Just Another LPT DAC
JALPTDAC is a minimalist LPT R-2R DAC that could be assembled within a DSUB-25 connector case. The initial design was inspired by the 1994 COMPUSOUND interface. The latter appears to be an implementation of the MODPLAY PRO Hardware recommendation:
The design is somehow flexible, allowing you to choose from several alternatives:
- Solder a cable to the output and enclose the PCB within a case (like COMPUSOUND)
- Add a 3.5 female plug connector (and use it without the case)
- Implement MODPLAY PRO approach (R = 10K)
- Implement original Covox design (R = 100K)
You can find Kicad files under ./kicad folder, and Gerber files can be found here.
You will need to use high precision resistors (>= 1% tolerance).
component | Value | Mouser ID | Notes |
---|---|---|---|
R0-R8 | 20K - 0.1% | ERA-6AEB203V | |
R9-R16 | 10K - 0.1% | ERA-6AEB103V | |
R17 | N/A | ||
R18 | 0 Ohms | RC0805JR-100RL | (Optional - for dual mono) |
R19 | N/A | ||
C1 | 0.1 µF (Polarized) | T489A104M035ATE20K | |
C2 | 0.01 µF | C0805C103J5RAC7025 | |
J2 | 3.5 Audio Jack | SJ-3524-SMT-TR | (Optional) |
component | Value | Mouser ID | Notes |
---|---|---|---|
R0-R7 | 200K - 0.1% | ERA-6AEB203V | |
R8 | N/A | ||
R9-R15 | 100K - 0.1% | ERA-6AEB103V | |
R16 | 0 Ohms | RC0805JR-100RL | |
R17 | 24K | 6AEB243V | |
R18 | 0 Ohms | RC0805JR-100RL | (Optional - for dual mono) |
R19 | 0 Ohms | RC0805JR-100RL | |
C1 | N/A | ||
C2 | 5100 pF | C0805C512F4HACAUTO | |
J2 | 3.5 Audio Jack | SJ-3524-SMT-TR | (Optional) |
Note: If you decide to use a 3.5 female plug, you can choose between mono and dual-mono output; for dual-mono just short R18 (or add a 0 Ohms resistor)
Wiki section includes some pictures and examples.
Special thanks to: Scali, CallousCoder, & Necroware