Schraeg
About the Schraeg PCB
Schraeg is an open source PCB design by barnabywalters, published on GitHub under the CC-BY-SA-4.0 license. It is a 2-layer board measuring 84.5 × 128.5 mm, with 110 components from 36 distinct parts.
Other key parts include the TL074 and V2164. By type, the board carries 49 resistors, 28 capacitors, 6 diodes, 5 ICs and 2 fuses.
It belongs with the audio designs in this gallery.
From the project
An 8HP eurorack multimode filter module based on the Bastl Cinnamon
Schräg is an 8HP multimode filter module for the eurorack format, based off the Bastl Cinnamon.
As of 2021-03-01, at least one person has reported successfully building the current board revision. However, another builder reported a minor issue with the attenuverter circuits which prevents full-range voltage control over resonance (and limits voltage control over FM). This should be fixable only with component substitutions, we’re working on a fix. More information and updates in the corresponding lines thread.
Main components on the Schraeg
Schraeg bill of materials (BOM)
110 components, 36 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 4 | TL074 | SOIC-14_3.9x8.7mm_P1.27mm | U1, U2, U4, U5 |
| 1 | V2164 | SOIC-16_3.9x9.9mm_P1.27mm | U3 |
| 7 | PJ301M-12 | PJ301M-12 | AUDIO_IN1, BP_OUT1, FM_IN1, HP_OUT1, LP_OUT1, RES_CV1, V_OCT_IN1 |
| 2 | 100K 100k | Alpha9mmPot | CUTOFF1, RESONANCE1 |
| 2 | Polyfuse | Fuse_1206_3216Metric_Pad1.42x1.75mm_HandSolder | F1, F2 |
| 3 | 100k | Alpha9mmPot | FM_ATTV1, INPUT_GAIN1, RES_ATTV1 |
| 1 | VAL** | MOUSEBITE1mm | MOUSEBITE1mm |
| 1 | EURO_PWR_2x5 | PinHeader_2x05_P2.54mm_Vertical | PWR_IN1 |
| 1 | 250K | Potentiometer_Bourns_3296W_Vertical | RES_ADJ1 |
| 1 | 100k | Potentiometer_Bourns_3296W_Vertical | RV_SAW_OCTAVE1 |
| 3 | SW_SPDT | PinHeader_1x03_P2.54mm_Vertical | SW_DRIVE1, SW_RES_DIST1, SW_WOBBLE1 |
| 1 | 5K | Potentiometer_Bourns_3296W_Vertical | V_OCT_SCALE1 |
| 2 | 1N4148 D_Small | D_SOD-123 | D1, D2 |
| 1 | 5V | D_SOD-123 | D3 |
| 2 | LM4040DCK-5 LM4040DBZ-5 | SOT-23_Handsoldering | D4, D6 |
| 1 | MB2S | TO-269AA | D5 |
| 4 | 560PF 560pF | C_0603_1608Metric_Pad1.05x0.95mm_HandSolder | C1, C7, C8, C12 |
| 4 | 10UF 10uF | CP_Elec_5x4.5 | C2, C4, C5, C6 |
| 2 | 100PF 100pF | C_0603_1608Metric_Pad1.05x0.95mm_HandSolder | C3, C9 |
| 3 | 220PF 220pF | C_0603_1608Metric_Pad1.05x0.95mm_HandSolder | C10, C11, C13 |
Show 16 more
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 3 | 220N 220n | C_0603_1608Metric_Pad1.05x0.95mm_HandSolder | C14, C15, C18 |
| 2 | 22UF 22uF | CP_Elec_6.3x5.4 | C16, C17 |
| 10 | 100N 100n | C_0603_1608Metric_Pad1.05x0.95mm_HandSolder | C19, C20, C21, C22, C23, C24, C25, C26 +2 |
| 21 | 100K 100k | R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R1, R2, R3, R4, R5, R6, R7, R8 +13 |
| 2 | 15K | R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R14, R40 |
| 4 | 470R | R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R15, R30, R32, R39 |
| 1 | 22K 22k | R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R18 |
| 2 | 47K 47k | R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R19, R22 |
| 1 | 10K 10k | R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R21 |
| 3 | 1K | R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R23, R24, R25 |
| 1 | 330K | R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R26 |
| 9 | 33K 33k | R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R27, R28, R29, R31, R33, R34, R35, R36 +1 |
| 1 | 1.5K | R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R41 |
| 1 | 470K | R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R43 |
| 2 | 6.8K | R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R44, R47 |
| 1 | 3.3K | R_0603_1608Metric_Pad1.05x0.95mm_HandSolder | R46 |
Schraeg design files
The KiCad project lives in the barnabywalters/Schraeg repository on GitHub; these links point at the commit this page was built from.
Schraeg: common questions
How big is the Schraeg PCB?
The Schraeg measures 84.5 × 128.5 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the Schraeg?
110 components, from 36 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 Schraeg design files?
From the barnabywalters/Schraeg repository on GitHub, which has the KiCad layout and the BOM; the links under Design files point to each one.
Can I use the Schraeg design in my own project?
Yes, under the terms of its CC-BY-SA-4.0 license, which barnabywalters chose for the repository.
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