Skip to Store Area:

Welcome to!

You have no items in your shopping cart.

You're currently on:

+ Click images to enlarge

GForce ChamberTron Expansion for M-Tron Pro

Email to a Friend

Be the first to review this product


Availability: Immediate email delivery.

Add Items to Cart

Quick Overview

Download License! Email Delivery!

Key Features

The sounds of the legendary ChamberTron
Over 40 new tape banks
35 Notes per tape bank
Optional ChamberTron Interface design
100s of Patches, many from luminaries including Dean & Jarrod (I Monster), David Hentschel (Genesis & Elton John) & Jem Godfrey (Frost)


If you're unfamiliar with Chamberlin® musical instruments, please take the time to read about them in the Original Instrument section and check out the video showing our Chamberlin instruments. Because if you thought that tape playing instruments started and ended with the Mellotron®, you'll probably be blown away to discover that the entire tape playing instrument genre was invented by a Wisconsin based inventor, Harry Chamberlin, back in the 1950s.

Artists who've used Chamberlin instruments over the years range from Stevie Wonder, James Taylor, David Bowie, Marvin Gaye, Mitchell Froom, Three Dog Night, Todd Rundgren, Gino Vanelli, Edgar Winter, The Moody Blues, Elton John, The Beach Boys, XTC, Patrick Warren, Tom Waits, Kanye West, Jon Brion and countless more.

However, the sad truth is that we'll probably never know all the recordings the Chamberlin appeared on because the American Federation of Musicians kicked up a huge fuss back in the day and even banned the four manual M4 completely.

Aside from the 3 Violins sound, (originally called 'Violins' on the Chamberlin) which appears on both the Mellotron and Chamberlin library, all other sounds are unique to each manufacturer and while arguments continue to this day as to 'which is best?' we'll ignore such a fundamentally stupid question and state that Chamberlin recordings are widely acknowledged to have a more natural and uncompressed quality about them.

Chamberlin sounds also contain more natural vibrato and with the Chamberlin M series keyboards, the tapeheads had a greater bandwidth than the M400 equivalent which gave it a more 'hi-fi' edge.


The Instruments

This expansion pack focuses on the sounds from the Chamberlin keyboards, in particular our extremely rare four-manual Chamberlin M4 and one-off M1 Remote with custom MIDI Interface.

The M4 is one of only four made. It cost over $10,000 when new, in the early 70s, and was originally owned by Three Dog Night. Weighing in at a mighty 300 Kilos and containing 32 tape banks, it's amazing to us that Three Dog Night actually toured with it especially considering the constant adjustment necessary to keep it in tip-top working order. Other M4 owners include Mike Pinder and Mitchell Froom & The Lettermen.

Given its rarity it'll come as no surprise that we've spent a small fortune acquiring it, then restoring it properly and now maintaining it. This is a truly beautiful sounding instrument and we hope you'll be as blown away with the M4 sounds that help make up this collection as we are.

Similarly, our M1 Remote is one of only six made and rumoured to be one of only four still alive. Ours also has the unique honour of being controlled by a custom built MIDI interface and was restored by Richard Chamberlin (Harry's son) for actor Vincent Gallo before finding its way into our hands. While it contains the standard eight sounds, it's the quality of these sounds that speak volumes.

Finally, some sounds that have been taken from a Chamberlin 600 as well as a unique 'Variety' effects tape made for a Rhythmate 25 tape-based drum machine.

According to Richard Chamberlin, the only other Rhythmate 25 he's aware of is owned by Chamberlin player par-excellence, Patrick Warren. However, it seems that our 'Variety' effects tape for this drum machine may be the only one in existence. That helps make this expansion pack a unique treasure trove of beautiful rarities.


The Sounds

Naturally though, some audio restoration work has taken place. Over the years some tapes have become worn and on a few sounds demagnetization has occurred, such are the joys of magnetic tape-based instruments.

Where a note has been sufficiently damaged enough to become a problem, an adjacent note has been pitched and supplemented.  However, we have been very careful in any noise reduction process not to squeeze the life and character out of the sounds. Thankfully though, given the original immaculate recording process (Harry was smart enough to use Neumann U47s on the recording sessions) and the trouble taken in maintaining the instruments properly, we had such a good starting point there was no need to be savage.

Occasionally, there is more than one version of the same sound. Wherever you see this you'll know that each set has come from a different Chamberlin instrument or set of tapes. For example Vibes 1 were taken from the Chamberlin M4 and these are the most perfect. Vibes 2 were taken from a Chamberlin 600 and are less perfect. Finally, Vibes 3 were taken from the M1 Remote and are largely raw recordings.

The only soundest that is not a bona-fide Chamberlin sound set is the second effects bank. This bank is something that we recorded ourselves and contains squeaks, squeals, snatches and tape rewind noises, in addition to a few musical ideas created and recorded by ourselves. Someone, somewhere will undoubtedly make good use of these and we can't wait to hear how. Please keep us informed.

As a footnote, although reliable and corroborated information is hard to come by, it's estimated that approximately 700 Chamberlin instruments were made between 1951 and 1981. However, it's no denying that the Chamberlin M1 was the most reliable and the M4 (and Harry's personal version of this, The Riviera) the most coveted. In this collection you have the sounds from both of these instruments together with patches created by some of the finest sound designers, artists and real Tron users out there, including David Hentschel (Genesis, Elton John), Dean & Jarrod (I Monster), Richard Norris (The Grid & Beyond The Wizard's Sleeve), Gaz Williams (Rocketgoldstar) and Jem Godfrey (Frost).


Works With


Take a Tour


M-Tron Pro Expansion Packs are only available to registered users of M-Tron Pro. Additionally, they are exclusively available as direct downloads at

Click to enlarge image


The Original Instrument

While we love and admire the engineering of the original hardware machines, we also think hardware and good software should sit side-by-side. Because although the hardware versus software debate still rages, ad nauseam, the simple truth is that there's no definitive answer as to which is best. Just as there is good and bad hardware, there is good and bad software and the answer to this conundrum will depend on all manner of things including your personal perspective, available space, your technical savvy, your preferred working environment and of course your finances.

For example, do the majority of musicians looking for ‘that sound’ really care to maintain a forty-plus year old instrument, sourcing rare parts when they wear out or break?

Naturally we care, because we feel that we’re custodians of these instruments and while many other software companies simply hire-in instruments to record or model, we consider this bad practice. In our opinion good practice is when you've lived with and loved the original instrument's character and foibles for a considerable time before beginning any emulative process. Because, then and only then, do you stand a chance of capturing some of the instrument's soul and character within the software alchemy.

It's a simple dogma but you'd be surprised at how many software companies ignore this in favour of marketing hyperbole. Indeed, when we explained our philosophy to the marketing director of one such company, he said "No one really cares" and strolled off to no doubt perpetrate more marketing myths.

For us that fundamental understanding and love for an instrument is what really matters when trying to transplant its character. You see, we can tell the difference between good or bad, lazy or indifferent, marketing bullshit versus a real love for the authentic, because we’ve been immersed in these instruments for over 30 years. And in the case of Streetly, over 50 years!

But ponder this - while we’ve thrown countless bags of money at the purchasing and maintenance of all manner of tape replay instruments from Chamberlin’s to Mellotrons, we’re the exception. We’re committed (some would say ‘certifiable’) and we do it so that you don’t have to.

If you want an M400 plus all the tapes we supplied with the M-Tron Pro, you'd be looking at £20,000 plus, as opposed to the M-Tron Pro's £140. Likewise, if you wanted to buy the physical tape frames of a Streetly Tapes Volume for your original M400 you’d be looking at a price tag of at least £5,000, whereas at 1% of that each Streetly Tape Volume represent amazing value for money.

It’s something worth bearing in mind the next time that someone tells you that hardware is better than software.