Shruti Bot
Shruti box drone with effects
Only for iPhone
$1.99 · Designed for iPhone. Not verified for macOS.
iPhone
Shruti Bot is a shruti box you can actually tune.
Ten reeds, laid out the way a real box is — the low Pa and Sa drone pair, the full middle saptak from Sa to Ni, and the upper Sa. Every reed sits at its just-intonation ratio against the tonic, not the tempered approximation, so the drone locks together the way the instrument is supposed to.
Pull up the bellows and it breathes. At zero no air moves at all and the box is silent; push it up and the drone gets louder and pumps harder, until the breathing turns into an audible tremolo riding on top of the tone. Pressure opens the timbre as well as the volume, so a stroke sounds like air moving rather than a fader going up.
THE REEDS
• Ten stops — Pa and Sa below, Sa Re Ga Ma Pa Dha Ni across the middle, Sa above
• Just intonation throughout — 3/2, 9/8, 5/4, 4/3, 5/3, 15/8 against the tonic
• A tapered tuning peg on every reed, plus or minus 100 cents, turned by hand
• Detune two neighbouring reeds and they beat against each other — real acoustic summing, not an effect
• A mixer fader per reed, independent of the stops, for balancing what's already sounding
THE KEY
• Any tonic across all twelve pitch classes, octaves 1 through 6
• A peg for each key, arranged as a keyboard
• Every pitch class keeps its own microtonal trim, so you can build a tuning that isn't twelve-tone equal temperament and it stays put
• The current note and its offset are always on screen
MOVEMENT
• Two free-running LFOs on every reed — one for tuning, one for level
• They run at their own rates and drift in and out of phase, so the beating keeps reorganising and the drone never quite repeats
• Set them slow and the box simply sounds alive
THE CHAMBER
• A swept resonance that moves like a body cavity rather than a filter sweep
• Stereo chorus, the point where the drone opens out of the centre
• Tape delay with a real moving head — sliding the time bends the pitch the way tape does, and the repeats darken as they recirculate
• Plate-style reverb from a quarter second to six
TWO INSTRUMENTS
Tap the logo. Shruti Bot 2 replaces the reeds with four analogue oscillators — sine, triangle, saw and pulse — with phase shaping on each, from slow comb sweeps to full PWM. Everything else carries straight over: the same tuning, the same reeds switched on, the same effects. Only the sound source changes.
No accounts. No subscriptions. No ads. No network. Nothing leaves your device.
Ratings & Reviews
Shruti Bot is now an Audio Unit.
Load it in AUM, GarageBand, Loopy Pro or any AUv3 host and run the drone alongside everything else you're recording. Play a note and the drone follows the key. Your session saves the whole instrument, not just a preset name.
Nineteen drones built in.
Twelve keys of the Sa-Pa riyaz tuning, ready to practise to. A Ma tuning for Malkauns, Marwa and the other ragas with no Pa, where a Pa drone fights the raga. And four that show what the tuning pegs are really for - komal Re, komal Ga, komal Ni, and a just 5/4 major third against the one your piano gives you.
PLAY mode.
Press a key and the drone speaks with an attack, decay, sustain and release. Turn RELEASE to HOLD and it keeps droning after you let go - the way a shruti box should.
Save over a preset.
Refine a sound and write it back to the preset you started from, instead of leaving a trail of near-identical copies behind you.
The developer, Scott Hsiung, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Scott Hsiung
- Size
- 27.6 MB
- Category
- Music
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Age Rating
4+
- 4+
- Copyright
- © 2026 LA Memorial
