£199.99 Ex. VAT

Welcoming the original 'Tron to the family

The GForce MkII celebrates the extremely rare and highly coveted original dual manual ‘trons, the Mellotron® MkI/MkII and Chamberlin® Musicmaster.

Whilst M-Tron Pro IV continues to focus on the chromatic sounds of the Mellotron M400 and is probably the first ‘tron you’ll want, its GForce MkII sibling is a unique and exclusive library with specialist tools for tackling the rhythms, accompaniments, and unique playing styles found in earlier Mellotrons MkI/MkII and Chamberlins.

Originally conceived as the ultimate Home Entertainment Console, the UK-made 1963 Mellotron MkI/MkII was a dual-manual tape-based instrument. The left manual’s 35 notes replayed a combination of 18 Rhythms and Accompaniments (66 on the GForce M-Tron MkII*), and the right manual (also 35 notes) replayed 18 lead sounds (66 on M-Tron MkII*).

GForce MkII was designed for composers and producers who want access to the evocative tones of the original dual manual Chamberlin®, Mellotron® MkI, and MkII instruments. Special emphasis was placed on the Rhythms and Accompaniments, which capture a moment in time between the 1950s and late 1960s.


Artist's Opinion

I can’t begin to describe how wonderful this sounds. […] the sound quality is astounding, breathtaking.

Tony Visconti Thumbnail

Tony Visconti

Producer - Bowie, McCartney, The Moody Blues


Under each key of the original MkII was over 40 feet of magnetic tape. At the press of a button, a scrolling mechanism would move that tape so that one of six different sections could be replayed. These sections are referred to as ‘Stations’ and each conformed to a specific style, musical key and tempo. Obviously, it was impossible on the original to mix and match Rhythms and/or Accompaniments from different Stations.

On the GForce MkII, we’ve kept this methodology, but added ways where Rhythms and Accompaniments from different Stations can be mixed and matched, vastly increasing the possible permutations and flexibility of the instrument. GForce MkII also offers the ability to retune an entire bank while maintaining the host tempo.

What’s more, GForce MkII features a Dual Rhythm Mode where you can layer two Rhythms and Accompaniments from the Chamberlin and Melly MkI & II to create a fusion of hybrid rhythms and motifs. We’ve also taken care not to iron out the character of the original tapes so the contrast between US and UK recordings is a joy to behold… warts and all.


Artist's Opinion

Having restored and serviced countless ‘trons over the past 30 years and edited up the masters for use in this software, I am secretly thrilled at the way it looks and sounds. I know what one of these machines should sound like…intimately. This is a staggering product.

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Martin Smith

Streetly Electronics


King Hussein of Jordan, Princess Margaret & L Ron Hubbard bought into the MkII’s Home Entertainment concept. But in much the same way as a younger generation reshaped music using Roland TB-303’s & TR-909’s in fresh and imaginative ways, so too did The Beatles, The Moody Blues, King Crimson, Genesis, The Rolling Stones, who catapulted its magnificently grainy tones into the public consciousness via Strawberry Fields Forever, The Court Of The Crimson King, Watcher of the Skies, Nights In White Satin and 2000 Light Years From Home.

All the sounds on the GForce MkII are sourced from the MKI, MKII and Chamberlin Tape Archive curated by Martin Smith who prepared the recordings for this project. With these tapes undergoing extensive, but sympathetic tape restoration and tempo remapping, on GForce MkII both microphone and DI’d recorded versions of the lead tapes now sit side-by-side with combinations of rhythms and accompaniments, the latter of which can be synchronised to your host tempo and transposed to fit into your own compositions.

Artist's Opinion

I think I’ve only gotten 2 instruments over the past 30 years that I like as much. GForce MkII is an incredible instrument.

Mitchell Froom Thumbnail

Mitchell Froom

Paul McCartney, Peter Gabriel, Tracy Chapman...

Audio Demos



Apple macOS.

The GForce MKII is a virtual instrument in the following formats:

  • Standalone Application
  • AudioUnit
  • AAX
  • VST

The Minimum System Requirements are as follows:

  • Intel or Apple Silicon Mac via Rosetta2 Translation
  • macOS 10.15.x or above
  • 230 MB of disk space + 5GB for the library that may be installed on an external hard drive

Windows on PC.

The GForce MKII is a virtual instrument in the following formats:

  • Standalone
  • VST
  • VST3
  • AAX

The Minimum System Requirements are as follows:

  • 2GHz CPU with 2GB RAM
  • Windows 7 and above
  • 230 MB of disk space + 5GB for the library that may be installed on an external hard drive

Key Features

  • Rhythms, Accompaniments & Lead sounds from the 1960’s dual-manual Chamberlin & Mellotron MkI & MkII.
  • 132 tape-banks, several of which have never been previously released.
  • Over 4500 individual samples curated from The Streetly Archives.
  • Unique and authentic instrument with over 150 Patches.
  • Rhythm / Accompaniment & Lead mode, plus Dual Rhythm / Accompaniment mode.
  • Parallel Trigger option for Rhythms, Accompaniments or both.
  • Rhythm & Accompaniment Host Sync, Transposition, Tape Half Speed, Tape 2s-Rewind Time, Tape Reverse and Pan.
  • Individual key edit control (tape start, detune, tape pan, key click), & key edit presets save and recall.
  • Chord Finder visual-aid for playing matched Rhythms and Accompaniments.
  • Use one 88-note keyboard or two separate smaller keyboards to control each manual.
  • Reverb (modern or spring) and Delay effects.
  • Unlooped tape-banks for an authentic MkII playing experience.

GForce MkII Demo

The MkII Demo is designed to test the software with your system. As such it has a limited library (420MB) and is silenced briefly every 20 seconds.

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* Some sounds appeared on both the MkI and MkII.

Legal Notice
GForce Software and M-Tron Pro are trademarks of GForce Software Ltd. All third party product names used in this product are trademarks of their respective owners and are in no way associated or affiliated with GForce Software Ltd. These trademarks of other manufacturers are used solely to identify the products of those manufacturers whose tones and sounds were studied during development of this product. Mellotron and Chamberlin are registered trademarks of Marcus Resch.

The GForce MkII software incorporates élastique Pro V3 by zplane.development.

Buy MkII

£199.99 Ex. VAT


£199.99 Ex. VAT