TR-808PSU Rev0.5-110V

TR-808PSU

⚠️ UNTESTED

This board has not been manufactured, assembled or tested. It has not been checked against the real unit, and it has not been tested against any safety standard. The design is a copy of a historical (1984–86) circuit board. It is connected to mains voltage (230 V, or 110 V for the second variant), which can kill. Use at your own risk, and only if you know what you are doing. Dimensions are derived from a scan (±3 %), see VERIFICATION.md.

KiCad rebuild of the power supply board PS3116 (PCB 291-405A) of the Roland TR-808: schematic redrawn from the 1981 service manual, board with outline, holes, terminals and component positions taken from the original component layout. Two variants of the same board:

Both use the same copper; they differ in parts (fuses, transformer, switch, C1) and in the silkscreen mark (PS3116-054 230V / PS3116-051 110V), so the boards cannot be mixed up. Current version: Rev0.5.

Pictures (230 V)

110 V variant

More (230 V; for 110 V use the Rev0.5-110V files, BOM-110V.md): schematic (PDF) · bill of materials (CSV) · 1:1 printout (A4) · Gerber (zip) · assembly drawing (PDF) · original copper vs. tracks · verification · releases

Files

File names with schaltplan, ausdruck, kupfer and leitkarte are German for schematic, printout, copper and guide map.

What "1:1" means here

• Circuit: designators (C1–C16, R1–R7, D1–D4, F1–F4, Q1, Q2, IC1, IC2), values and terminal numbers 1–22 as in the original. The schematic is drawn like the original (mains and switch left, transformer, +5 V branch, ±15 V branch).
• Board: outline (from Rev0.5 with R5 corners instead of the sharp corners of the original), four mounting holes, six heat sink holes (one pair per regulator, 21.3 mm apart, centred) and three M3 screw holes for the regulators, RM5 screw terminals (terminals 1–9), terminal pins (10–22), fuse clips and all components at the positions of the original, fine-tuned to the copper of the scan. The original is single sided with one wire jumper; this rebuild is two-layer.
• Tracks: guided by the original, not copied one to one. The copper of the original is extracted from the scan (halftone → mask → net regions) and used as a cost map by the router: original copper is cheap, everything else is expensive, the component side is almost blocked. The result is a DRC-clean board that follows the original where the scan allows. 37 % of the track length lies on original copper, the rest is routed anew (wide tracks and smoothing move the paths away from the original); psu/TR-808PSU_Rev0.5_ueberlagerung.png shows the original copper (grey) and the tracks (red solder side, blue component side). Pure tracing without the router fails because of the scan quality (shorts between neighbouring tracks, pad positions only within ±0.3 mm).
• Dimensions are derived from the component layout (the manual has no scale), tolerance about ±3 %. Measure against a real board before manufacturing. Details and further open points in ORIGINAL.md.

Status (Rev0.5, 10 Oct 2026; both variants)

• ERC: 0 violations (psu/TR-808PSU_Rev0.5-erc.rpt).
• DRC (clearance rule 0.25 mm): 0 errors; warnings only (4 courtyard overlaps, 1 silkscreen overlap, 7 footprint deviations from the library because of the polarity bars); 0 unconnected items; schematic/board parity 0.
• Mains against low voltage: more than 8 mm copper to copper; between the mains conductors 4.0–5.67 mm, adjacent terminal poles 2.4 mm (RM5 pitch).
• Netlist against the schematic: read by hand from the schematic and checked against the plot; no independent comparison, see "Open" in ORIGINAL.md.
• Track width 1.0 mm throughout; hairpins and stubs in pads are removed; smoothed (45°, arcs). No copper pours, as in the original. Five vias; most of the copper is on the solder side, about 440 mm of track on the component side (the original used the wire jumper J1 for this).
• Silkscreen: designators only (no values), terminal numbers 1–9 next to the screw terminals and P10–P22 on the pins, electrolytic polarity as a bar at the minus side as in the original, the four fuse holders F1–F4 on one line.
• Not done: assembly and measurement on the unit, manufacturing, any safety testing.

Rebuilding

Schematic and layout were generated with a private tool chain that is not part of this repo. The KiCad project in psu/ is complete and needs only KiCad 9/10.

License

Hardware files (KiCad project, Gerber, schematic, documents): CERN-OHL-W-2.0 (CERN Open Hardware Licence v2, weakly reciprocal). The licence covers only this redrawing and layout, not Roland's original design or manual. Provided as is, without warranty: see the disclaimer in the licence and the UNTESTED notice above.

Source and rights

Circuit and dimensions come from the Roland TR-808 service manual (15 June 1981). The manual itself and the data sheets are not part of this repo (copyright of Roland and the manufacturers). This repo contains an own redrawing for repair and rebuild. "Roland" and "TR-808" are trademarks of Roland Corporation; this project is not affiliated with Roland.

Data sheets used to check the pin assignments: 2SB596 (MOSPEC), 2SD880 (DC Components), TA7179P and µA7805 (service manual, page 2).