Assembly Guide
SMT Components
If manually placing SMT components, use of a stencil and solder paste is recommended.
- D11 and D12
- R33 and R34 (ferrite beads)
- remaining SMT diodes D1-D9 (D3 does not exist)
- Q8 (2N7002K NMOSFET)
- remaining BJTs (Q1-Q7, Q9)
- ICs U1-U4
- Tantalum capacitors C2 and C8
- Ceramic capacitors C3, C1, C4-C7, C9-C14, C17
- Resistors R1-R32
THT Components
Once all SMT components are placed, solder THT components
Front Side
- C15 and C16
- SW1 (push button)
- J1-J3
- RV1-RV5 (note values and taper)
- SW2
Place and solder the 3mm LED once the faceplate is fitted.
Back Side
- J4 (IDC header)
Test and Calibration
No calibration required. To test,
- connect the envelope output to an oscilloscope (use 'roll' mode to capture at 500ms/div+)
- use the manual gate to trigger an envelope (adjust controls, observe response)
- switch to loop mode and confirm repeated envelopes
- apply an additional gate input to the trigger input to check that the AD/R can be triggered independently.
The screenshot below shows the ADSR EG in loop mode with an extra trigger pulse applied during the envelope sequence.

BOM
| Reference | Value | Footprint | Qty |
|---|---|---|---|
| C1,C4,C5,C6,C7 | 10n | 0805 | 5 |
| C2,C8 | 4u7 | 3216-18 Tantalum | 2 |
| C3 | 1n | 0805 | 1 |
| C9,C10,C11,C12,C13,C14,C17 | 100n | 0805 | 7 |
| C15,C16 | 10u | Radial D5.0mm P2.50mm | 2 |
| D1,D2,D4,D5,D6,D7,D8,D9 | 1N4148 | SOD-123 | 8 |
| D10 | LED | LED D3.0mm | 1 |
| D11,D12 | B140-E3 | SMA | 2 |
| J1,J2,J3 | 3.5mm TS Jack | WQP-PJ301M-12 | 3 |
| J4 | IDC 10P Header | IDC Header 2x05 P2.54mm Vertical | 1 |
| Q1,Q2,Q3,Q4,Q5,Q6,Q7,Q9 | BC847 | SOT-23 | 8 |
| Q8 | 2N7002K | SOT-23 | 1 |
| R1,R2,R3,R5 | 100k | 0805 | 4 |
| R4,R7,R8,R9,R17,R20 | 47k | 0805 | 6 |
| R6,R10 | 10k | 0805 | 2 |
| R11,R13,R15,R16,R18,R19,R21 | 22k | 0805 | 7 |
| R12,R14,R33,R34 | 10R | 0805 | 4 |
| R22,R31,R32 | 1k | 0805 | 3 |
| R23 | 270k | 0805 | 1 |
| R24 | 1M | 0805 | 1 |
| R25 | 120k | 0805 | 1 |
| R26,R27 | 4k7 | 0805 | 2 |
| R28,R29,R30 | 100 | 0805 | 3 |
| RV1 | B1M | Bourns PTV09A Vertical | 1 |
| RV2 | B10k | Bourns PTV09A Vertical | 1 |
| RV3,RV4,RV5 | A1M | Bourns PTV09A Vertical | 3 |
| SW1 | Pushbutton | 6mm mom-on | 1 |
| SW2 | DPDT | Dailywell DPDT 2MD1T1B1M1 | 1 |
| U1,U3 | TLC555xD | SOIC-8 3.9x4.9mm | 2 |
| U2 | HEF4093B | SOIC-14 3.9x8.7mm | 1 |
| U4 | TL074 | SOIC-14 3.9x8.7mm | 1 |