Show HN: I made a tiny device for automatically recording digital pianos

Original Article ↗ Hacker News Discussion ↗

A new hardware gadget called Jamcorder automatically records everything played on a digital piano as MIDI, letting musicians bookmark ideas from the keyboard itself and later review, search, and share performances without using a DAW or cloud account. Commenters praise the polished execution, always-on recording, open local APIs, and Bluetooth MIDI features, while raising practical concerns around shipping costs, latency in MIDI passthrough, and long‑term durability of SD storage. Many see it as a capability that should be built into digital instruments by default and suggest extensions such as MIDI playback to the original keyboard, broader support for synths and e‑drums, and future audio‑recording variants.

Overall reception

  • Strongly positive response; many impulsive purchases and gifts for pianists.
  • Praised as a “missing feature” that digital pianos and synths should already have.
  • Design, polish, UX, and “just works” setup repeatedly highlighted.
  • Non-musicians and non-target users still found the concept delightful and well-executed.

Core functionality & technical details

  • Records MIDI only (not audio) to an SD card; supports all MIDI messages, all 16 channels, including pedals, CCs, pitch bend, SysEx.
  • Works with both USB‑MIDI and 5‑pin DIN; acts as MIDI passthrough/thru.
  • Always-on recording with bookmarking via specific key patterns; no need to press “record.”
  • Bluetooth MIDI supported; can replace dedicated Bluetooth MIDI adapters in some setups.
  • Power draw reported around 0.3W.
  • MIDI thru latency was initially variable (5–60 ms), then optimized to ~12 ms constant; acceptable but not zero, and a splitter is suggested for ultra‑low‑latency needs.
  • Local web interface and open Wi‑Fi/BLE APIs; app is optional, recordings readable directly from SD.

Use cases & workflows

  • Main draw: removing friction compared to DAWs, laptops, and complex MIDI routing.
  • Popular for improvisation capture, practice tracking, teaching, and documenting children’s progress.
  • Use with non-piano gear (synths, drum kits, sequencers) discussed and seen as promising.
  • Some want easy MIDI export into DAWs (e.g., Ableton, Reaper); device supports both live Bluetooth MIDI and historical download.

Concerns & criticisms

  • High international shipping costs (especially to parts of EU, NZ, Australia) seen as a major barrier; suggestions for EU/UK distributors and consolidated-shipping services.
  • Some prefer pure audio recorders (Zoom/Tascam) or software-only approaches; question the need for additional hardware and an app.
  • Worries about long-term viability of the app and wireless standards; reassurances point to SD storage and open interfaces but true longevity remains uncertain.
  • Ethically, always-on recording requires informing guests; some debate over adding an “off” switch vs preserving the frictionless design.

Future features & extensions

  • Planned/desired: MIDI playback back into instruments, MIDI loops, customizable bookmarks, richer search/indexing (by chords, motifs, etc.), analytics/tutor features, and broader non-piano support.
  • Separate audio-focused product and/or audio-to-MIDI processing discussed as longer-term directions.