Sampler

Sampler is a sixteen-pad sampling groovebox in the browser, inspired by the SP-404 — the line of small, rugged boxes that has been the sketchpad of hip-hop and lo-fi production for two decades. Press power on and hit a pad. Ten banks of sixteen pads sit underneath, each pad a sample with its own start, loop and end points, its own envelope, pitch and speed, and its own route into the effects.

The instrument is built around its buses. Every pad sends to BUS 1, to BUS 2, or straight through dry, and each bus carries one of forty-two effects — filters and resonators, tape and cloud delays, vinyl and cassette simulations, a turntable stopper, a back spin, a sideband filter, a vocoder — while two more buses sit across the master output. The three CTRL knobs always edit whichever bus you last touched, and holding the VALUE knob reaches the sub-parameters underneath. The effects are the point: the same four bars through a resonator and a worn cassette is a different record.

Beneath that is a pattern sequencer at 480 ticks to the quarter note. Record in real time over a looping bar and it quantises to whichever grid you pick, with a shuffle that slides the upbeats late; or switch to step recording, where the pads become the sixteen steps of a bar and you place hits one at a time, each with its own velocity and pitch. Patterns chain. Knob moves record into the pattern as automation, and so do pad mutes, so a filter sweep or a dropped-out kick plays back with the part. Hold the D/I and E/J bank buttons together and the pads rearrange into a two-channel DJ mixer — play, cue, pitch bend, tempo sync, and a crossfader on the third knob.

The pads are 1234 / QWER / ASDF / ZXCV. Hold Shift for the second function printed under every pad and button: chromatic play across a scale you choose, sixteen fixed velocities, mute and link groups, tap tempo. Drag or scroll any knob. Drop an audio file onto the page and it lands on the next free pad with its tempo estimated; chop a break at its transients and the pieces spread across the pads to be replayed in any order. Whatever you record stays between visits.

It began, like Gridsong, as an experiment in building from documentation alone. I read the hardware's reference manual with an AI model and asked for a working instrument — no reference implementation, no firmware, no samples, no photographs of the panel. Some of what you see is inferred rather than copied: the manual's MIDI note map is what fixes pad 1 at the top left, and the shortcut appendix is implemented in full and printed on the panel in the places the hardware prints it.

Plain HTML, CSS and JS with Web Audio, no libraries, light or dark to match the page. Most effects are Web Audio node graphs; the ones whose character comes from sample-level work — the looper, the back spin, the crusher, the vinyl and cassette simulations, the varispeed effects, the pitch shifter and the vocoder — run in a custom AudioWorklet. The preload sounds are synthesised at start-up rather than recorded, so the kit is a set of impressions rather than copies. Sampler is an independent project, not affiliated with or endorsed by Roland: it contains no Roland code, firmware, audio or branding, and the effects are recreations built from documented parameters rather than ports.