# Pentaholic Synth — Polyphonic Sketchpad Synth > Digital recreation of the Gleeman Pentaphonic sketchpad synthesizer. (iPhone/iPad app by Andrew Strickland.) - Source: https://appshunter.io/ios/app/pentaholic-synth/id6762106586 (this page in markdown: same URL + `.md`) - Developer: [Andrew Strickland](https://appshunter.io/developer/1892938530) - Category: Music, Utilities - Price: Free with in-app purchases - Rating: 3.80/5 from 6 App Store ratings · 7 written reviews indexed - Age rating: 4+ - Requires: iOS 16.0 · 21 MB - Languages: American English - Released: 2026-05-09 - Data updated: 2026-08-01 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/pentaholic-synth/id6762106586/reviews.md ## What is Pentaholic Synth? 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. ## Key features - Authentic 5-voice polyphony - 3 oscillators per voice with 8 waveforms - Component-level circuit modeling - Dual ADSR envelopes - 300-note polyphonic sequencer - Joystick and expression pedal support ## Pricing and in-app purchases Base price: Free. **One-time purchases** | Purchase | Price | Type | | --- | --- | --- | | Full Features | $28.00 | one-time | ## Recent user reviews (7 of 7) All indexed reviews: https://appshunter.io/ios/app/pentaholic-synth/id6762106586/reviews.md ### 5/5 — Blown Away *2026-07-28* This synth has many features other synth apps don’t have. Also, works perfectly in GarageBand as well. No complaints. ### 4/5 — Sounds are quality,but a little difficult to navigate between setting and keyboard *2026-07-05* Any chance you would include a popup keyboard And/Or a thumb pad linked directly via midi or such?...the sound is amazing but the zoom feature is functional but slow and debilitating as an onscreen tool in my opinion.Still,an AWESOME Synthesizer ### 2/5 — ok sound 🤷‍♂️ *2026-06-09* but there’s nothing sound wise that makes me want to fork out full price in light of already many purchased synths, the ipad interface is poor & wasting screen space, the way the synth appears on screen (fancy dark light 3d head on angle) is ok for a synth korn magazine but not for finger use (everything tiny, bit like korg module which is also unusable) i cant select presets or knobs properly & the keyboard is muck. the pro jargon about its benefits & under the hood mechanics whatever they all mean are all very nice but its inaccessible to me. as the devs name sake in bttf would say, “slacker!” 🙃 ### 5/5 — Love this synth *2026-06-08* Been using this on the go for a while and absolutely love it ! Works great and layout is easy to understand ! ### 2/5 — I don’t think so. *2026-05-23* Terrible workflow. Just a bunch of ‘stuff’ poorly arranged. And $28 for an app not smart enough to have note hold. ### 3/5 — Sound is nice but… *2026-05-18* The UI is kind of not user friendly. Maybe it’s not made for iPhone but it works fine so not really sure but the scalability of the knobs for the effects and modulation board doesn’t fit so it has to be scrolled along as you work on the surface face. The keys are large but maybe too large, esp if using an external midi and not on screen keys, then would provide more space for the knobs. Other than that, it sounds okay, and does what it does. **Developer response:** Hey, thanks for the honest feedback. This is my first iOS device release. It was definitely a compromise to include the full performance layout of the synth's parameters, 37 keys, and have the joystick available for pitch bend, modulation, and cutoff. I wasn't going to offer an iPhone version, but I remembered getting my first iPhone and having Nlog MIDI synth and how much it changed the way I approached music. That said, I'd love to listen to your feedback more in depth if you have the time to chat via email or video chat. Drop a line at the provided support email, and I'll be in touch. ### 5/5 — Nice sound :) *2026-05-14* Really nice punchy sharp sound that cuts through the mix. If I buy the added features will these features appear also in the auv3? For example the midi cc mapping will it also work in the auv3? **Developer response:** Thank you! Yes, the full features are unlocked for standalone as well as AUv3. ## Frequently asked questions about Pentaholic Synth ### What is Pentaholic Synth? Pentaholic Synth is a digital recreation of the 1982 Gleeman Pentaphonic synthesizer. It aims to provide an authentic sound design experience with a focus on songwriting inspiration and a streamlined workflow. ### What are the key features of Pentaholic Synth? Pentaholic Synth offers authentic 5-voice polyphony, 3 oscillators per voice with 8 waveforms, component-level circuit modeling, dual ADSR envelopes, a 300-note polyphonic sequencer, and support for joysticks and expression pedals. ### Is Pentaholic Synth free to use? Yes, Pentaholic Synth is available for free. It also offers in-app purchases, though the core functionality is accessible without them. ### What devices does Pentaholic Synth support? Pentaholic Synth is designed for Apple devices, including iPhone, iPad, and iPod. It specifically utilizes native Metal 3D graphics for Apple Silicon devices. ### How often is Pentaholic Synth updated? The latest version of Pentaholic Synth is 1.4.2, which was last updated on June 8, 2026. Updates are released periodically to improve functionality and add features. ### What is the age rating for Pentaholic Synth? Pentaholic Synth has an age rating of 4+, making it suitable for a wide range of users interested in music creation. ### Does Pentaholic Synth have ads? No, Pentaholic Synth does not contain advertisements. Users can enjoy the app without interruptions from ads. ### How does Pentaholic Synth compare to other synthesizers? Pentaholic Synth focuses on recreating a specific vintage hardware unit, offering a unique sound and workflow. Its 'sketchpad' concept aims to prevent producer paralysis by limiting options and encouraging quick idea generation. ## Version history (last 4 releases) ### 1.4.2 — 2026-06-08 Redesigned iPhone UI for user enjoyment and playability, key hold gesture added to keyboard. ### 1.4.1 — 2026-05-18 Offer Codes for In-App Purchases ### 1.4 — 2026-05-15 User interface improvements for Metal graphics performance and easier to read value display when adjusting parameters. ### 1.3 — 2026-05-09 No release notes. --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-01.*