer_TT_P0915N | RV11, RV12, RV14 |
| 2 | 100K | Potentiometer_Bourns_3296W_Vertical | RV15, RV16 |
| 1 | 25K | Potentiometer_Bourns_3296W_Vertical | RV17 |
| 3 | A100K | Potentiometer_TT_P0915N | RV19, RV20, RV21 |
| 1 | A10K | Potentiometer_TT_P0915N | RV22 |
| 1 | EXT_INT | SW_default | SW1 |
| 1 | ON_OFF | SW_default | SW2 |
| 1 | RESET | SW3 | |
| 4 | 1N4148WS | D_SOD-323_HandSoldering | D1, D2, D4, D9 |
| 1 | 1N4148WS LED | LED_D3.0mm | D3 |
| 2 | 1N5819WS 1N4148WS | D_SOD-323_HandSoldering | D5, D6 |
| 2 | 1N4148 1N4148WS | D_SOD-323_HandSoldering | D7, D8 |
| 1 | 1N4148WS | D_SOD-323_HandSoldering | D10 |
| 1 | 1NF 10nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C1 |
| 1 | 470NF 10nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C2 |
| 1 | 2.2UF 2.2uF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C3 |
| 1 | 2.2UF 10nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C4 |
| 1 | 47NF 100nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C5 |
| 1 | 33NF 10nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C6 |
| 1 | 2.2NF 10nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C7 |
| 1 | 10NF 220nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C8 |
| 1 | 22NF 100nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C9 |
| 1 | 47UF 100nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C10 |
| 2 | 100NF 100nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C11, C13 |
| 1 | 100NF 47nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C12 |
| 1 | 47UF 10nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C14 |
| 1 | 100NF 10nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C15 |
| 3 | 100NF 1nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C16, C17, C19 |
| 1 | 100NF 2.2uF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C18 |
| 3 | 10nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C20, C34, C35 |
| 1 | 1nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C21 |
| 1 | 2.2uF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C22 |
| 3 | 100nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C23, C25, C33 |
| 3 | 2.2uF | CP_Elec_5x4.4 | C24, C29, C32 |
| 3 | 4.7nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C26, C27, C28 |
| 2 | 220nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C30, C31 |
| 1 | 330K 100K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R1 |
| 1 | 100K 47K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R2 |
| 1 | 100K 22K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R3 |
| 1 | 100K 200K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R4 |
| 2 | 10K 2K2 | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R5, R15 |
| 2 | 10K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R6, R21 |
| 1 | 68K 4K7 | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R7 |
| 1 | 180K 1M | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R8 |
| 3 | 10K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R9, R54, R63 |
| 3 | 1K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R10, R35, R77 |
| 1 | 1K5 100K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R11 |
| 2 | 10K 100K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R12, R17 |
| 1 | 2K2 1K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R13 |
| 1 | 33K 10K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R14 |
| 1 | 4K7 2K2 | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R16 |
| 1 | 6K8 100K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R18 |
| 1 | 1K5 20K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R19 |
| 1 | 3K3 20K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R20 |
| 3 | 10K 20K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R22, R24, R26 |
| 1 | 1K5 10K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R23 |
| 1 | 100K 10K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R25 |
| 1 | 100K 3K3 | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R27 |
| 1 | 100K 1K8 | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R28 |
| 11 | 100K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R29, R36, R37, R55, R56, R64, R67, R76 +3 |
| 1 | 100K 1M | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R30 |
| 1 | 22K 1M | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R31 |
| 2 | 470K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R32, R44 |
| 2 | 10R 100K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R33, R34 |
| 1 | 120K 100K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R38 |
| 2 | 3K3 | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R40, R46 |
| 3 | 2K2 | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R41, R47, R53 |
| 4 | 1M5 | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R42, R43, R48, R51 |
| 2 | 2M2 | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R45, R50 |
| 6 | 1M | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R49, R52, R58, R59, R70, R74 |
| 1 | 270K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R57 |
| 5 | 47K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R60, R61, R62, R72, R75 |
| 2 | 220R | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R65, R66 |
| 1 | 27K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R68 |
| 1 | 39K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R69 |
| 1 | 330R | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R71 |
| 1 | 18K | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R73 |
| 2 | 1K5 | R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R81, R82 |
Building blocks design files
The KiCad project lives in the lennartquerter/euro-rack-synth repository on GitHub; these links point at the commit this page was built from.
Building blocks: common questions
How big is the Building blocks PCB?
The Building blocks has 2 copper layers and is 1.6 mm thick.
How many components are on the Building blocks?
175 components, from 101 distinct parts, with part numbers taken from the project's own BOM. The full bill of materials is listed on this page.
Where can I download the Building blocks design files?
From the lennartquerter/euro-rack-synth repository on GitHub, which has the KiCad layout, the schematic and the BOM; the links under Design files point to each one.
Can I use the Building blocks design in my own project?
It is published under CC-BY-NC-4.0, which limits how it may be reused; read the license before building on it.
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