BOM:
Qty | Value | Device | Package | Description | Source 1 | Source 2 |
|---|---|---|---|---|---|---|
| 1 | b100k | Potentiometer | 9MM SNAP-IN | 9mm vertical snap-in pot, Alpha / Panasonic style with 6mm built-in knob. | ||
| 3 | 100k | Resistor | R0805 | Resistor | ||
| 4 | 100n | Capacitor | C0603 | Capacitor | ||
| 1 | 10k | Resistor | R0805 | Resistor | ||
| 1 | 10u | Capacitor | C0805 | Capacitor | ||
| 1 | 1M | Resistor | R0805 | Resistor | ||
| 1 | 1k | Resistor | R0805 | Resistor | ||
| 1 | 1n4148 | Signal Diode | SOD80C | |||
| 2 | 1u | Capacitor | C0805 | Capacitor | ||
| 1 | 4k7 | Resistor | R0805 | Resistor | ||
| 1 | 2n5457 | MMBF5457 | SOT23 | N-Channel RF Amplifier | ||
| 3 | 3.5mm Audio Socket | THONKICONN | 3.5mm socket for Eurorack modular synths | https://www.thonk.co.uk/shop/3-5mm-jacks/ | ||
| 1 | Tile Tail | HW-TILE-POWER-FUTABA-WITHLEADNARROW | TILE-POWER-FUTABA-SMALL | "Futaba J" Tile Tail. | ||
| 2 | M7 | DIODEPOWER | DO214AC | |||
| 2 | OPAMP | IC-TL072SMT | SO08 | OP AMP |
Assembly:
- Clean the PCB with Isopropyl Alcohol.
- Solder the surface-mount components to the PCB.
- The four small unlabelled footprints (0603 size) are 100n bypass capacitors.
- Do not install the 1M resistor or 1U capacitor marked DNI.
- Note that instead of a 1U capacitor a 10U is used instead.
- Pin 1 for the TL072 ICs are marked with the large white dot.
- If using hot-air or an oven to solder the surface-mount components then do this now.
- Inspect all of the soldered components for solder bridges between pins and components, especially around the OpAmps.
- Solder the Tile-Tail power cable. The lead should be inserted on the component side of the PCB and soldered on the side with the jacks.
- Solder the jacks and potentiometers to the front of the PCB.
- Attach the front panel.
Testing
- Inspect PCB for solder bridges between components, loose solder balls, tombstones, etc.
- Before powering the module for the first time ensure there are no power shorts. Check that there is no continuity between the pins on the power cable, and across the opamp bypass capacitors (unlabelled 0603 components).
- Patch an LFO into “IN” and patch “OUT” to an oscillator or oscilloscope. When the “TIME” control is full counter-clockwise the output should follow the input. As the “TIME” control is turned the output should be delayed a corresponding amount. Then patch a square-wave LFO into “ON/OFF” and the output should now only be delayed while the “ON/OFF” signal is around 5V (or “high”).