Supported Features
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VoiceOver
Pentaholic Synth
Polyphonic Sketchpad Synth
Free · In‑App Purchases
Pentaholic Sketchpad Synth - The First Digital Emulation of the Gleeman Pentaphonic - 5 Voice Polyphony - Analog Modeled CEM 3320 24dB Filter - 300 Note Sequencer - MPE
Pentaholic is the first digital recreation of the Gleeman Pentaphonic. It's audio signal path is traced at the component level and built specifically for Apple Silicon devices utilizing native Metal 3D graphics featuring classic and clear UI.
In 1982, the Gleeman Pentaphonic was released as a "sketchpad synth" with a 300-note polyphonic sequencer boasting 5 voices, 3 digitally controlled oscillators per voice, and 8 waveforms per oscillator, all from an 8-bit microprocessor. After DAC, a trio of CEM chips per voice passes the audio: a 3310 envelope generator, 3320 configured as a 24dB low-pass resonant filter, and a 3360 as dual voltage-controlled amplifiers. Each subsequent stage of audio is summed out to a LM348 op amp, stacking saturation through to output. Add performance controls like expression pedal inputs and a joystick for modulation and pitch bend for a performance powerhouse synth.
Pentaholic brings the circuit to life in the digital realm for the first time ever on any platform.
The concept of a sketchpad synth was the main inspiration for this - getting back to the fundamentals of songwriting and sound design. Pentaholic is meant to inspire ideas faster and prevent Producer Paralysis induced by too many options on the piano roll. Record your idea to the sequencer and play over it - the keyboard takes precedence over the sequencer notes so you can nail down your melody or adjust your groove with the rate and delay of the sequencer.
• Authentic 5-Voice Polyphony: True chorusing detune of OSC 2/3 relative to OSC 1's pitch (not BBD!) - oldest note first voice stealing.
• 3 Oscillators Per Voice: 8 waveforms CMP 1 CMP 2 3% PULSE 12% Pulse SQR SAW TRI SIN per OSC and a HIGH or LOW octave mode.
• One octave of chromatic pitch: transposing progressions or leads just like you put a capo on a guitar.
• Component-Level Modeling: The soul of the synth - a 24dB resonant low-pass filter - self-oscillation, and nonlinear harmonic drive of the legendary CEM 3320 filter chip for a distinct bite with each subsequent gain stage pushing into saturation through a LM348 op amp.
• Dual ADSR Envelopes: Precise, vintage-snappy envelope generators for exacting control over amplifier and filter contours. Subtle noise and quick snap attacks from resistor-capacitor networks the envelopes pass through.
• The Polyphonic Sketchpad Sequencer: A massive 300-note sequencer honoring the original hardware workflow. Recording polyphonic chords in real time and yielding to performance on the keyboard in playback.
• Joystick and expression pedal hookups: +/- 5 step pitch bend, modulation of depth of the LFO destination and cutoff expression all from the joystick even more control with expression pedals.
Pentaholic honors the original but Gotham Paradise recognizes the value and convenience of advances for performance available from soft-synths, MIDI 2.0 and Bluetooth.
• *MIDI Polyphonic Expression - *MIDI Learn - *6 Octave Pitch Change - *Master Volume - *Re-assignable joystick 0 to 5 steps - *Sync'd parameters for glide, sequencer rate/delay, LFO rate - *Game controller performance using scales to the directional pad and ABXY buttons, stick click sequencer recording and playback - Bluetooth MIDI controller Connectivity
*Pentaholic is fully functional from download but the following features are accessible with in-app purchase
*Sequencer Volume
*Keyboard Volume
*Master Volume
*6 Octave Pitch
*Unison
*Sync'd Parameters
*Recall or Automation of parameters when hosted in a DAW such as Logic for iPad or Garageband
*User Preset Saving
*MIDI Learn/MIDI CC Parameter Assignment
*M.P.E.
*Sequencer records and plays back but resets when stopped
*MIDI export of recorded Sequences
*Game Controller Performance Mode
*Reassignable Joystick Pitch bend
Keeping Pentaholic's core functionality free for young and new producers who can't afford the full version is important to Gotham Paradise, purchasing the full featured synth helps pay it forward.
Offer Codes for In-App Purchases
The developer, Andrew Strickland, 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.
The developer indicated that this app supports the following accessibility features. Learn More
Information
- Seller
- Andrew Strickland
- Size
- 21.8 MB
- Category
- Music
- Compatibility
Requires iOS 16.0 or later.
- iPhone
Requires iOS 16.0 or later. - iPad
Requires iPadOS 16.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Full Features $28.00
- Copyright
- © 2026 Gotham Paradise
