Toyland KB-09

01 / DISCOVER KB-09

Discover KB-09

KB-09 recreates the character of Kevin’s Roland SH-09 in a hands-on software instrument. A main oscillator, sub oscillator, resonant low-pass filter and envelope shape everything from deep bass to singing leads and noise percussion. Its signal path follows the SH-09 circuit design; the digital model reproduces how those stages shape and interact with the sound.

Start with one of 24 factory sounds, then make it your own. AGE changes the instrument’s appearance and calibration, while External Input and its envelope follower let incoming guitar, drums or another synth control the filter. Play in your DAW or use the standalone with a MIDI keyboard.

02 / INSIDE THE SOUND

How we built the sound engine

From a schematic to a playable instrument

We started with the SH-09’s circuit design and the way its controls connect. The main oscillator, divided sub oscillator and external input meet at the mixer; the resonant low-pass filter shapes that mixture, and the VCA controls its level. The envelope and LFO move those stages over time. Preserving those relationships gave KB-09 its starting structure.

Turning that structure into software meant choosing mathematical approximations for the oscillator waveforms, envelope curves, gain stages and filter. We did not simulate every transistor and component. The schematic told us how the stages connect; our equations and their calibration still had to reproduce how those stages respond and interact.

The sound engine processes at four times the host sample rate, with band-limited oscillator edges and filtered downsampling.

Inside the filter

The resonant filter was KB-09's biggest sound-design challenge. At high RESONANCE, the SH-09's filter becomes an oscillator in its own right. Add a steady VCO and sweep the filter slowly, and two sources of energy interact inside the circuit. Recreating that balance meant capturing a singing, stable resonance while retaining the movement and character of the hardware.

Our first approximation

Our earlier filter already had four nonlinear stages and a resonance feedback loop, so it could self-oscillate without a separate oscillator. But it gave all four stages the same saturation scale and used a generic soft limiter in the feedback path. Those choices made a working filter; they did not establish the right balance of internal levels and limiting for the SH-09.

What the oscillator-and-filter test revealed

The difficult case was a steady VCO feeding a self-oscillating filter while the filter swept slowly across the VCO’s harmonics. The model could be pulled too strongly toward the incoming oscillator’s pitch, producing plateaus that sounded like steps. With the VCO turned down, the filter swept smoothly. That distinction pointed us toward the interaction between input drive and resonance, rather than simply a stepped cutoff control. Increasing the processing rate alone did not remove the interaction.

Is anybody actually reading this?

Refining the approximation

We then gave the stages different nonlinear headroom scales, informed by the schematic’s interstage gain relationships. Headroom determines how much signal a stage can handle before its response bends into saturation. We also replaced the generic feedback limiter with a diode-like equation, reflecting the circuit’s resonance-limiting path. The important change was the balance between incoming oscillator energy and the filter’s own oscillation, rather than simply turning the input down or adding a cleaner tone alongside it.

The original Roland service schematic guides the four-stage filter and its resonance routing. KB-09 uses four nonlinear low-pass stages with instantaneous feedback, giving each stage an appropriate amount of internal signal headroom and controlling resonance with a separate nonlinear feedback limiter. The stages and limiter are solved together at each internal processing step. This helps the filter sustain its own tone as the incoming VCO changes, while preserving their interaction. Self-oscillation comes from the filter's feedback loop, with no separate sine generator or automatic volume correction.

Some corrections are explicitly software calibration. For example, the model applies a resonance-dependent pitch correction to compensate for the oscillation-frequency shift introduced by its nonlinear equations. That correction is not an extra component copied from the schematic. Likewise, the chosen headroom and limiter scales are engineering calibration parameters, not measurements of every BA662 and diode in Kevin’s instrument.

How we matched the SH-09 — recordings and waveform comparisons

The crucial test put a steady VCO into a self-oscillating filter while its pitch swept slowly past the VCO’s harmonics. The two signals interacted inside the filter, revealing whether its tone stayed steady, changed level or was pulled toward the incoming oscillator. We compared a collection of SH-09 and KB-09 recordings at different VCO mixer levels, alongside filter-only and oscillator-only recordings, captured at 96 kHz in 32-bit floating point. Listening, waveforms and frequency analysis guided the model toward the hardware’s balance of stable resonance and musical interaction. Matching pitch and relative signal levels made those comparisons more useful than copying slider positions alone.

Listening checks were paired with tests of tuning, ordinary patch levels, stability and processing cost across sample rates. The aim was a faithful, playable instrument: steady where the hardware is steady, expressive where its signals interact, and responsive under the fingers.

What the comparisons can tell us

These comparisons show one resonant setting, not every possible patch. Individual SH-09s vary with calibration and condition, and Kevin's instrument has decades of wear. His recordings provide a real musical reference; they are not assumed to define factory specifications. Natural beating and harmonic interaction remain part of the sound.

This is a circuit-informed approximation, not a component-calibrated recreation of the BA662 stages or their limiting diodes. AGE is a creative condition model, not measured decades of wear. See the original Roland service notes.

The schematic supplied the structure; testing and recordings exposed where our first approximation needed refinement. The result aims to follow the hardware’s behavior more closely without claiming that the software is a literal simulation of every component. KB-09’s optional velocity, aftertouch and tempo-sync controls, along with its creative AGE model, are additions to that foundation. See the model’s current evidence and limits.

Official downloads: open the official KB-09 download page and choose Windows, Mac or Linux. Its download buttons always point to the latest published release. GitHub hosts the ZIPs; the Source code archives on its release page are for building the project, not installing it. No GitHub account is needed to download the public release. The extracted synth and manual work offline.

03 / SETUP

Install & open

Choose your operating system for requirements, installation and first-play instructions.

No DAW is required. Each download includes a standalone app. The synth and manual work offline; internet access is only needed for downloads, update checks, bug reports and external links.

Standalone MIDI receive channel: in AUDIO / MIDI, enable your controller under Active MIDI inputs, then choose All channels (the default) or 1–16 under MIDI receive channel. This applies to every enabled MIDI input and is remembered between launches. MIDI Learn follows the same choice. It does not change sound presets or DAW plug-in routing.

04 / FIRST SOUND

Start playing

05 / CHARACTER

Meet AGE

Choose the condition of your instrument.

CONDITION / AGE lives below the instrument. At 1 / Minty it selects the healthy calibration profile. Turn it up to explore a more played-in instrument, then turn it back whenever you like. AGE is saved with your sound and works in both Authentic and Modern modes.

Click a marked AGE position or drag its cap to select one of five conditions. Each appearance has one name:

Inspired by Kevin's own aged SH-09, AGE changes both the synth's appearance and its circuit behavior.

What changes?

Try this

Save a favorite patch. Hold one note and move AGE slowly from fresh to worn. Compare the subtle sound changes, then explore the filter and envelope with AGE at a setting you like. Inspect the panel at L size, and load your saved patch whenever you want to return to the starting point.

06 / HANDS ON

Learn the panel

Drag sliders vertically; drag a knob vertically or horizontally. Hover or drag to read its value bubble. Most sound controls use a 0–10 display; TUNE displays cents in Authentic mode and semitones in Modern mode. Double-click a continuous control to return to its default. Click or drag the ridged switches, or click their adjacent labels. Focused switches also accept arrow keys, Home and End.

Click the gray POWER button to switch the instrument on or off. It stands tall when OFF and sits lower when ON; the red lamp below the POWER label lights when the synth is on. Switching it off mutes the sound and clears held notes. Play a fresh note after switching it back on.

Authentic & Modern

Authentic keeps the original-style routing and ignores the optional velocity, aftertouch, LFO tempo-sync and input-trim settings. Those controls dim. Modern enables them: velocity controls level, channel aftertouch opens the filter (up to three octaves at full pressure and AFTERTOUCH amount), FREE extends RATE down to one cycle every 20 seconds; SYNC locks RATE to musical grid divisions, and INPUT TRIM adjusts external input by ±24 dB. Return to Modern to use their retained settings.

Modern provides deeper maximum LFO modulation: ±36 semitones for VCO pitch and ±8 octaves for the VCF, compared with Authentic's ±12 semitones and ±5 octaves. These are software design ranges. The bender sensitivities are separate.

The header's ENV and EXT indicators show the synth envelope and external envelope-follower activity, respectively. EXT AUDIO opens a routing reminder in the same dialog style as the other KB-09 windows; choose OK to close.

07 / YOUR SOUNDS

Save your sounds

1. Adjust the panel, including AGE and the Authentic/Modern choice.
2. Click SAVE, choose a location you can find again and give the sound a name. KB-09 writes a .kb09 file.
3. To recall it, click LOAD and select that .kb09 file.

SAVE starts in Documents / Toyland KB-09 Presets, with writable copies of all twenty-four factory patches. Choose another folder whenever you like. LOAD starts in the folder where you most recently saved a patch, even after reopening KB-09. Loading a patch from elsewhere does not change that default.

Closing the standalone: choose Save, Don't Save, or Cancel. Use the arrow keys to switch the highlighted Save / Don't Save / Cancel choice, Enter to choose it, or Esc to cancel. Save lets you name a .kb09 file and opens that saved patch next launch. Don't Save starts the next launch with Calibrated Init. Cancel leaves the app open; canceling the save dialog or a failed save also leaves it open. If the saved startup file is moved or deleted, KB-09 falls back to Calibrated Init. DAW projects continue to restore their own plug-in state.

The loaded filename appears in the preset field. The twenty-four factory presets remain available; selecting one recalls its original settings. Save your edits before choosing another sound. Canceling a file dialog or rejecting an invalid preset leaves the current sound unchanged.

A preset saves the sound parameters, including AGE. It does not save held notes, the current envelope position, power or window placement. Your DAW also saves the patch with its project; external track routing belongs to that DAW project.

08 / SEE THE DETAIL

A sharp, comfortable view

Use KB-09’s size buttons to choose a comfortable view. For blurry or low-resolution output, see Solve a problem.

The panel keeps its original proportions. Different screen shapes can leave dark margins. The maximize/restore button is at the top right. A DAW controls its own plug-in frame and may restrict movement or size requests.

Swipe up to fill the screen: in the standalone, drag KB-09's own top header upward to the top edge of the screen, then release to enter L. With touch, use the same upward drag. Pull the header down to restore the preceding size. This fills the available work area while keeping the panel's proportions; on Windows the taskbar remains accessible. Compatible floating plug-in windows on Windows support the same gesture, but a DAW may control placement. Use S/M/L or the maximize/restore button if the host restricts dragging.

Keep the display at its native resolution and retain the DAW's normal HiDPI support. Labels and drawn details stay sharp at the chosen size; photographic surfaces retain the detail of their source images.

09 / YOUR WORKSPACE

Find your DAW

Choose your DAW to expand its display and setup instructions. These instructions help KB-09 render at its own resolution while you use S/M/L to choose its size. Menu wording and available options vary by DAW version; vendor documentation is linked with each recipe.

10 / BEYOND THE OSCILLATOR

Filter external audio

Envelope filter is the precise term. ENV FOL'R follows the loudness of incoming audio and uses it to move the low-pass cutoff: harder playing opens the filter further. This level-responsive effect is often called auto-wah. It differs from an LFO-driven wah, whose movement follows the modulator rather than your playing.

KB-09's VST3 instrument exposes an External Input auxiliary audio bus. A DAW may call this a sidechain. Here the incoming audio can become part of the sound, passing through the mixer, filter and amplifier.

1. Route an audio source to the instrument's External Input.
2. Choose 12 / External Filter. It lowers the oscillators, raises EXT and uses VCA Hold, so no MIDI note is needed.
3. Adjust CUTOFF FREQ and RESONANCE.
4. Try 13 / External Follower: louder input opens the filter for an envelope-filter effect that responds to the input’s loudness. Adjust the VCF ENV amount and the source level.

For envelope filtering, the follower listens before the EXT mixer slider. Lowering EXT can make the source quieter while its filter modulation remains active. The follower does not trigger ADSR or open the VCA; use Hold for continuous processing. Stereo input is averaged to mono, so opposite-polarity channels can cancel. Output is mono duplicated to stereo.

The same envelope-follower idea appears in the original SH-09 owner's manual (external-instrument examples). KB-09 brings that expressive idea into your software setup. Try short guitar chords or a drum loop, lower CUTOFF, add RESONANCE and raise ENV until each attack opens the filter.

In Ableton Live

1. Place KB-09 on a MIDI track; put the source audio on another track.
2. Expand the plug-in device's Sidechain panel. Enable Sidechain, choose the source under Audio From and select the intended tap, such as Post FX.
3. Set the sidechain mix to 100% for a known starting point, then choose External Filter in KB-09.
4. Monitor the processed path clearly. Prevent the source's direct output from masking the filtered result.
5. Save the Live Set to retain the track routing, then reopen it and verify the source and patch.

See the Live 12 sidechain routing guide. Menu names may vary in later versions. In another DAW, use its auxiliary-input or sidechain routing to send audio into KB-09's External Input.

11 / MAKE IT YOUR OWN

Take a test drive

Try these ideas as you get to know the instrument. Tick them as you go, and print the guide if you want to keep your notes. The browser's checkboxes reset when you reload.

Modern TUNE range

In MODERN mode, TUNE spans one octave down to one octave up (−12 to +12 semitones). Double-click for concert pitch at center. AUTHENTIC keeps the original ±65-cent fine-tuning range. Your DAW may display the stored tuning value rather than semitones; the knob’s value bubble shows the effective pitch change.

Play VCO MOD from your mod wheel

Your controller’s modulation wheel (MIDI CC1) controls the VCO MOD fader in both AUTHENTIC and MODERN modes. The fader follows the wheel, changing the amount of LFO pitch modulation; RATE and the selected LFO waveform determine the movement. Each mode keeps its existing depth range.

In a VST3 host, the wheel controls VCO MOD on its next movement, including after loading a sound or changing the fader. Mouse edits and host automation remain available; the next wheel message takes control again. The standalone uses pickup to prevent jumps: move the wheel to or through the fader’s position after a manual edit or preset change. The resulting fader setting is saved with the patch. Record wheel gestures as MIDI CC1, or use the VCO Modulation parameter for DAW automation. In a DAW, other MIDI knobs and faders use the host’s mapping system. The standalone offers MIDI MAP for custom assignments; assigning CC1 elsewhere replaces its normal VCO MOD function until that assignment is cleared.

Map your controller in standalone

Click MIDI MAP, select a highlighted KB-09 control, tap a physical button or move a knob/fader, then click DONE. For a momentary button, release it before DONE; a toggle button needs only one press. When assigning a knob/fader to a switch, move through its middle so KB-09 recognizes direct positioning.

Buttons assigned to controls with three or more positions cycle one position per press. Knobs and faders select positions directly. Continuous controls use pickup: cross the onscreen position to take control without a jump. OPTIONS provides a correction for unusual button behavior.

CLEAR SELECTED removes one assignment; CLEAR ALL asks for confirmation before resetting them all. Mappings remember the MIDI channel and are saved between launches, separately from sound presets. They support absolute CC 0–119 on channels 1–16; set relative encoders to absolute mode. Pitch bend, notes and channel aftertouch keep their normal functions.

Enable DESCRIPTION for hover help. In a DAW, use the host’s mapping system; MIDI MAP is available only in standalone.

Pitch-bender readout

Hover over or drag the spring-return bender to see its signed position, from -100% to +100%; center is 0%. The VCO and VCF depth faders determine the resulting pitch and filter movement, so the position is not a fixed semitone amount. Release the onscreen bender for a short, 35 ms return in AUTHENTIC mode at constant speed without easing. The pointer then makes one small visual recoil over 20 ms before resting at center; the sound reaches neutral at 35 ms without overshooting. MODERN returns immediately, retaining click-free audio smoothing. The spring duration is a playing approximation, not a measured SH-09 calibration. An external MIDI wheel moves the GUI bender and follows the controller’s own return messages. In a DAW, record or edit MIDI Pitch Bend envelopes; the bender position is a MIDI performance control, while its VCO and VCF depth faders are automatable plug-in parameters.

A little more control, a lot more playing

Hold SHIFT while dragging any knob, fader or the bender for ten-times finer adjustment. Release SHIFT to return to normal speed, even during a drag. AGE selects five marked conditions while dragging. Five cached appearances keep movement responsive; full visual detail returns on release. During automation, control positions and key feedback may stay at the last complete preview while you drag AGE; they return live on release. The four utility sliders have larger handles and grab areas. Faders move relative to where you grab them, so a fine adjustment will not jump to the pointer. The DESCRIPTION button in the bottom strip enables hover descriptions; it starts off and lights amber with DESCRIPTION ON when enabled. Hover over DESCRIPTION itself for help even when it is off. Value readouts work with DESCRIPTION off or on. Switches show their selected mode in a readable value box when hovered or adjusted; the box disappears after you leave or finish the adjustment.

VOLUME has an audio taper: quiet levels occupy useful knob travel, 0 mutes, and 10 is full output.

In Modern, choose FREE for the continuous 0.05–25 Hz LFO, or SYNC to follow the host tempo. RATE then selects 21 divisions, from four bars to 1/64-note triplets. Its value box displays the division. D means dotted (one-and-a-half times the straight duration); T means triplet (two-thirds). Bar labels assume 4/4; divisions are quarter-note beat durations and do not change with the host time signature. Without host tempo information the clock uses 120 BPM. Authentic always uses the original free rate, even with a saved SYNC setting.

The RATE lamp follows the LFO clock with clear half-cycle flashes below 8 Hz. At 8 Hz and above it becomes a steady glow that brightens with rate: this avoids misleading flicker when a screen cannot show each cycle. Modulation and LFO envelope triggering continue at the actual selected rate. SYNC follows tempo, not the host transport's bar position; stopping playback does not reset its phase.

The header's IN meter shows audio reaching the plug-in before the AUDIO MIXER's EXT fader and before stereo is folded to mono. ENV shows the synth envelope; EXT shows the external envelope follower. MIDI flashes when notes, pitch bend or other MIDI channel messages arrive. Enable DESCRIPTION and hover over an indicator for an explanation. IN activity with silence at the output means you should check EXT level, VCA mode and filter cutoff. Opposite-polarity stereo channels can light IN yet cancel in the mono signal.

Updating KB-09

Get the latest version from the official download page. Choose your operating system, then follow the steps below. You can also check for updates from inside KB-09.

Click TOYLAND / KB-09 in the top left to open the version and update menu. KB-09 asks whether you want automatic checks when its window opens, at least 90 days after the last successful automatic check. Manual checks do not postpone that schedule. If you are current, the message says You're up to date!

When an update is available, the prompt includes a short What’s new summary when release highlights are supplied. Choose Show update instructions or Not now. Updates are optional. Installation is manual and usually takes a few minutes, depending on download speed. The instructions offer Open downloads and Copy instructions; both leave the instructions open. Copy them before closing KB-09. No update downloads or installs itself.

The official download page always offers the latest release for each operating system. GitHub Releases hosts the files and release notes. No GitHub account is needed to download. If an older KB-09 version sends you to Google Drive, use the official download page to update manually.

Your saved presets and audio/MIDI preferences are kept. Save your current patch before closing KB-09. The normal preset folder is Documents/Toyland KB-09 Presets. Keep personal presets stored inside an old extracted download folder before replacing it.

1. Download the ZIP for Windows, Mac or Linux and extract the entire ZIP.
2. Save your patch and close KB-09. If using plug-ins, also close your DAW.
3. For a portable standalone, replace the old extracted folder, keeping personal presets, and open the new standalone copy. For an installed copy, run INSTALL KB-09.cmd (Windows) or INSTALL KB-09.command (Mac). Both offer an optional desktop shortcut. On Mac the standalone installs in your home Applications folder; AU/VST3 installation is optional and requires your Mac login password.
4. Use the new copy or installed shortcut thereafter. Confirm the new version under TOYLAND / KB-09. Reopen your DAW and rescan plug-ins if necessary.

Update-check preferences belong to your operating-system user account, apply across projects, and are not stored in presets. Failed automatic checks stay quiet. A failed manual check shows a retry message.

12 / QUICK FIXES

Solve a problem

In the standalone app, Ctrl+W (Windows / Linux) or Cmd+W (Mac) closes the window through the same Save / Don’t Save / Cancel prompt as the close button.

13 / FEEDBACK

Report a bug

Found a problem with KB-09 or this manual? Search GitHub Issues for an existing report, then open a bug report if needed. Posting requires a free GitHub account and an internet connection.

Include your KB-09 version, operating system, DAW and version (or Standalone), audio driver and device, and the exact steps, expected result and actual result. For Linux display problems, include the distribution, desktop and X11/Wayland session. Attach a screenshot or a short example if it helps.

Issues and attachments are public. Hide private information in screenshots and do not post passwords, license keys or private music sessions. Nothing is collected or sent automatically. If you are offline, save your notes and post them later.

Made a cool sound? Send me your presets! Share a preset and it might become a factory preset in the next update! Save the .kb09 file, put it in a ZIP and attach it to your submission. Tell me about the sound and how you would like to be credited. Submissions are public and require a free GitHub account.

PROJECT NOTES

About this project

KB-09 is an unofficial personal recreation of Kevin's Roland SH-09, using a circuit-informed digital model and artwork modeled after his own aged instrument. “Authentic” names the original-style routing mode; individual hardware instruments can differ. This project is not affiliated with Roland Corporation and is not for sale.

Free for everyone, forever. Make music, share it with your friends, and enjoy! You may use it to make and sell music, modify it, and share copies for free. Selling KB-09 or modified versions, charging for access, or including it as a paid software component is not permitted under the project license. Third-party components retain their own licenses. See Support/Licenses/KB-09-LICENSE.md in your download for the full terms.

The instrument has one voice, no onboard effects and no sequencer. The standalone includes MIDI mapping; plug-in mapping uses your DAW’s controls. It reports 128 samples of processing latency. Hardware Gate/CV sockets, alternate tunings and per-note expressive protocols are not provided. Use your DAW for recording, effects and arrangement.

Open User Manual.html in the main download folder. Use its Print / Save PDF button whenever you want a printable copy. Vendor documentation links need an internet connection.