Comparison

CVOsc vs HarmonyAngel

Price, ratings, monetisation and update history for both apps, side by side โ€” with what reviewers say about each.

Head to head
About

CVOsc

Features
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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 โ€” no laptop, no patch cables to a computer. See your patch โ€ข Up to 16 simultaneous channels in a paged, responsive grid โ€ข 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) โ€ข Per-channel range, offset, and time base, in volts for CV and normalized units for audio โ€ข Auto-trigger on zero crossing for rock-steady waveforms โ€ข Auto-fit to waveform when you just want the trace centered โ€ข Independent CV vs Audio mode per channel, with renameable identities ("VCO 1", "LFO Slow", etc.) Listen in โ€ข Built-in live monitor: route any input channel to any physical output of the interface โ€ข Monitor multiple channels simultaneously, each to its own output โ€ข Output assignments persist across sessions โ€ข Hot-plug aware โ€” disconnect and reconnect, and CVOsc rebinds automatically Pro features (auto-renewing annual subscriptions) โ€ข Tuner โ€” pitch detection that works on both CV pitch signals and audio. See note name and cents offset live in the pane. โ€ข Record & Playback โ€” 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. โ€ข Saved Channel Settings โ€” every channel comes back exactly the way you left it on the next launch. โ€ข Presets โ€” save and recall whole-rig configurations: channel names, signal types, all scale settings, monitor routings โ€” 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

About

HarmonyAngel

Features
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HarmonyAngel is a MIDI and vocal harmony processor for musicians who want one monophonic line to follow the active chord. Choose chord slots on two performance pages, then play from a MIDI controller or the on-screen piano. For every incoming note, HarmonyAngel can generate descending chord tones below it, align voicings to a chord root, preserve slash-chord roots, and forward aftertouch to the generated harmony. Turn on Mic Input to sing into HarmonyAngel. The app performs low-latency monophonic pitch detection locally, uses the detected note to create the same chord-aware MIDI harmony, and provides a live tuner and input-level meter. Premium users can optionally hear pitch-corrected lead vocal and pitch-shifted vocal harmony audio, with selectable pitch detector, pitch shifter, formant, latency, buffer, trigger-level, and trigger-velocity controls. Choose a Jazz Soli style when you need arranged ensemble-style lines instead of simple chord stacking. Built-in Bebop, Smart Soli, Smooth Big Band, Functional Jazz, Barry Harris, Cool Jazz, Quartal Fusion, Minimal Guide Tones, and Altered Dominant styles use the active chord, melody direction, and musical register to produce practical voicings. Premium users can create, validate, import, export, and organize declarative custom styles in the Jazz Soli Library. Use it standalone with CoreMIDI and the built-in sine synth, or load the AUv3 MIDI processor inside a compatible host. Page controls, progression stepping, hold behavior, custom chord types, selectable MIDI ports, channel routing, keyboard range, display transpose, and velocity shaping are available from the performance UI. Highlights: - Two pages of 12 editable chord slots with no-harmony slots - Built-in chord types, slash roots, and named custom chord types - Jazz Soli styles for melody-aware, multi-part jazz voicings - Premium Jazz Soli Library authoring with validated import and export for custom styles - One-page or two-page MIDI control channel slot switching - Progression controls for stepping through saved chord sequences - Full or partial on-screen piano with touch velocity and aftertouch - Harmony count, root alignment, skip-first-harmony, and revoice-on-switch controls - Delta or ratio harmony velocity and aftertouch shaping - Mic Input with local monophonic vocal pitch detection, tuner, and input-level metering - Premium pitch-corrected lead vocal and pitch-shifted vocal harmony audio - Premium single-channel or rotating-channel harmony MIDI output - Premium MIDI input/output port selection and virtual MIDI output port - Hold and panic controls with process/bypass hold modes - Premium AUv3 MIDI processor extension with preservable host state - Optional built-in sine wave synth for quick testing or standalone use HarmonyAngel is designed for keyboardists, singers, composers, producers, worship musicians, live performers, and anyone who wants fast chord-aware harmony from simple MIDI or vocal input. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://bwinnovationtw.github.io/apps/harmonyangel/privacy.html

Screenshots

CVOsc1 screens
HarmonyAngel4 screens

Verdict

The call

The clearest difference is iOS requirement: HarmonyAngel at 17.0 against CVOsc's 26.4. On price, update cadence, ads and in-app purchases there is nothing between them.

Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS

CostPrice ยท In-app purchases ยท Ads ยท Monetization

Both are free to download. CVOsc sells 4 in-app purchases, starting at $0.99 per year and HarmonyAngel sells 4 in-app purchases, starting at $0.99 per 7 days. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

CVOsc ships an update every 6 weeks, HarmonyAngel every 4 weeks. The most recent releases landed on October 6, 2026 and October 10, 2026 respectively.

Scorecard1 real difference ยท 5 level
CVOsc versus HarmonyAngel: the parameters behind the verdict, then further details
ParameterCVOscHarmonyAngel
PriceFreeFree
Update frequencyEvery 6 weeksEvery 4 weeks โ€” better
AdsNoNo
In-app purchasesYesYes
DevicesiPhone, iPad, Mac โ€” betteriPhone, iPad
Requires iOS26.417.0 โ€” better
Further details โ€” not scored
Size6 MB7 MB
Age rating4+4+
DeveloperAleph Void LLCBetter World Studio

In-app purchases

4 purchases

CVOsc

Subscriptions4
  • CVOsc Annual Tuner$0.991 Year
  • CVOsc Annual Recording$0.991 Year
  • CVOsc Preset Annual$0.991 Year
Show 1 more
  • CVOsc Annual Convert To Gate$0.991 Year
4 purchases

HarmonyAngel

Subscriptions3
  • Weekly Subscription3 Days trial$0.997 Days
  • Monthly Subscription7 Days trial$1.991 Month
  • Yearly Subscription14 Days trial$9.991 Year
One-time1
  • Life-time Purchase$19.99

Questions

Is CVOsc free?
CVOsc is free to download, with in-app purchases available.
Is HarmonyAngel free?
HarmonyAngel is free to download, with in-app purchases available.
Do CVOsc or HarmonyAngel have ads?
Neither CVOsc nor HarmonyAngel shows ads.
Which is updated more often, CVOsc or HarmonyAngel?
CVOsc ships an update every 6 weeks, and HarmonyAngel every 4 weeks. Most recently, CVOsc was updated on October 6, 2026 and HarmonyAngel on October 10, 2026.

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