CVOsc

Connect an Expert Sleepers ES-9, ES-8, or any class-compliant DC-coupled interface to your iOS Device, and visualize up to sixteen simultaneous channels of Control Voltage and audio — no laptop, no patch cables to a computer.

  See your patch

  • Up to 16 simultaneous channels in a paged, responsive grid
  • Three display modes: All (every channel), Selected (just the channels you tag), and Overlay (selected traces superimposed on a single canvas for phase and correlation work)
  • Per-channel range, offset, and time base, in volts for CV and normalized units for audio
  • Auto-trigger on zero crossing for rock-steady waveforms
  • Auto-fit to waveform when you just want the trace centered
  • Independent CV vs Audio mode per channel, with renameable identities ("VCO 1", "LFO Slow", etc.)

  Listen in

  • Built-in live monitor: route any input channel to any physical output of the interface
  • Monitor multiple channels simultaneously, each to its own output
  • Output assignments persist across sessions
  • Hot-plug aware — disconnect and reconnect, and CVOsc rebinds automatically

  Pro features (auto-renewing annual subscriptions)

  • Tuner — pitch detection that works on both CV pitch signals and audio. See note name and cents offset live in the pane.
  • Record & Playback — capture every selected channel to its own WAV file, then play recordings back through the interface. CV recordings are routed only to DC-coupled outputs; the app warns you if you try otherwise. Live monitoring and playback share the same USB pipeline, so you can play recordings while monitoring live channels at the same time.
  • Saved Channel Settings — every channel comes back exactly the way you left it on the next launch.
  • Presets — save and recall whole-rig configurations: channel names, signal types, all scale settings, monitor routings — under a single name.

Each subscription is independent. Restore Purchases in Settings re-entitles anything you've previously bought on this Google account. Cancel anytime; cancellations take effect at the end of the current billing period.

  Hardware requirements

CVOsc requires a class-compliant USB audio interface and a USB-C OTG cable. To visualize CV signals (not just audio), the interface must be DC-coupled. A powered USB hub is recommended for tablets that don't supply enough bus power.

Supported DC Coupled USB Sound Cards

Expert Sleepers
  - ES-9 (14 ch)
  - ES-8 (8 ch)
  - ES-3 (8 ch)
  - ES-40 (8 ch)

  Solid State Logic
  - SSL 2 MKII (2 ch)
  - SSL 2+ MKII (4 ch)
  - SSL 12 (4 ch)
  - SSL 18 (10 ch)
  - SSL ALPHA 8 (8 ch)

  MOTU
  - M2 / M4 / M6 (2 / 4 / 6 ch)
  - UltraLite-mk5 (10 ch), UltraLite AVB (8 ch)
  - 624 (6 ch), 8A (8 ch), 8M (8 ch), 10pre (8 ch), 16A (16 ch), 24Ao (24 ch)
  - 1248 (8 ch), 828 (8 ch), 828es (8 ch), 848 (12 ch)

  RME
  - Fireface UCX II (6 ch)

  Universal Audio
  - Apollo Twin / Twin MkII / Twin X / Twin USB / Twin X USB (4 ch)
  - Apollo x4 (6 ch), x6 (8 ch), x8 (10 ch), x8p (10 ch), x16 (18 ch)

  Native Instruments
  - Komplete Audio 6 MK2 (4 ch)

Non-DC Coupled interfaces still work for audio I/O; they just won't pass the validator's DC-coupling check for CV playback.

EULA: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Privacy: https://cvosc.com/privacy.html