Roland RC-100

A compact remote controller that Roland built to steer its samplers - and then quietly revised twice in production.

Overview

The RC-100 is a dedicated remote controller that Roland shipped as an accessory for its S-series sampling workstations. The service documentation names it alongside the S-750 and S-770. The overlay sheet, owner's manuals, and disk sets in the parts tables are all annotated "for S-750/S-770," and the accessory block carries the RC-100 overlay as a standard item. So the box was there to give sampler users physical controls instead of forcing every edit through the host machine's front panel.

It's a small box. The service manual lists dimensions of 300 (W) x 173 (D) x 53 (H) mm - roughly 11-13/16 by 6-13/16 by 2-1/16 inches - and a weight of 1.4 kg. It connects to the host over a 5.0 m cord ending in a 9-pin D-SUB connector. That's long enough to put the controller somewhere useful rather than dangling off the back of the rack. The case breaks down into a panel, a bottom chassis, and a base, and the buttons are laid out around a rotary encoder Roland labels the α DIAL.

The button layout shows how the RC-100 was meant to be used. The two-position LED buttons carry legends like REC, PLAY, EDIT:DISK, MIDI, FUNC, UTILITY, MENU, COMMAND, SUB MENU, and EXCUTE (Roland's spelling). The single-position buttons cover numeric entry - 7, 4, 1, 0 on one part number, 8, 9, 5, 6, 2, 3 on another - plus INS, DEL, and the cursor arrows. A separate button row handles START/STOP, up/down, and ENTER, and there's a RESET button on its own part number. This is a menu-navigation and transport surface, not a mixing desk. If you've used an S-750 or S-770, the labels will read as a direct translation of the sampler's own soft-key structure.

Roland revised the RC-100 mid-production, and the service notes document both changes with effective serial numbers. The first concerns the CPU board. At serial SN821100, Roland added two 0.001 µF capacitors at C41 and C42 and increased R23 from 100 Ω to 4.7 kΩ. The stated reason is static - accumulated charge was causing the CPU to hang, and the panel would stop accepting switch input entirely. Roland notes that pressing RESET clears the condition and returns the unit to normal, which is cold comfort mid-session. The second change lands at SN841300. The EP-ROM at IC13 on the CPU board moved from an M5M27C128-2 to a one-time P-ROM, the LH5764-20, and the data line filter shrank from an ESD-R-25D to an ESD-R-19D. Roland flags the two parts as compatible but specifies that service replacements be the new part numbers only - LH5764-20 (PN 15179855) and ESD-R-19D (PN 12449299).

The CPU is an MSM80C31RS, supported by an M60003A-0117SP gate array and a predictable scatter of 74HC logic - NAND gates, hex inverters, a dual 4-bit binary counter, octal D-type latches. The board assemblies carry Roland part numbers 79384110 (control board) and 79384120, sharing PCB 22923512. The miscellaneous parts list also has a ceramic resonator, KMFC1005T1, which is worth knowing when a unit won't boot.

Two things for anyone shopping. First, the RC-100 is not a standalone device. It's a controller for the S-750 and S-770, and it's useless without one. Second, the production revisions mean two units with different serial ranges are not identical inside, and the static-hang issue on early units is a real, documented failure mode rather than a rumor. A later-serial example is the one to hold out for. Period classified listings put an RC-100 ROM card at £150 in the pages of Sound-on-Sound (August 2001, p.283). That's a ROM card, not the controller itself, so keep the distinction in mind when searching.