In the Lab: GForce Software M-Tron Pro IV

[Dr Mike Metlay]

IN THE BEGINNING WAS THE WORD.... 

 

...and the word was "Mellotron".

 

 

The Mellotron was a legendary line of keyboards whose history I really don't have space to go into here. It was, effectively, an analog sampler: each key had a length of tape and a playback head under it. Press a key, the tape was drawn across the head, and a note played. You got up to 8 seconds of sound, then the tape ran out. Release the key, and pwang it rewound itself for the next note in about 2 seconds.

 

The Mellotron was the sound of "Strawberry Fields Forever", of "Daniel", of "Watcher Of The Skies", of "Nights In White Satin". It was the sound of early Tangerine Dream, of Larry Fast's first Synergy record (well, everything that wasn't a Minimoog or Oberheim SEM)... it was the sound of the era just before the string machine. It was bottled nostalgia, a quirky and uniquely sonorous instrument like none other. It was the anchor of the faux orchestra, the Rock upon which Progressive was built. (Progressive Rock. Get it? Yeesh, tough crowd.)

 

Unfortunately, from a practical-use standpoint, the Mellotron was also a gold-plated sewer pipe full of fail. 

 

It was heavy, fragile, finicky, phenomenally unreliable, and prone to so many different types of failure that Rick Wakeman once said that he couldn't find enough words or time to write down all the ways he hated it. Mellotrons were held together with duct tape, controlled with variable voltage supplies so they didn't change pitch when the stage lights came on, and despite their relatively high cost were regularly kicked or pushed off stages into the audience for screwing up yet another concert.

 

Other machines were built to try and fix its problems: the later Chamberlins (the old ones were where Bradmatic stole the design of the Mellotron from), the Optigan, the Orchestron, the Birotron, the Chilton Talentmaker... And they all had their own special forms of suckage that made them just as nasty an experience as the original, but just in a bunch of unfamiliar new ways.

 

This led to what I call The Mellotron Paradox:

 

I love the sound of the Mellotron. Love it, love it, love it.

I hate the Mellotron. Hate it, hate it, HATE IT!

 

If I was asked to take part in an electronic music "orchestra" where I was given a single instrument to play, I would want my part to be a Mellotron part. I would rather play Mellotron sounds than almost anything else out there today.

 

If I was told I had to do it with a real Mellotron, I'd start drinking heavily and contemplate a career as a cartoonist instead.

 

Fortunately, with the rise of digital samplers, it became possible to separate the sound from the instrument. David Kean and others sampled Mellotron sounds and stored them as sound libraries that could be purchased on CD-ROM and loaded into any sampler.

 

As sampled instruments went, the Tron was pretty much ideal: each note sounded the same and had no timbral variation when played over and over, so a single sample could represent it fairly accurately. Mellotron sounds were stored on metal frames holding all the tapes in place and ready to drop into the Tron. Each frame had 35 notes times 8 seconds per note, or 280 seconds of mono audio. Very roughly, you could digitize a single Mellotron sound at 16-bit/44.1 kHz resolution in a bit less than 25 MB of disk space, so a 650 MB CD-ROM could hold a fair number of Tron sounds, ready to map out and use.

 

From that point on, you could get sample libraries, various setups for samplers from Akai, Roland, E-Mu, etc. But what really got the Mellotron back into the hearts and lives of musicians everywhere was a tiny and unassuming plug-in that was part of the very first wave of native VST virtual instruments.

 

It was called M-Tron.

 

 

In the year 2000 – when native VST plug-ins were making their first appearance in the world of computer music – a small UK-based company called GMedia Software created M-Tron, which was nothing more or less than a virtual sample player based on the Mellotron M400, the classic white single-manual Tron that most people think of when you say "Mellotron."

 

It was a very simple program. What you see in the screenshot above (pre-Mac OS X, no less) is what you got:

 

• a 35-note keyboard

• controls for volume, tone, and pitch

• a 5-position rotary selector for three sounds or positions in between that blended the adjacent ones, and

• (under a little flip-up cover) sliders for sound attack and release. 

 

You clicked on the letters A, B, or C to pop up menus of 28 available sounds, chose them for each "tape track", and then played them. The end.

 

Except, of course, it wasn't the end. It was just the beginning of a long and very strange trip.

 

M-Tron showed up everywhere, as people were able to rediscover that old Tron magic for very little money and really no hassle at all. It was barely tweakable, but it sounded great, and the selection of instruments was fun and inspiring. Even better, you could pay to expand the library of sounds by buying more tape banks as add-on libraries.

 

Some of the sounds were the great classics, like the Mellotron MkII choirs, strings, and flute that appeared pretty much everywhere. Others were obscure as obscure could be, including a pair of BBC sound effects samplers that as far as I know were deleted from the library and never reissued due to rights problems. (One of them contained samples of the Beatles – not their music, but the boys themselves. Paul asking, "Who do you fancy for the Nationals?" and John stating "Give the pop stars a fair share of the country's wealth" and "I don't much care where it comes from, you know, as long as it's there.") The main thing was that they were there and easy to access... and most people who weren't Tron aficionados had no idea just how many there were!

 

Over the next decade, GMedia (now called GForce after the beginning of a partnership with French software house Ohm Force) collected their own ideas and requests from users to take the base sounds of M-Tron and put them in an engine with more flexibility and power.

 

The result was called M-Tron Pro.

 

Released in 2009, M-Tron Pro was a surprisingly powerful instrument. It now loaded two different tape frames, A and B, and with the touch of a few buttons you could edit A, B, or both at once (via the Link function shown above). Layer A parameters were framed in red while editing, Layer B was in green, and Link was blue. A slider above the keyboard let you split and zone the key ranges. Each layer could have its tape sounds played back at half speed, reversed, or both, and could have its own detune value, pan position, and more. You could even move the starting sample of the playback to get a sharper attack on sounds.

 

There was now an LFO, a multi-mode resonant filter (!), proper envelope controls, velocity and aftertouch sensitivity, MIDI CC mapping, built-in delay and ensemble effects, and a popup menu that could load entire sets of parameters and sounds for two layers at a time as a full program.

 

In addition, GForce began issuing more and bigger libraries of previously unheard sounds, which at this time of writing spans some 15 collections (more on those later).

 

Many years later, an updated version III added a resizable UI,  and a Brake control that simulated pressing down on the main drive roller to slow down sounds (using the Modulation Wheel). That incremental tweak left people wondering, "Is that it?"

 

The release of the MkII plug-in, which emulated the dual keyboards and specialized controls of the original Mellotron MkII, raised more questions than it answered. MkII was a terribly cool program in and of itself, but if (as GForce said) it was a completely separate product, what was going to happen to the beloved M-Tron Pro?

 

Well, as of a week or two ago, now we know. Wipe your feet on the mat, put on your white coats, and come with me into the GearLab – and I'll introduce you to GForce M-Tron Pro IV.

 

 

There's a fair bit to uncover, and over the next few days I'll run down this latest version of one of the most popular virtual instruments of all time. We'll look at its expanded sound design options, its tweaks to allow for more of the realism that Tron purists complain are missing from any digital version, and its expanded and vastly improved library browser.

 

There is a demo version available at the GForce website if you want to try it out and follow along, and we're hoping that someone from GForce Software itself will be joining us to answer your questions and comments.

 

Come on, let's have some fun! 

 

mike

 

 

 

 

[Chris Macleod]

Thank you Mike. As you know, I've been with GMedia Music and GForce Software since the beginning so I'm looking forward to interacting with the group. 🙂 

Chris

[Dr Mike Metlay]

BUT FIRST, A LITTLE ROADMAP

 

The basic format of M-Tron Pro IV hasn’t changed radically from that of M-Tron Pro:

 

• A patch begins with one or two Layers, A and B, each of which has its own completely independent settings.

 

• Then one or both of the Layers go through a series of effects (“FX”) before being heard.

 

• There are a few global settings for performance purposes as well, and a comprehensive MIDI CC assignment scheme.

 

• A patch browser lets you choose, edit, and save patches, starting with the patches that came with whatever tape banks you have loaded into the plug-in.

 

And that’s how I plan to break up these postings, so that’s what you have to look forward to.

 

Next up: Layers, and how they interact during editing and performance.

 

See you soon!

 

mike

[Doerfler]

I have been waiting paitently for this.   

 

I upgraded 3 weeks ago, don't remember when I purchased M TRON PRO originally, G Force was unable to provide that info once they migrated 

 

to their new servers in 2020. So we know it was before then. 

 

Yes,  in addition to being musical, this program is fun. 

[Dr Mike Metlay]

On 7/28/2023 at 12:14 PM, Chris Macleod said:

Thank you Mike. As you know, I've been with GMedia Music and GForce Software since the beginning so I'm looking forward to interacting with the group. 🙂 

Chris

Glad to have you here, Chris! I'm hoping that folks will have questions that you can answer. Onward!

 

mike

[Dr Mike Metlay]

A TALE OF TWO TRONS

 

The basic sonic element of M-Tron Pro is the Layer. One Layer contains one tape bank (set of sounds) with 35 different samples, with the following controls:

 

TAPE: parameters relating to how the tape is played back when a note is played

LFO: a basic source for cycling modulation of various parameters

FILTER: a multi-mode resonance filter with adjustable key tracking and an ADSR envelope to control cutoff

AMP EG: an ADSR envelope to control loudness

PERFORMANCE: settings for response to pitch bend, velocity, and aftertouch messages

 

There are also controls for the Layers themselves.

 

In this picture, the A button has been pressed to select Layer A for editing. All controls are highlighted in green, and changing any control changes that parameter for Layer A only.

 

 

In this picture, the B button has been pressed to select Layer B for editing. All controls are highlighted in red, and changing any control changes that parameter for Layer B only.

 

 

Note that for illustration purposes, I’ve changed a few parameter settings in an obvious way so you can see the difference between A and B – for example, Attack Start, Pan, and Filter Cutoff. You can also see the horizontal line above the keys, which indicates that unlike Layer A, which uses the entire keyboard, Layer B is restricted to the lower half.

 

Clicking the LINK button, as shown here, turns all controls blue.

 

 

Note that when Link is activated, all control values are displayed at their current settings for Layer A. 

If you touch any control, both Layers’ settings will immediately jump to that value, and you won’t get any visual warning if you change a setting in Layer B. 

 

That’s just something to keep in mind, because in general you’ll start off in Link mode and adjust the parameters for both Layers at once. Once you’re in the ballpark, then you can go back and forth and adjust parameters by Layer. In practice, it’s actually rare to get that far into programming a patch and suddenly want to do something drastic and global.

 

When you click on the name of the tape bank loaded into a Layer, you get the following pop-up:

 

 

This is a mini-browser to select a particular sound for that Layer. You can also clear the Layer if you don’t plan to use it. The pop-up is resizable to make the print easier to read. Oh, and the S button in the bank name window solos that Layer.

 

Next time: The parameters in each Layer and what they do.

 

See you then!

 

mike

[Dr Mike Metlay]

WHAT’S ON THE FRONT PANEL?

 

Last time I explained how Layers work. Now it’s time to dive into the controls in each Layer, which are simultaneously simple and powerful.

 

TAPE

 

 

For many players, the original version of M-Tron, complete with a grand total of two controls that weren’t on the original, was perfectly fine for their needs. Subsequent versions have added a few synthesis features, but also have been concerned with adding the quirks of the original hardware – along with the option to turn them off.

 

The first version played the tapes forward, just like the real thing. The second version added the ability to play tapes in reverse or at half speed, or to start playing notes from a later starting point on the tape. The third version added braking (which we’ll get into later on). M-Tron Pro IV adds even more options to provide a realistic hardware Tron experience.

 

Many of the controls will be familiar from previous versions of M-Tron Pro, but the layout is a bit more intuitive and there are a few new knobs.

 

The top left and bottom have the controls you’d be used to from the previous version:

Tune by ±12 semitones,

Detune by up to 50 cents (half a semitone),

Attack Start (starts notes from a point on the tape that is later than the tape’s physical start point) by up to 2 seconds,

Pan, and

Level.

There are also ½ Speed and Reverse buttons.

 

The new features can not only add authenticity but also a variety of interesting sound tweaks. Essentially they model variations in the speed of the motor pulling the tapes – these can be at a relatively low frequency (Wow), higher frequencies (Flutter), or a combination of the two. 

 

Each has its own Level and Rate controls, with a global Instability knob to introduce rate variations. The Wow rate ranges from 0.1 to 4 Hz, and the Flutter rate ranges from 10 to 70 Hz.

 

While these controls can add a nauseating level of authenticity to the sound of the Tron (the originals' motor speeds were notoriously sensitive to voltage fluctuations), they can also be used as a pair of frequency modulation LFOs, one running at a much higher rate than the other. If you set the rates and amounts differently for the two Layers, you can introduce some very cool chorusing and vibrato effects that at times approach the unique sound of the famed Uni-Vibe pedal.

 

LFO

 

 

The LFO’s function set has been expanded greatly.

 

While the previous versions only affected pitch, the new LFO can modulate pitch, filter cutoff, pan position, or level.

The LFO offers five waveforms: sine, bipolar and unipolar square, ramp (rising sawtooth), and random.

The Rate control ranges from 0.125 Hz (one cycle per eight seconds) to 10 Hz, and when the Sync button is active, from 16/4 up to 1/32.

 

There are two new controls as well.

The first is Smooth, which slews sharp waveform transitions to take the sharp edges off the waveform. Note that this amount is proportional to the Rate, so the waveshape doesn’t change if you turn the Rate up or down.

The second is Fade In, which gradually adds the LFO signal over a period of up to 5 seconds.

 

While this updated LFO section now gives M-Tron Pro some very cool synth-like features it lacked before, the one thing I really miss here – really, the one thing I feel is lacking in the entire engine – is an LFO Shape Invert button! It would be great to throw the A and B LFOs out of phase for panning and filtering cycles, or modulate with a negative unipolar square wave or a falling saw. 

 

I guess I can hope for GForce finding the front panel space to add a tiny button in a later update, or add a function like shift-clicking or option-clicking on a Shape button to flip the polarity, complete with an inverted graphic… but if that’s my only major complaint, that ain’t bad at all!

 

FILTER / AMP EG

 

 

The Filter bears a very strong resemblance to the previous version’s; it’s still a state variable filter model that can act in lowpass, highpass, or bandpass modes.

 

However, there are now two filter Types to choose from – Type 1 is the original, and Type 2 is a new model with a slightly warmer and richer sound and a smoother timbre when the Resonance is cranked up.

There’s also a bipolar control for keyboard Tracking, up to ±150%. Note that the filter doesn’t self-oscillate, so you can’t get an extra sine wave out of it.

 

The envelope generators for the Filter and Amplifier (AMP EG) are still ADSR type, with maximum stage times of over 24 seconds. Minimum Attack and Release times are 5 milliseconds, and Decay time goes down to zero. The Filter Envelope Amount slider works as before.

 

PERFORMANCE

 

 

The Performance section covers how each layer responds to MIDI Pitch Bend, Velocity, and Aftertouch messages. As on the previous versions, velocity can control Amplitude and/or Filter cutoff.

There’s now a window to set Bend Range anywhere from 0 to 12 semitones.

On previous versions, aftertouch response was monophonic and could only be routed to Filter cutoff. Now, aftertouch reception is polyphonic, so individual notes can be shaped by finger pressure. Aftertouch now not only controls cutoff but can also be routed to braking.

 

“What’s braking,” you ask? It’s a technique used by some hardcore Mellotron players who were very brave about potential harm being done to their machines or tapes, where the player pressed gently on the turning motor shaft to force it to slow down – stepping on the brake, as it were. At zero braking, the Mellotron plays as usual; at maximum braking, the entire mechanism grinds to a halt. I have to admit I’m not sure you could even do that on a real Tron, and what it would do to the guts if you tried!

 

On M-Tron Pro version 3, braking was an on/off function, and when it was on, the mod wheel was hardwired to control it. As with the hardware, hitting the brakes applied to all sounding notes at once, so polyphonic aftertouch control is a very nice touch that you can’t do with real tapes.

 

Next time, we’ll delve into the FX section, which is greatly expanded from previous versions. See you then!

 

mike

[Dr Mike Metlay]

UNINTENDED SIDE FX

 

There have been effects processors in M-Tron since the second edition – the tempo-syncable Delay and multi-voice Ensemble are a great part of its signature sound. For M-Tron Pro IV, the FX section has been expanded – both in the number of available effects but also in the flexibility of their implementation. You can actually come up with unusual detuning and filtering/phasing sounds with the right settings, so mess around and surprise yourself!

 

 

The first section of the FX panel is simple but very important, as it’s for one of the biggest new features in M-Tron Pro IV. In previous versions, the FX settings applied to both Layers, and both Layers were mixed before going through the FX. Now it’s possible to independently use or bypass the FX chain for each Layer. The A and B buttons do that for you.

 

Each of the four FX – AMP, DELAY, ENSEMBLE, and REVERB – has a small yellow LED indicating whether it’s active or not. Click it to bypass that effect.

 

You’ll also note a small FX Lock icon for each block. When you click that, the current FX settings are locked in place, and won’t change even if you change presets. This is handy if you’re switching presets during a set and want to avoid having your tight room reverb suddenly become the inside of an empty supertanker.

 

AMP

 

The Mellotron isn’t normally associated with blasting guitar amps, but the effect isn’t unheard of. Ian McDonald of King Crimson used to run his MkII through a Marshall stack. And hey, if it’s good enough for Crim…

 

The Warmth control adds some nice low-mid push, for that classic analog warm and fuzzy feeling.

 

Noise is something for the real purists: it’s a steady drone of low-level noise like you’d hear from a real Tron’s output, regardless of whether or not you’re playing anything. Alas, there’s none of the Tron’s grinding motor drone here, and I’m lying when I say ‘alas’, because nobody wants to hear that. Besides, it’s acoustic noise, so it doesn’t come out of the output jack anyway.

 

Saturate is where things get really ballsy. It’s a mixture of tube and transistor overdrive circuit models, and it’s very easy to turn it way up into serious distortion.

 

Your mileage will vary; I prefer a bit of Warmth, no Noise, and a little bit of Saturate when I play, but that’s just me.

 

DELAY

 

What’s not to love about a good-sounding modeled analog bucket brigade delay? The M-Tron Pro IV Delay has all the cool features you’ll need, plus a fun extra or two.

 

Both Left and Right channels have Time and Feedback controls. The Link button (with the chain icon) causes either set of controls to work for both channels at once. Note that cranking the Feedback all the way up will cause the echo to regenerate forever, but you can’t force the delay lines into runaway.

 

The two buttons next to that are the Delay Sync and Delay Cross-Feedback controls. Delay Sync changes delay time from milliseconds (o to 2000) to bar/beat increments (1/32 to 4/4), and Cross-feedback sends feedback from each side to the other side, for ping-pong effects.

 

Finally, there’s a dry/wet Mix control.

 

Trivial note: there’s a small glitch (not really a bug) in the Delay controls. When the Delay is bypassed, he Sync button has no effect – times are always displayed in bars/beats. This is a non-issue, as the button works correctly as soon as you engage the effect.

 

Much more important note: I forgot to mention earlier that when you move a parameter, its value is displayed in the top-level bar where preset names normally appear. Sorry about that!

 

ENSEMBLE

 

The Ensemble has a very cool new feature: not one but two types of ensemble effect.

 

Type 1 is the same as the Ensemble in M-Tron Pro’s previous editions. Basically, for every note you play, it adds pairs of panned/detuned voices, from 2 to 8, at fixed pan positions. Detune and Mix control the spread of tuning and wet/dry balance. Click the number of Voices to cycle through 2, 4, 6, and 8.

 

Type 2 is a completely different effect and one that’s quite cool. According to GForce, Type 2 is based on the unusual ensemble effect in the Roland RS-505 Paraphonic keyboard. The Voices display becomes a Tone knob, which emphasizes or cuts the highs. This effect is much more pronounced than Type 1, and needs to be used sparingly.

 

If you’re playing a patch with a lot of stereo separation, Type 2 will preserve that imagining closely, whereas the more of Type 1 you add, the more the extra voices with their fixed pan positions will drown out the original. Type 1’s spread effect is most pronounced when the original sound is mono or close to it. I usually like 2 or 4 voices, maybe 6… 8 turns into mush very easily.

 

Basically, just remember that with Type 1, more (whether more Detune, more Voices, or more wet Mix) is not always better!

 

REVERB

 

This is a surprisingly full-featured reverb with plenty of parameters to tweak to taste. All the usual suspects are here: 

 

Pre-Delay (up to 1 second) 

Decay (tail length), up to effectively infinity (freeze) at its highest value)

Room Size

Modulation for the reverb tail, with Frequency from 0.1 Hz to 2 Hz

Damping, which is a “tilt control” that rolls off highs to the left of center and rolls off lows to the right of center

Mix for wet/dry blend. 

 

Unlike the other FX, the Reverb has presets. Numbered 1 to 5, they can’t be overwritten, but they serve as a good starting point for your own Reverb settings that can of course be stored with your preset.

 

The presets range from very tight and close spaces to ridiculous near-infinite caverns. And I am lying when I say ‘ridiculous’ because I love that sort of thing. Mmmmm-MM!

 

Next time, we’ll take a look at global performance settings, including MIDI Learn, and talk about the features on the Settings panel. See you soon!

 

mike

 

[Dave Bryce]

Really deep dive so far, Dr. Mike!  

 

I’ve been an owner of a Mellotron 4000D rack for many years.  I picked up a copy of M-Tron Pro IV a little while back, and frankly I’m surprised at how much better I like working with the software than the hardware.  So much more power and flexibility, so much more control available, so many options to choose from.  

 

It’s kind of easy to understand how M-Tron has become an industry standard for so many people.

 

True story: I sold my 4000D on reverb.com a few weeks ago.  No regrets.

 

dB

[Dr Mike Metlay]

On 8/9/2023 at 8:02 PM, Dave Bryce said:

Really deep dive so far, Dr. Mike!  

 

I’ve been an owner of a Mellotron 4000D rack for many years.  I picked up a copy of M-Tron Pro IV a little while back, and frankly I’m surprised at how much better I like working with the software than the hardware.  So much more power and flexibility, so much more control available, so many options to choose from.  

 

It’s kind of easy to understand how M-Tron has become an industry standard for so many people.

 

True story: I sold my 4000D on reverb.com a few weeks ago.  No regrets.

 

dB

 

Wow! Now THAT is an endorsement, although I honestly can't say I am that surprised. In the next installment, I'll talk about one or two features that only the 4000D had, which had purists shying away from M-Tron Pro... but which are now in M-Tron Pro IV.

 

mike

 

[Dr Mike Metlay]

TAKING CONTROL

 

Last time, we got most of the way down the front panel of M-Tron Pro, and now it’s time to finish our journey, with a look at keyboard performance controls, MIDI CC assignment, and finally the Settings menu.

 

KEYBOARD CONTROLS

 

 

The keyboard performance controls on M-Tron Pro look a bit like that of a real Mellotron, with knobs for Volume, Tone, and Pitch. Note that these are global controls, and Pitch is a fine tuning control rather than pitch bend (M-Tron Pro IV already responds to MIDI Pitch Bend, as explained earlier). The real Tron’s horizontal A–B–C lever to move the tape tracks under the play heads is replaced by a vertical A–B control to blend the two Layers.

 

Over on the right are two buttons to enable the Brake and Rewind functions. We mentioned Brake earlier; when it’s enabled here, MIDI CC 1 causes playback to slow down all the way to a stop.

 

Rewind is one of the last remaining behaviors of real Trons and digital hardware emulations that hadn’t been added to any Tron plug-in before. It simulates the fact that Mellotrons can’t rewind their tapes instantly when you let go of a key; the tapes have to be carefully retracted back into place for the next note. A tape plays for 8 seconds until it is stretched out to full length and the note stops; it retracts in about 2 seconds.

 

When Rewind is turned off, retriggering a note starts the sample at the beginning again. When it’s turned on, the start of the sample is wound backward at 4x the playback speed; if you rapidly retrigger a note, you “catch” the note in the middle and play from there, just as you could on a real Mellotron. This behavior is separate from setting the Attack Start value.

 

The keyboard itself has one more trick up its sleeve: if you click on the lower marker for keyboard range of one or both layers and pull it to the left of the lowest G, this happens:

 

 

You get seven more notes! These sounds aren’t new samples – they are derived from existing samples. Exactly how the plug-in does it, I don’t know; I don’t think they’re decimating notes one octave up, or pitch-shifting the lowest note again and again. Hopefully Chris from GForce can weigh in on this?

 

MIDI CC ASSIGN

 

Click the CC button at the top left of the plug-in to open the MIDI CC Assignment overlay:

 

An unassigned control has two dashes on it. In this picture, I’ve selected the A–B lever for assignment. The dashes are blue because this control is global for both Layers, as are the other keyboard controls and FX parameters.

 

For parameters that are separate per Layer, each Layer can have its own CC assignment, with A selected in green and B in red. Here's the Filter Cutoff, a nice big easy-to read example:

 

 

Just click on the parameter you want to set, move a control on your MIDI device, and the CC will be assigned. Double click an assignment to clear it, or click the Clear box at the top of the page to clear everything. In the above example, we select and set the top number, then select and set the bottom number.

 

Controls can be mapped to MIDI for 38 per-Layer parameters, 24 global FX parameters, and 6 global performance parameters. That’s 106 CCs in all, which is a lot! However, there’s a workaround to give you more breathing room in that regard, and it’s found in the Settings menu.

 

SETTINGS MENU

 

Click on the gear icon to pop up the Settings menu:

These are parameters that you will usually set and forget. The menu shown above is the one from the standalone app; the top half is only used in standalone mode, and the parameters in the bottom half are available inside the plug-in in your DAW.

 

The top half is all pretty straightforward: you choose audio output device with sample rate and buffer size – the lowest setting is 64 samples, which worked great on my relatively old dual-Xeon Mac Pro Server. All available MIDI inputs are shown, and you can decide which ones talk to M-Tron Pro IV.

 

The second half starts with that workaround I just mentioned: you can set Layers A and B to different MIDI channels if desired, to open up more CC options and/or to play two Layers from two different MIDI devices.

 

The next function does what it says: it prevents M-Tron Pro IV from cutting off notes when you hit Stop in your DAW.

 

Browser font scale and Parameter display time can be set to suit your eyes.

 

Mod wheel LFO sensitivity can be set to Low, Medium, or High – independent of MIDI CC 1 control of braking, it can also goose the LFO depth a bit.

 

Finally, Extended range quality can be set to Efficient, Standard, or Pro. This determines the quality of the extra notes at the bottom of the keyboard range; I was playing chords on my old Mac at 64 sample buffer size and Pro setting with no hiccups, but your mileage may vary.

 

Next time, we’ll wrap up with a look at the patch Browser, and the single strongest point in favor of M-Tron Pro IV over every other Mellotron software out there (and all of the hardware ones, too) – its incredible library of sounds. See you then!

 

mike

 

[Dr Mike Metlay]

A GODZILLION SOUNDS – AND HOW TO FIND THEM

 

Hello, everyone! I'm sorry for the delay on this last installment of my M-Tron Pro IV writeup. But here it is, and it covers a completely revamped part of the M-Tron Pro IV experience. No discussion of any M-Tron product would be complete without talking about its strongest and most unique feature: the sounds themselves.

 

As we’ve mentioned, an M-Tron Pro IV Patch consists of settings for both Layers (including the Collection and Tape Bank), the FX, and the status of the Brake and Rewind buttons. (Changing Patches doesn’t touch the Volume or Tone controls, but it does set the Pitch and A–B controls back to center.) 

 

As it comes from GForce, M-Tron Pro IV has (by my sloppy count) something like 800 patches based on some 200 factory tape banks. As you add expansion packs with more tape banks, this collection gets really huge really fast, and one of the real weak points of previous versions was how hard it was to search for exactly the right patch.

 

M-Tron deals with this directly with an all-new Patch Browser that provides a lot of ways to search your collection for exactly the right sound.

 

THE PATCH BROWSER

 

Hit the Browse button on the top of the screen (or click on the patch name) to open the Patch Load Screen:

 

 

Compared to previous versions' dropdown menus, this new Browser is a huge relief!

 

The top of the window shows information about the currently loaded patch: its name and author, the two Layers' Tape banks, notes on the sound, and its Tags.

 

Each patch can have one or more tags, which allow you to search for:

- Category: instrument grouping (flute, choir, organ, etc) or structure (mixed, rhythm, etc)

- Type: characteristics of performance (chord, looped, note run, phrase, etc)

- Timbre: sound qualities (breathy, bright, dark, resonant, sharp, etc).

 

The column browser lets you choose the Collection of sounds, then the Category, Types, and/or Timbres you desire. Since a Patch can have multiple Type and Timbre tags, search flags can be set OR or AND to create different types of filtering. For example, you can search for patches with Type = Artist Patch AND Evolving, or Timbre = Deep OR Soft OR Dark. To avoid filtering in a column, you can always choose ALL.

 

You can also search for patches by name. Note that whatever filters you have in place will restrict where the plug-in will look for results. You can quickly sidestep the filtering by starting your search name with a tilde (~).

 

The Alpha symbol represents the 50 patches that GForce feels represent the "best of" for M-Tron Pro IV as it comes from the factory, and the heart icon lets you select Favourite patches for fast searches. Patches can be sorted A to Z, Z to A, or by Alpha or Favourite.

 

Along the bottom of the window are various handy functions. You can create and load an initialized patch, choose (not create!) a random one, and audition the currently chosen patch at the pitch of your choice with a mouse click. 

 

You can also set up a Program Change map to assign a patch to a particular MIDI Program Change number via a pop-up list – just drag and drop the patch to the slot.Note that this capability is not available in the VST3 version, as this capability has beenremoved from all VST3 plug-ins. I’m not a VST3 expert, so I honestly have no idea why this was considered a good idea; I would assume there’s a new way to set up this sort of thing within the plug-in standard itself…?

 

TAPE BANK SELECT

 

If you click on either Layer label, you can open a window to select a tape bank for that Layer.

 

 

This is handy not only for creating patches from scratch, but also to easily try things like: "I really dig this layering and panning and everything that I've set up for these two different flute tape banks... what if they were choirs instead?".

 

This simplified version of the main browser lets you choose the Collection, Category, and Tag (a mixture of Type and Timbre), or search for a tape bank by name. You can also clear the current bank without selecting a new one, if you want your patch to only have one active Layer.

 

PATCH SAVE

 

When it's time to save your edited patch, you get the following window:

 

 

This is where you set the Category, one or more Types and Timbres, the patch name and author, and any notes you want to include.

 

THE SOUNDS AND TAPE BANKS

 

It's going to take you a long time to get through all of the tape banks and patches in the factory patch list when you first download M-Tron Pro IV. There are over 200 tape banks totaling over 3 GB of sounds in the base version, and for a lot of people that will support a lifetime of exploring.

 

However, there's a lot more than that to be had. M-Tron Pro has by far the most comprehensive set of tape banks of any software Mellotron... and when I say "by far", that is not hyperbole. There over 500 tape banks available to you, and you can read all about them and hear example sounds on the GForce website.

 

Expansions are grouped into products called Collections, each of which adds a number of new tape banks based around a particular instrument or sound source. Here are some highlights:

 

The Streetly Tapes are (to date) six volumes of expansion sounds gleaned from the long history of the Mellotron, as well as new sounds specifically created and edited for M-Tron Pro.

 

There are also Streetly Tapes for the Mellotron M300 Lead sounds and for the infamous SFX Console, a special tape set for the Mellotron MkII that offers hundreds of keymaps used by the BBC to provide live sound effects for radio and television broadcasts. There's everything from trains to crowds to gunfire to weather to machinery and much more... just be prepared to take a lot of notes, as the library itself is sorted by banks but each individual note's sound isn't annotated anywhere. ("Hey Mike, would you consider--?" "Maybe.")

 

At the outer reaches of the Mellotron world are sounds from competing "analog sample players" like the Mattel Optigan, Vako Orchestron, and real oddities like the Fender Piano Bass and Waddington Compute-A-Tune (some of these are available for free). There's a lot of wild stuff to choose from, and that's part of the fun of M-Tron Pro.

 

 

A FINAL THOUGHT

 

When working with M-Tron Pro in the past, I’ve heard a few Poindexters complain that there isn’t enough sound engine flexibility and potential for fine sound design here. They're probably still complaining despite all the new capabilities in version 4, but now as then, I think that completely misses the point.

 

This is a Mellotron, people! M-Tron Pro IV, like its predecessors, is meant to be played, with the sounds presented “as is” in all their original glory and no muss or fuss. You wouldn’t insist on extensive sound-mangling features in a piano or organ plug-in, and the Tron needs to be thought of the same way.

 

If you really want to take these sounds and run them through a granular synthesizer and then process the results with cross-modulation and a multi-stage loop sequencer with joystick control, there are other plug-ins where you can do that. Find some over-the-top synth workstation thingy that has a Mellotron sample library and go bananas. I have five of them, including Omnisphere, Falcon, and Synthmaster 2.9 – and I play M-Tron Pro far more than all of them combined. 

 

There's a demo version of M-Tron Pro IV if you want to give it a try. It is freely downloadable but has only the 50 Alpha patches loaded, and it's timebombed to 6 hours of use or 7 days install time, whichever expires first.

 

So what are you waiting for? Try it and fall in love with the sound of the Tron all over again.

 

mike

 

[David Emm]

Excellent work, Mike. I grab a Mellotron when I need one, but the plug is so comprehensive, its very much like a well-endowed synth. Sometimes the tweaks you can make blur the line between M-Tron and unique instruments from Klevgrand or Cherry Audio. Its safe to say its a major Key Buy winner, for old Keyboard readers. 🤓

[Dr Mike Metlay]

25 minutes ago, David Emm said:

Excellent work, Mike. I grab a Mellotron when I need one, but the plug is so comprehensive, its very much like a well-endowed synth. Sometimes the tweaks you can make blur the line between M-Tron and unique instruments from Klevgrand or Cherry Audio. Its safe to say its a major Key Buy winner, for old Keyboard readers. 🤓

I agree. Somebody once asked me if I could do an entire live show using only one plug-in, and I cited M-Tron Pro... and that was version 2.

 

mike

[Dave Bryce]

Thank you indeed, brother Mike.  Consider me a convert. 😊

 

dB

 

 

[Nowarezman]

Late to the party here...just to say that I've been a huge fan of the G-Force Mellotron instruments since they put out version one whenever that was in the foggy heretofores.  

 

I love the classic 'Tron fare like the Strawberry Fields flutes and prog Orchestral Strings and such, like everyone else.  But the big fun for me is just poking around for weirdness and oddness to lend an indescribable vibe to some track I'm composing.  The M-Tron, especially this new Pro IV,  is both immediately familiar in many ways, and also a doorway into an infinite twilight zone ranging from the ridiculous to the sublime and all points between. 

 

nat