The SIMMONS SDSV 80s Drum Brain

Simmons 80s Drums SDSV

An analog drum synth legend now in V2

You probably already heard a Simmons drum synth without even knowing it... wondering what was used to produce that huge drum sound?

The Simmons hexagonal shaped Electronic drums were all over the place on countless records and live shows during the 80s , used by artists and bands like Genesis, King Crimson, Jean Michel Jarre, Prince, Herbie Hancock, Pink Floyd etc...
The sound was not especially realistic but it got a sound of is own, huge and versatile.
Invented by Dave Simmons, the most famous drum brain was called SDSV or SDS5 , a drum synthesizer, bringing synthesis into the drummer's hands at the same time as defining the sound of a generation.

Often used in a lazy way to generate disco-esque pewww pewww tom sounds, the SDSV module could produced a wide range of sounds. It got great punch and sensitivity.
The SDSV successor called SDS7 added digital lo-fi samples and additional features such as bend direction or FM modulation as means for broader range of possible sounds.

The SDSV is a historical analog gear that has a place in the sound of the 80s and is still used today as secret weapon, drum layering or central part for genre defined music.
Only around 5000 of these drum brains where produced so don't count on finding a working one easily and for cheap.
As there were no accurate VST for this legend out there...

I had to make VSDSX, a perfect recreation with tons of added new features! this is dedicated to Dave Simmons.

VSDSX, which stands for Virtual Simmons Drum System Extended, provides the closest experience to the real thing, for each voice or as it was called (module) it models accurately the analog sound generation, internal circuitry tuning, trigger velocity sensitivity and all the details you can find explained inside the dedicated manual.
For its hybrid voices (HIHAT, CYMBAL, PROM & CLAP are a mix of analog/digital) clocks and counters reading EPROM memory at variable sample rate are perfectly emulated in realtime.
It models the SSM2044 filters offering fine tuning control over internal control voltages, trigger shapes, and VCA response. It also emulates how the module will react if triggered with pads or sequencer...MIDI velocity will change the synthesized sound drastically whether you use real drums trigger detection or piano roll style composition.
Offering multi output capability for your DAW, VSDSX will give you that legendary powerful analog punch! On top of the cake, one voice can load your own external EPROM image data (digital sample) like on a real SDS1 (EPROM based) pad...offering a whole new range of sounds.
VSDSX is now on version 2 and features among other cool things a perfectly emulated Simmons Digital ClapTrap module, a clap synth which combines a variable sample rate digital source combined with pitched analog noise, an original feature of the unit was to never produce the same sound twice. Although it is integrated inside VSDSX a dedicated plugin with stereo widening and chromatic (per note) trigger capabilty is provided as a bonus.

VSDSX provides a huge synthetic drum sound by itself and can also be used with great efficiency in drum layering. Parameters automation and modulation can turn this thing into a crazy an creative sound source

Using it for layering with VPROM can produce a nasty funky sound which combines analog and early digital!

Simmons SDSV Drum brain

Coming as a bonus with your VSDSX 2.0 package, a perfectly recreated ClapTrap plugin with additional stereo capability

Simmons Digital Claptrap

Simmons Claptrap VST plugin

Get VSDSX!


VSDSX VST

VSDSX VST Videos & Sounds Demos Playlists.

The ultimate 80s drum sound!

VSDSX Simmons SDSV Extended VST Features and Details

ANALOG MODELED OSCILLATOR

The special tone character of the drum synth is mainly caused by the raw analog waveform generation and by the circuitry itself, it generates harmonics that are normally not present in an ideal triangle waveform, VSDSX emulates that behavior and also models the analog clipping that occurs when pushed hard. You can also switch to a clean mode which will behave like an ideal system without OPAMP bandwidth limitation (more highs). These features alone offer a great versatility for sound design. A custom mode can switch all oscillators from the typical Simmons shape to a Sine shape that can be used if you would need less harmonics

NOISE GENERATOR CIRCUITRY TWEAKING

The sound source of the drum synth was mainly a mix between a triangle oscillator and a transistor based noise generator. The way it was initially connected could be tuned for more or less frequency content. Each voice has different configuration and VSDSX offers user control over the internal noise filtering (especially useful on the snare voice card).

A lot of the circuitry parameters can also be fine-tuned, CV and VCA response, Trigger types (that will mostly impact the click attack generator time) etc.

SSM2044 Filters

The noise source was filtered by an SSM2044 lowpass filter chip, the filter acts on the noise and click part and behave differently depending on the voice, on bass & toms the resonance resistor was usually set to no resonance, but this can be tweaked inside the VSDSX if you want.

PITCH BENDING & SDS7 LFO FM modulation

One of the obvious things that must be there in a drum synthesizer is a pitch envelope to simulate the behavior of real drums. The SDSV module featured a bending down effect that can be set to more or less amount of bending. VSDSX also features a bend up option and an optional FM modulation taken from the SDS7 module, the LFO can go from very slow to audio range modulation and can be optionnaly controlled by velocity.

SEPARATE OUTPUTS

The VSDSX have dedicated outputs for every voice like an original SDSV + PROM and CLAP modules.

You can choose from ALL to 1 Stereo Channel or Separate Channels for each voice.

TRIGGER SENSITIVITY CONTROL & VELOCITY

The drum synth is highly sensitive to the power of which a pad or a key is hit, VSDSX gives independent access to sensitivity tuning for each voice, the pitch of the tone, VCF cutoff, click trigger etc...You can also disable the volume velocity tracking and only set a pitch sensitivity which gives access to a similar feature than the "run generator" found in certain Simmons Systems.

GUI & AUTOMATION

The GUI features all the SDSV controls (with the same weird naming :) ) but can also give access to a full module display with more in-depth controls, most of the parameters can be MIDI learned and controlled by an external MIDI Hardware or automation.

MIDI MAP

By default VSDSX triggers are mapped to the MIDI GM standard but you can customize it to your liking using its MIDI learning function. The map can be saved globaly and will be recalled everytime.

CLAPTRAP VOICE

The VSDSX provides one voice which is based on the mighty Simmons ClapTrap, finely tuned against an original unit it reproduce the digital circuit, EPROM looping, Human feature and pitched noise source.
The original VCAs got something between an exponential and linear behavior useful for those almost gated claps, VSDSX adds a more pronounced exponential option, slightly increased tuning range on the low side and also provides an entire dedicated plugin if you feel like clapping someone's face with stereo widening capability using two emulated voices running with EPROM clock and filter offsets.

LOADING EXTERNAL EPROM DATA

The VSDSX provides one voice which is EPROM based (like SDS1 or SDS7) the imported original EPROM image(sample) will benefit from the bend and noise mixing feature with that crunchy 8bit sound.
Load your own custom made EPROM image. EPROM format is the same as VProm (U255 companded) for easy compatibility but it can also now load Linear PCM format(most of Simmons original EPROMS were Linear PCM).

VSDSX supports any size EPROMS binaries (.bin)

LOAD & SAVE FULL PATCH & BANKS in many formats (additional technical info in manual.)

  • Cross Platform capability (Windows VST2/VST3 and Mac AU(Audiounit).
  • 64bit build using latest OS and IDE(Windows 10 VisualStudio and Mac Xcode).
  • Updated GUI(graphic Interface).
  • Refined HIHAT and CYMBAL modules (more detailed sound process, better envelopes, more accurate sound source and features).
  • PROM voice now supports any EPROM image size without the need to specify it beforehand, it can also decode U255 companded & Linear PCM formats.
  • VSDSX now have MIDI Mapping capability, you can create a custom map to assign sounds to any MIDI notes you want (2 per voice) and save the config globaly.
  • New additional CLAP voice closely based on the iconic Simmons Digital ClapTrap from 1982 with additional controls and modulation capabilities, also provided is an entire dedicated Claptrap plugin with stereo widening capability using two emulated voices running with EPROM clock and filter offsets.
  • Additional modulation source VEL 2 MOD which use velocity to adjust the LFO modulation amount(per voice).
  • Global option to turn on "OSC Custom" changing all analog oscillators that use the typical analog SDSV shape to use a Sine shape.
  • Refined sound engine on many levels and tons of bug fixes.
  • The Hi-hat & Cymbal modules were pretty rare and unique sounding, mostly they were sample based, same configuration for both cards, but in a very particular way.

    Honestly, the metallic waveform has nothing to do with a real hi-hat or cymbal sound, you can hear its looping and the raw 8bit character, but: This is a CULT sound! If you play this with bending up or down while toying around with noise and filter, you get these famous cymbal sweeps!

    Velocity can also act on the sample rate and it sounds pretty original.

    Memory was expensive at that time so you cannot store a long sample and be cost effective.

    So Dave Simmons looped the short sound stored onto a 2732 EPROM, a trick also used by Roger Linn in the LM-1 but this time, the sample is read forward then backward.

    The loop plays all the time inside the SDSVs digital modules and only VCA and VCF are triggered, this configuration opens up to very long decay settings.

    The 555 Timer is the clock which set the speed of sample reading, the CD4516 are the counters and the CD4013 is changing the readout direction once counter reach the end.

    The data are stored as a linear 8bit format and decoded by the linear 8bit DAC.

    Hihat EPROM based circuit

    The original SDSV schematic and a lot of useful documentation found on the great simmonsmuseum.com website were priceless to design VSDSX VST.

    R&D for VSDSX

    Windows:

    Windows 7 to 10 and higher, 64bit host, plugin provided formats are VST2 and VST3.

    Mac OS:

    Mac OS (10.10) to Catalina/ Big Sur or higher, 64bit host, plugin provided format is AU (AudioUnits).

    About AudioUnits format:

    AU is Apple s proprietary audio technology, part of the Core Audio provided by Mac OSX. It is part of the operating system so it provides low latency and system-level support for the interface. Most DAWs developed for Mac OSX support the Audio Units interface due to its stability and system-level solutions (which also means faster processing). Apple Logic only utilizes Audio Unit format plugins, but other DAWs such as Ableton can also use these.

    One or two DAWs like for example Cubase do not support Audiounits directly yet but you can still easily load an AU plugin with the help of a VST host plugin, some popular solutions are DDMF Metaplugin or BlueCat's Patchworks, a popular free one that recently got open sourced is KUSHVIEW ELEMENT. You will find info and a direct link to latest free binaries at the support/OSX Support part of my website.

    Protools:

    Avid Protools only supports its proprieratary format AAX at the moment but you can still easily load an AU or VST plugin with the help of a VST/AU host plugin, some popular solutions are DDMF Metaplugin or BlueCat's Patchworks, others might be available that I am not aware of yet.

    Other info:

    32bit is not supported ATM
    Mac M1 should handle it fine even if it is not natively compiled for ARM.

    Read the VSDSX 2 Manual

    Get amazing details about the Simmons SDSV Drum Brain and master the VSDSX!

    VSDSX SIMMONS DRUMS MANUAL V2.

    VSDSX User Manual


    Read the Stereo CLAPTRAP Manual

    Master the CLAPTRAP extended bonus plugin!

    STEREO CLAPTRAP MANUAL.

    CLAPTRAP Plug-In User Manual


    Owner of 32bit version 1.0 wants to upgrade?

    GO HERE

    Change Log

    You can check your current version with a right click on the GUI.
    Updates for VSDSX VST are free until version 3.0

    01/25/21 - v2.0.2
    • Fixed wrong status on MIDI Map after a Map Reset.
    • Better support for Direct-X graphics (fix crashes on older systems).
    • Hihat fix wrong velocity always affecting Hihat bend instead of sensitivity.
    • Multi Out switch will stay consistent even on patch change througout the life of the instance.(it now resets to off on Project recall so don't forget to put it back on if it was, this is a tradeoff to avoid the annoying resets on preset change)
    • GUI fixes and color changes.
    • New keyboard control mode (claptrap).
    • Fix control voltages limit in key control mode(claptrap).
    • Catalina / Big Sur fix (Mac)
    • Auval fix (Mac)
    • Automation and preset system fix (Mac)
    • Now signed and notarized by Apple (Mac)
    04/19/19 - v2.0
    • Cross Platform capability (Windows VST2/VST3 and Mac AU(Audiounit).
    • 64bit build using latest OS and IDE(Windows 10 VisualStudio and Mac Xcode).
    • Updated GUI(graphic Interface).
    • Refined HIHAT and CYMBAL modules (more detailed sound process, better envelopes, more accurate sound source and features).
    • PROM voice now supports any EPROM image size without the need to specify it beforehand, it can also decode U255 companded & Linear PCM formats.
    • VSDSX now have MIDI Mapping capability, you can create a custom map to assign sounds to any MIDI notes you want (2 per voice) and save the config globaly.
    • New additional CLAP voice closely based on the iconic Simmons Digital ClapTrap from 1982 with additional controls and modulation capabilities, also provided is an entire dedicated Claptrap plugin with stereo widening capability using two emulated voices running with EPROM clock and filter offsets.
    • Additional modulation source VEL 2 MOD which use velocity to adjust the LFO modulation amount(per voice).
    • Global option to turn on "OSC Custom" changing all analog oscillators that use the typical analog SDSV shape to use a Sine shape.
    • Refined sound engine on many levels and tons of bug fixes.
    07/01/17 - v1.1
    • Small bug correction on the audio engine, a click could be heard at some particular setting while re-triggering a long decaying voice, oscillator's phase was incorrectly synced to trigger in certain cases causing audio clicks. Fixed now.
      Default bank gained some additional presets.
    06/30/14 - v1.0
    • Initial release.

    Get It !

    Get VSDSX v2 for Windows & MAC

    VSDSX 2.0 comes with both Windows & Mac Installers and Manual