Introduction | Features | Overview | Sound | Videos | Demo | Buy | History
.: Introduction
At the beginning of the 80s, a new bass synth appeared on the market. Aimed at bass-guitarists, it featured an in-built sequencer with slides and accents. Only about a decade later did it become one of the most popular instruments in certain styles of acid, techno, house and trance music. Since that, numerous copies and software and hardware emulations have been born, which all try to grasp the character of this wonderful synth. We did our best to reincarnate this instrument as an authentic-sounding, convenient and easy-to-use VSTi plugin. Countless hours were spent on analysis and measurements, with the goal of making the most-authentic sounding emulation. As a result of the research, SilverBox was born, 25 years after the creation of the machine.
.: Features
  • Authentic monophonic analog acid bassline emulation
  • Easy-to-use interface
  • Oscillator with saw/square waveforms
  • 18 dB/oct. analog modeled multimode filter, LP/BP/HP/peak modes
  • Sequencer with piano roll, accent & slide
  • External sequencer mode
  • Variable pattern length (1-16)
  • Advanced randomize functions
  • 16x oversampled distortion with minimum aliasing (soft, hard clipping, soft foldback, hard foldback)
  • Optimized DSP code using SIMD instructions
  • Customizable MIDI CC automation
  • Sequencer MIDI out
  • Custom skinnable user interface
For more information about available features, please visit the FAQ page.
.: Overview
What is SilverBox?

SilverBox is an authentic digital emulation of the world's most renowned and famous analog bass line machine. It's square oscillator accurately models the oscillator of this 80s analog beast, giving a spectrally different square wave for different notes. The in-built sequencer has the traditional behaviour with accents and slides. The accent circuit is probably the most difficult to faithfully reproduce virtually, and most other emulations simply fail to reproduce the typical barking sound.

Accent and filter

Most emphasis was on creating the best accent emulation possible, because no virtual plugin fulfilled our expectations. The same applies to the filter - most other emulators don't reproduce the typical resonance character thoroughout the entire frequency range at all.

Why is it different?

The most striking difference with SilverBox and most other emulators (besides sound) is the ease of use. You see the entire pattern instantly, no need to cycle through steps to see what's going on in the pattern. With dedicated rows for gate, up, down, accent and slide, you can alter patterns easily and quickly. The piano roll gives you an overview of the melody in a familiar way. The pattern functions give you an intuitive way of quickly and easily delete, shift, or randomize rows independently. The random functions allow you to set a random probability for each row, which allows you to create many similar random patterns at a click of button. Unlike the original which is difficult to program, SilverBox is really easy and fun to use.

"It is one of the most user friendly instruments these days and this makes SilverBox proudly stand out amongst others."

Alexander Arsov, Wusik Magazine

Sound quality

The second most important aspect was the sound quality. SilverBox uses oversampling where necessary, to minimize annoying high-frequency aliasing artifacts at internal distortion, typical with virtual instruments. With its sophisticated 16x oversampled in-built distortion engine, SilverBox can drive your basslines with an amazing +80 dB into four types of saturation, with nearly no digital aliasing artifacts. That means, if your host runs at 44.1 kHz, then SilverBox processes sound internally at 705.6 kHz!

"Silverbox sounds amazingly good. It definitely has the 303 sound and it doesn't sound artificial like some virtual instruments do."

Alexander Arsov, Wusik Magazine


Despite the extreme oversampling, SilverBox runs lightning fast on your SSE-enabled processor. Designed to utilize modern CPUs' efficient instruction sets, SilverBox processes 4 samples at once! This gives you a lightweight plug-in which allows you more instances, and leaves you more horsepower for the rest.

In addition to the standard features, SilverBox has a bunch of extras as well. There are additional four unique filter modes with bandpass, highpass and peak responses, at the same time retaining the typical resonance character. The MIDI out feature allows you to drive another software of hardware synth with the SilverBox internal sequencer. And the noise feature adds some hiss, to make the sound less digital and sterile.
.: Sound

Here are some sound samples which compare the sound of the original Bass Line to SilverBox.

Loop1a Loop1a Square loop, setting 1
Loop1b Loop1b Square loop, setting 2
Loop1c Loop1c Square loop, setting 3
Loop1d Loop1d Square loop, setting 4
Loop2a Loop2a Saw loop, setting 1
Loop2b Loop2b Saw loop, setting 2
Climax Climax Emmanuel Top - Climax v1.1 theme
Saw tweak Saw tweak Saw pattern tweaking

To hear more sound samples, please use the player at the right side of the page, or listen to the following demo tracks. Note that the demo sound player requires Macromedia Flash. All samples and demos were recorded at 44.1 kHz sampling rate.

Meller - Monotone Track featuring SilverBox
Vacyd - Real Contact 3 instances of SilverBox
Vacyd - Sludge 3 instances of SilverBox
Scoofy - Atom Ant Rhythm samples + 4 instances of SilverBox
Scoofy - Delysid Triplet demo with 2 instances of SilverBox

You can listen these demo tracks using the demo sound player on the right side of the page. They are listed at the end of the playlist.

.: Videos
.: Demo
The demo version has the following restrictions:
  • The sound drops out every 45 seconds.
  • The number of presets is limited to 16.


  • The installer doesn't create any additional files, folders or registry entries; just copies the files to the location you specified.
  • SilverBox doesn't give any sound until it receives MIDI input from the VST host, so you need to add some notes in your sequncer or press a key on your MIDI keyboard in order to hear sound.
.: Buy

Buy a SilverBox license and...

  • get an amazing 303 emulator
  • get fast, friendly customer support in email
  • get bugfixes free of charge (many bugs are fixed instantly)
  • get free updates automatically
  • check and test out new betas
  • get skinning support for custom skins (under development)
  • support the development of SilverBox and further plugins


  • Before purchasing, please make sure the demo runs fine on your computer.
  • The installer doesn't create any additional files, folders or registry entries; just copies the files to the location you specified.
  • After the purchase, the download link to the full version and the serial will be sent to your email address usually within 1 day.
  • Updates will be sent to your PayPal email address. If you want to receive updates to a different address, please tell us!
  • If you don't receive the download link within 1 day, please check your spam/bulk/junk folder! You can avoid this by adding our mailing address (found on the contact page) to the list of "safe" email addresses.


SilverBox VSTiWin49

If you have any questions about payment, please do not hesitate to contact us.

.: History
v1.22 (05.14.2009)
  • Added: automation for all individual steps in the sequencer. So now you can automate gate, up, down, accent, slide and pitch steps in the pattern.
  • Improved nonlinear filter, giving you warmer analog sound.
v1.21 beta (11.24.2008)
  • Added MIDI out
v1.20.4 (11.18.2008)
  • Fixed: note-off is detected correctly in Energy XT2
v1.20.3 (10.29.2008)
  • Fixed: resized window
  • Outputs are not grouped as a stereo pair
v1.20.2 (10.28.2008)
  • Fixed: randomize patch works for cutoff & tuning pots
  • Fixed: cutoff image load bug with custom skins
v1.20 (10.22.2008)
  • Fixed: registration window freeze in Reaper
  • Fixed: first note is played correctly
  • Bandpass/highpass/peak filters are normalized
v1.20 beta (06.05.2008)
  • Added a new function for randomizing presets
  • Added a new filter type: peak
  • Fixed: occassional crashes with multiple instances
  • Now supports custom skins!

v1.14 (03.18.2008)
  • Tuning quantize now works for MIDI CC too
  • Changed the color of LCD rectangles to darkblue
v1.13 (02.12.2008)
  • Fixed a bug in the Tuning knob. Tuning quantize now works correctly.
  • Now all knobs including the Tuning knob are vertical linear. For fine tuning, hold the Control key.
v1.12 (01.11.2008)
  • Added darker stripes to piano roll for black keys
v1.11 (12.29.2007)
  • Piano roll works by both clicking and dragging
  • Only active steps are displayed in the piano roll
  • Slight GUI changes
v1.1 (12.21.2007)
  • SilverBox can now be played from an external host!
  • Changed knob behaviour to linear vertical
  • Added subsonic filter for overdrive
  • Added MIDI CC for VCF tune and velocity sensitivity
  • Fixed FL7 issue
  • Slight GUI changes
  • Minor bugfixes

v1.0 (11.15.2007)
  • First public version