cherry audio gx-80 Team Test: Cherry Audio GX-80

[Dr Mike Metlay]

Historical Perspective: Part 2

 

Last time, I described the world that the GX-1 was born into. Now let's talk about the instrument itself. 

 

Once again, full disclosure: much of this information was taken from my book SYNTH GEMS 1 and the associated research that went into it. I owe a great debt of thanks to keyboard guru (and proud GX-1 owner) Gordon Reid for keeping my work accurate and honest, and I'll try to condense it here without making any mistakes...

 

So what precisely was the Yamaha GX-1? Yes, it was an analog synthesizer, but it was designed to play like an organ, and that means it had features that were unlike what you'd find on any other synthesizer at the time, or (with a few notable exceptions) before or since. Many of its capabilities were utterly alien to both organists and synthesists, and taken all together in a package, they set a bar that no other synthesizer has ever reached.

 

That is not hyperbole. The GX-1 is a machine of pure myth and legend. Here's why.

 

One Tone

 

The essential sound element of the GX-1 is the Tone, a single synthesizer voice. It consists of a single VCO through two VCFs in series - highpass then lowpass - then a VCA. What's so exciting about a signal path that's the same as a Juno-60's? Read on...

 

The VCO on the GX-1 is capable of providing a simultaneous mix of up to seven different waveforms. Yes, seven. The first four are a sawtooth wave available both unfiltered and through a dedicated bandpass filter, and a pulse wave with PWM available both unfiltered and through a highpass filter. There are also a triangle wave, a noise source, and a sine wave. Oh, and each of those waveforms can have an adjustable mix of octaves and harmonics within it, just like altering organ tones with drawbars. All of these but the sine are mixable and adjustable in the VCO section; the sine bypasses the filter and is mixed in at the VCA input.

 

[Pop quiz: why would you not put the sine wave through the VCF? Answer below.]

 

That waveform mix, which few if any analog synths can match today, is then fed through the two VCFs. Unlike the CS-80 filters, which are known to be resonant 12 dB/octave designs, no one knows precisely what the GX-1's filter characteristics are, although their behavior can be (and is) modeled.

 

They are calibrated in "harmonic numbers" relative to the fundamental, with a wide range of resonance from gentle to fairly sharp (but not self-oscillating). Even so, all the service manual says about them is that they have a ten-octave range, from 25 Hz up to well beyond 20 kHz - pretty astounding, and one reason why the GX-1 sounds as open and clear as it does. These filters are not identical to the CS-80's; they are in a class by themselves. That's why the GX-80 models both, switch-selectable per rank.

 

From there, the output from the VCF is added to the sine wave from the VCO and run through the VCA. While the VCA has a conventional ADSR envelope, the VCF's invertible envelope is a bit more complex, with Initial Level, Attack Level, Attack Time, 1st Decay Time, and 2nd Decay Time. (We'll discuss this unusual and truly groundbreaking envelope, which is also featured in the CS-80, later on.)

 

Programming

 

If you count up all the waveform switches and amounts, plus the parameters for the envelope stages, you get a set of 26 parameters to control the sound of a Tone. But how do you set them? As Dan just pointed out, there are no controls for any of these parameters on the front panel!

 

Easy as pie! You hook up the GX-1 to an external programmer called the Tone Board, which has all the relevant knobs, sliders, and switches, each one numbered from 1 to 26 with a graphical layout of signal routing and envelope shapes. You then set the parameters until you get a sound you like. Of course, those settings are lost when you disconnect the Tone Board; wouldn't it be great if you could somehow save them?

 

Trivially simple! You now hook up the Tone Board to the Tone Module Setting Box, and plug in a Tone Cartridge. You then gently turn each of the Cartridge's 26 trimpots, one at a time, until the Setting Box indicates that its value matches the one on the Tone Board. You do this 26 times, unplug the Tone Cartridge, slot it into the GX-1, and you've saved all your Tone settings - in a completely analog storage system, with nary a digital microprocessor in sight! Sure it takes forever, but you can do it... and this is in 1975.

 

Many Tones

 

Okay, so this is a bit more than your usual 1-VCO/2-VCF/VCA voice. If a monophonic synth with just one of these Tones had been released in 1975, it would have been a real attention-getter, even if the parameters couldn't be saved in any way. The thing is, the GX-1 had way more than one Tone...

 

Count along with me, kids: A monophonic Solo Synthesizer with its own Tone! Upper and Lower manuals, each one with 8-voice polyphony, and each voice with two layered Tones! Pedals playing a monophonic voice that is made up of three layered Tones, two of them sharing the same program settings! 1 + 8 (x2) + 8 (x2) + 3 = 36 Tones playing up to 18 voices at once... and it was released in a year where nobody had ever heard a synthesizer play chords before. Think about that for a second!

 

And by the way, all of those Tones can be different, because the GX-1 holds a whopping 70 Tone Cartridges, which can be assigned to various manuals with a set of buttons right above the Upper Manual, which when all the routing options are taken into account, offer a whopping 175 possible combinations of Tones. Still holding on there, kids?

 

Playability and Power

 

The pairs of Tones within the manuals can be detuned from one another, with a different amount of detuning for the Upper, Lower, and Pedals. These tuning controls are hidden in a slide-out drawer under the Lower manual. In addition, each manual has its own Brilliance and Resonance controls for per-manual bandpass filters on top of everything else!

 

Want more? The Upper manual can modulate VCO pitch and VCF cutoff and/or resonance by wiggling the keys from side to side; the Solo manual has velocity, pressure, and side to side control, and the ribbon controller above it is calibrated so it has the same range as the manual, so you can slide pitches from key to key.

 

Spring reverb with override for an external stereo effects loop? Check.

Side-to-side knee controller bar to change the variable sustain for each manual, polyphonic portamento for the Upper manual, and more? Check.

Foot pedal and five-function toe switch? Check.

Crappy preset-based internal rhythm machine? Check.

Audio outputs? Ch... wait. Where are they?!

 

The GX-1 has only one audio output: a multipin cable that's designed to connect to the TX-II speaker cabinet, a monstrous 300-pound octagonal speaker tower with nine drivers (15" woofer, four 8" 'squawkers', and four 2" tweeters) firing in a wide arc and powered by dual 120W tube amplifiers. The cable can support up to three of these towers, and assign the manuals in various ways to spread out their sound. 720 Watts of power through 27 drivers including three 15" woofers - the sound is indescribable, capable of filling a cathedral without breaking a sweat. (Which is what it was designed to do. Organ, remember?)

 

Put it all together and you're talking about a synth with three keyboards and 36 voice circuits, each one equivalent to a monophonic analog synthesizer, plus all the manual-level and global circuitry, plus 70 cartridges full of analog components, altogether weighing well over 300 kilograms. Add in the custom stand, pedalboard, and three 141-kg speaker towers, and you have a package with the easily portable total weight of roughly 0.8 metric tons, which can't be tilted when you move it or it will be damaged or destroyed. And even if you could find one, it would set you back probably a quarter of a million dollars in today's market.

 

What about building a modern version of the GX-1 using modern tech? Heh. People have been trying to build a new version of the much simpler CS-80 in hardware for years, and a few people have come close but no cigar... and the circuitry involved in re-creating the GX-1 is many times more complex. Even a major synth maker with access to the necessary tools and resources would never take on such a monumental task - how many would they sell? Would they ever recoup the costs? Aych Ee Ell Ell NO they wouldn't.

 

And why would they bother? No matter how much they spent, everyone would say it didn't sound like the original, and they knew that because they heard the original in a YouTube video of somebody poking at one in a museum and recording it with a cell phone. (Siddown, Poindexter. Yes, I'm talking about you. Suck it up.)

 

And that, dear readers, is why it is so amazingly, brain-meltingly cool that several of the GX-1's unique features have been integrated into the GX-80 software, starting with the relatively familiar CS-80 voice architecture and taking it to unheard-of new places. (Sorry, but Cherry Audio hasn't figured out how to let you control the plug-in with your knee. Yet.)

 

Now it's time for you to scroll back to Jerry's excellent overview of the ranks, to see (among many other things) how the GX-80's layout differs from the CS-80's and how the added GX-1 features enter the equation. Go on, off you go now! Scoot!

 

[Pop quiz answer: because it's pointless. A sine wave has a single frequency; all a filter will do is turn it up or down as the cutoff frequency goes past the sine frequency. So why not just bypass the filter and give it its own volume slider? Hurr durr!  ]
 

[Dr Mike Metlay]

1 hour ago, mate stubb said:

The manual wasn't entirely clear - can you get HPF pulse without regular pulse and HPF saw without regular saw?

HPF pulse and BPF (not HPF) saw are available on their own. Just switch off the pulse and saw waves with the two black switches.

 

Here's an example of front panel settings that give you a combo of filtered waves with no raw waves:

[MRBarton]

A couple tiny additions/corrections to the Doctor's excellent review of the GX-1.  First, there is nothing mysterious or especially unique about the filter envelope.  It is an ADSR envelope like any other.  It is just parameterized differently.  On most synths it takes 5 controls; A, D, S, R, and envelope amount to control the filter.  On the GX/CS instruments it also takes 5 controls; IL, AL, A, D, and R.  These controls contain the same information and accomplish the identical task, but in a slightly different way.  You can create AD, AR, and ADSR envelopes just like with a standard envgen.  A quick stroll through the GX-80 manual will fill you in on all you need to know.

 

On the GX-1, the sine wave was included back in the oscillator section.  When the CS-80 was made, it was decided to move it post-filter where we have decided to keep it because we think that move was a good idea.  And yes, you can filter a sine wave -- attenuating is filtering.

 

There is no global bandpass filter associated with the BRILLIANCE and RESONANCE performance controls.  They act as biases for the filters contained in all the voices and affect both ranks.  The BRILL control can add or subtract from the filter cutoffs and the RESON control only adds to the resonances.  Therefore the default positions for these sliders are BRILL in the middle, RESON all the way up (minimum).  Remember, moving the BRILL control affects both the HP and LP filters, but not equally.  In general, the HP moves less than the LP.  For example, the envelope moves the HP half as much as the LP.  This has two benefits.  First, it opens up the passband between the filters allowing for a fuller tone, and second, by not having the HP creep up as high, you don't lose as much low end. 

 

--mb

[mate stubb]

Gordon Reid has been mentioned a couple of times. I thought I'd provide a link to his excellent adventure tale of obtaining his GX-1 and having it shipped half way across the world.

 

https://www.soundonsound.com/reviews/yamaha-gx1-synthesizer-part-1

 

And a brief quote about the first time he turned it on:

 

"I can still remember my overriding emotion as I turned the thing on: sheer, abject terror. And, for a few seconds, my worst fears were realised. Then the valve amps warmed up, the start‑up mute circuit disengaged, and I pressed a key.

I suspect that everyone within a hundred‑mile radius of Cambridge heard that first note. With the speakers' internal amps unwittingly set to maximum and the main output volume full up on the GX1 itself, I imagine that its foghorn blast raised the dead right across the East of England."

[jerrythek]

Timwat posted this over in the Keyboard Corner... it's the wonderful Tom Szakaly, known for his ELP tribute band Noddy's Puncture. Tom was close friends with Keith, who shared a lot of scores, performance tips and such with him, and even sat in on one of his pub gigs. And Tom lent his Hammond L-100 to Keith on a number of occasions. I met Tom backstage at the Manticore Hall duo show by Keith and Greg back at the Westbury Fair on Long Island NY. He knows his way around Keith's music, for sure. Wish he had the front panel down...

 

[jerrythek]

And I'm not sure if this helps or hurts the cause... but I've never seen such a clear demo of the GX-1 before:

GX-1 demo 1975

 

 

[Dave Bryce]

Performance Controls Overview

 

 

 

Here we find the heart of the real-time controls over the Ranks. They affect whichever LAYER (pair of Ranks - I/II or III/IV) is currently selected.  

 

This is the home of the Paddle switches, which - in an effort to accurately recreate the feel of working with a Yamaha organ - operate backwards from switches and sliders on most synths: up is OFF, and down is ON.  

 

Let’s go over them from the left-hand side of the instrument to the right.

 

Tuning

 

The MASTER PITCH knob’s function is pretty obvious – it adjusts the instrument’s overall pitch, up or down a semi-tone. 

 

Unlike the hardware CS-80, which only offers the ability to detune Rank II away from Rank I, the DETUNE CH I/II Paddles deliver the ability to independently detune either rank in a Layer away from center in either direction, +/- a semi-tone, with center being the null position.  Muuuuch more flexible and conventional – it's generally more desirable to have the option of being able to individually detune each Rank away from center rather than only being able to detune the second Rank as an offset.  This works on Ranks I/II, or III/IV when either SPLIT or DUAL mode is selected in the GLOBAL CONTROLS section.

 

Ring Modulator 

 

 

This section and a large part of its functionality has already been deeply covered in a few earlier posts in this review. This one by Mark Barton is particularly informative.

 

The general concept is that a Ring Modulator provides the sum and difference frequencies of two combined audio sources, eliminating the common frequencies from the signal.  Ring Mod combines Ranks I/II with its own sine oscillator, or III/IV if SPLIT or DUAL are engaged. 

 

A simple Attack/Decay envelope offers control over the Ring Mod speed rise/fall based on SPEED parameter, with the envelope amount controlled by the DEPTH paddle and the overall Ring Mod level handled by the MOD control.  

 

Note – this function operates monophonically, as there’s only one ring mod per layer. Consequently, it behaves similarly to percussion on a Hammond - it triggers when you press a key, but only retriggers after all the keys are released.

   

You can also choose not to use the Ring Mod’s envelope controls by leaving the Depth paddle zeroed (all the way up) and using the MOD paddle to set the level.

 

Sub Oscillator 

 

 

The Sub Oscillator is essentially the LFO – it produces sub-audio range signals intended to be used for modulation, and affects both currently active ranks in a Layer (I/II or III/IV) equally.

 

LFO waveform selection is handled by the paddle oddly labeled FUNCTION.   A comprehensive set of options include sine, sawtooth, inverted sawtooth, square, sample and hold, and noise.

 

The MOD WHEEL rocker switch toggles the LFO…ummm, I mean Sub Oscillator from just being on with the effects being immediately apparent when you route it to VCO/VCF/VCA in any combination using the relevant sliders, or being controlled by an external Mod Wheel.  The rate is adjusted using the SPEED paddle; or, using the SYNC rocker switch, can be locked to a host tempo (such as a DAW) or to the current tempo in the top menu bar when using the standalone version.  

 

The LED at the top of this section flashes to indicate current modulation rate. 

 

Feet 

 

 

The coarse pitch range for each oscillator is set up a bit unusually for Ranks I/II (or III/IV if using SPLIT/DUAL mode) using traditional organ footage settings of 16', 8', 5 1/3', 4', 2 2/3' and 2'.

 

There are two additional footage settings (3 1/5' and 2 2/7') lifted from the GX-1.  I fully admit that I’m not sure how to best use those last two…yet. 🤔

 

Tone Selector and Mix

 

 

The hardware CS-80 was one of the first synths to offer presets and user slots.  Each Rank had its own set of 11 presets, with the Rank I and II presets containing slight variations (e.g. buttons 3 and 4 in the Rank I row are home to one BRASS preset and one FLUTE preset respectively, where the same two buttons for the Rank II row are home to two different BRASS presets).  

 

The CS-80 also had four USER memories, controlled by four sets of tiny sliders replicating the Rank parameters and concealed behind a hinged metal door in the synth’s upper left-hand corner. The Tone Selector’s backlit buttons navigated the factory and user presets as well as accessing the current position of the front panel Rank parameter sliders using the PANEL buttons.

 

The GX-80 improved on the original layout by giving the illuminated buttons dual functionality.  The 22 PRESET buttons remain in place.  Clicking any of the PRESET buttons causes the relevant Rank parameters to jump to the current setting for that preset, and shuts off the PANEL button per Rank. Editing a PRESET will cause the relevant Rank's PANEL button to relight.

 

However, one of the other buttons (USER) toggles the 22 rank-specific presets to 22 rank-specific User locations (top row for Ranks I and III, bottom row for Ranks II and IV, like so:

 

 

The buttons that are dark in the above screen shot do not have any user Ranks saved to those slots.

 

Note: the settings stored in the USER Bank buttons stay in memory across multiple instances, and are even remembered when the GX-80 is “powered down”.

 

Another button (UTIL) accesses advanced management functions such as the ability to easily copy, swap and reset Rank settings. 

 

 

Calling up the related drop-down menu is the only function I could find in this section that required right-clicking to access it. 

 

The MIX slider located to the right-hand side of the Tone Selector section is used to adjust the volume balance between either Ranks I and II or III and IV.

 

Brilliance and Resonance

 

 

These two controls are among the first ones on the GX-80 to grab for a quick global tweak of a program.  They control both active ranks (I/II or III/IV) simultaneously.

 

BRILLIANCE is kind of like a master buss EQ, affecting both the High and Low Pass filters on both active ranks, and - you guessed it - the RESONANCE control is for tweaking the resonance for HPF and LPF on both active Ranks.

 

Here’s another post by Mark Barton that dives deeper into these controls.

 

Touch Response 

 

 

This section adjusts how the GX-80 can respond to velocity and aftertouch.

 

Increasing the PITCH BEND paddle’s value makes notes bend up into the desired pitch when velocity is employed, which is a fabulously expressive effect.  Harder velocities lower the initial pitch, although the speed of the bend up does not change.  

 

The SUB OSC AFTER sliders allow modulation of the LFO…sorry again, Sub Oscillator (😁) via aftertouch with the SPEED paddle controlling the rate, VCO paddle influencing pitch mod depth and VCF paddle affecting both the High and Low Pass filters.

  

Note: the VCO and VCF paddles in this section add on to the settings of the related paddles in the Sub Oscillator section covered previously in this post.

 

Keyboard Control 

 

 

These controls fine-tune the response of the High and Low Pass filter cutoff frequencies and the VCA level depending on the range of notes being played.  This section is set up for maximum flexibility - the center of the keyboard is the most neutral, with independent controls for higher and lower notes.  

 

Like some of the other controls in this section (such as DETUNE), these controls are bi-polar (center is 0), with the  BRILLIANCE LOW and LEVEL LOW respectively opening/closing the filters and increasing/decreasing the amplitude more the lower you play on the keyboard controller, while BRILLIANCE HIGH and LEVEL HIGH respectively open/close the filters and raise/lower the amplitude more the higher you play.  

 

Note: the LEVEL paddles boost the amplitude ~6dB when increased, or attenuate it ~40dB when decreased.

 

 

Master Controls

 

 

Here’s where you apply the finishing touches.

 

As mentioned earlier, LAYER refers to the currently selected combination of either Ranks I/II or III/IV. The LAYER LEVEL slider sets the output volume for the finished sound, allowing leveling of program banks so that there aren’t any volume imbalances in DUAL or SPLIT programs, or abrupt jumps in volume when changing from one program to another. 

 

The MASTER VOLUME is, of course, the main volume knob. 

 

The LIMITER is set to kick in just before clipping occurs, providing 20dB of headroom in order to transparently avoid clipping/distortion.  It has a very fast attack and a 200ms release, a threshold of -2dB and a 10:1 compression ratio.  

 

The output level LED ladder is also an excellent indicator that you may be overloading the synth’s output…although, depending on the type of sound you’re after, that may be a desired effect. 

 

dB

 

[MRBarton]

Nicely done Dave.  Just my usual couple of clarifications here.

 

First, to not use the envelope in the ring modulator, it's the DEPTH control you want to zero out, not the ATTACK and DECAY.

Second, the four KEYBOARD CONTROL paddles are bipolar in nature (oh dear!).  Pulling the LEVEL paddle down will result in a ~6db boost at the farthest key from center, but pushing it up results in ~40db of attenuation.  This is usually the preferred direction to go.  Ever have a patch that sounded great in the middle of the keyboard, but took your head off when you played up high?  This is what these paddles are for.  Likewise, you can control the tone contour across the keyboard with the two BRILL sliders.

 

Here's a fantastic thing you can do with these paddles that came to me in a flash when I was writing these controls up.  If you set the  paddles in opposite ways on the two layers, you can smoothly crossfade from one sound to another as you play up the keyboard!  No hard split point needed and it works really well.  It's really liberating to play anything you want and not have to worry about where that darn split point is.

 

IMPORTANT TO KNOW:

Here's how to use the level keyboard dynamics controls correctly.  These are the controls at the far right of each rank.  There is a misconception that the LEVEL control just to the right of the VCA envelope is the volume control for that rank.  Although it can act as such, that is not its purpose.  To adjust the level for the rank, use the two mixing controls, VCF LEVEL and SINE LEVEL to the left of the VCA.  (This was an endless source of confusion for me as well.  Why are there so many level controls???)

 

There are actually two VCAs in series at the output of each rank.  One controls keyboard volume dynamics and the other is for the envelope.  The keyboard dynamics VCA is fed with 3 control voltages which are summed.  They are the LEVEL control which is just variable DC, INIT LEVEL which is velocity, and AFTER LEVEL which is pressure.  At least one of these needs to be turned up to hear anything.  If you only use the LEVEL control, it would seem that this slider controls volume because it does by opening the VCA.  However, if you turn up INIT LEVEL instead, leaving LEVEL at zero, you will get full range velocity dynamics.  If you only turn up AFTER LEVEL, then pressure will take the volume from nothing to full.  The LEVEL control sets a fixed minimum volume when using the other two.  To get more dynamic effect, turn LEVEL down while turning the others up.  Even with LEVEL turned up full, there is a little headroom left for velocity and pressure to take things up a bit further.  The two BRILLIANCE control sliders also have a fixed control -- the cutoff sliders themselves.

 

I kept the 4th VCA control voltage a secret up to now for the sake of clarity.  It comes from the SUB OSCILLATOR VCA paddle.

 

I hope that explanation was clear.  Any questions will be cheerfully answered.

 

--mb

 

[Dave Bryce]

Thank you so much for the clarifications, brother Mark.  I fixed both. 😎

 

It’s a privilege and a pleasure to have you helping us on this review! We really appreciate you taking the time. 👊☺️

 

dB

[jerrythek]

12 hours ago, Dave Bryce said:

The coarse pitch range for each oscillator is set up a bit unusually for Ranks I/II (or III/IV if using SPLIT/DUAL mode) using traditional organ footage settings of 16', 8', 5 1/3', 4', 2 2/3' and 2'.

 

There are two additional footage settings (3 1/5' and 2 2/7') lifted from the GX-1.  I fully admit that I’m not sure how to best use those last two…yet. 🤔

 

For those of us that are drawbar-challenged, these work out to be:

16' - an octave below the note played

8' -unison

5 1/3' - a fifth above unison

4' - an octave above unison

2 2/3' - a fifth above the octave

2' - another octave higher, or 2 octaves above the unison

 

3 1/5' - a major third above the octave

2 2/7' - the flatted/minor seventh above the octave

[AnotherScott]

5 hours ago, MRBarton said:

Here's a fantastic thing you can do with these paddles that came to me in a flash when I was writing these controls up.  If you set the  paddles in opposite ways on the two layers, you can smoothly crossfade from one sound to another as you play up the keyboard!  No hard split point needed and it works really well.  It's really liberating to play anything you want and not have to worry about where that darn split point is.

 

This sounds similar to the slope velocity crossfading parameter in Korg workstations, or the crossfading feature of the Nord Stage 3 and Electro 6 (which doesn't stop people from complaining that you can't place the split points at any key you want!).

[Anderton]

GX-80 Meets Mid-Side Processing

 

...and here's something to cleanse the palate before our next onslaught of cool GX-80 stuff. 

 

The GX-80 sounds huge, but mid-side processing can make it huger by altering the balance of the mid and sides. The audio example, which does very basic mid-side processing, highlights the difference.

 

The first half is the Au Revoir Yellow Brick Road preset. The second half extracts the mid and sides, and boosts the sides somewhat. If you listen over stereo, and especially with headphones, you'll hear the preset become bigger and more animated.

 

 

Extracting the mid and sides isn't difficult. This image shows how it's done in Studio One, but pretty much any DAW can do the same thing. You can also use a Mid-Side encoder like the Voxengo MSED, but the advantage of extracting the mid and sides to separate channels is then you can process them individually. I did no processing in the audio example just to show what "naked" mid-side processing can sound like, but doing tricks like adding delay to the mid and reverb to the sides...well, I'll let you find out for yourself

 

(image courtesy Sweetwater Publishing, from the book Max Your Mix)

 

Here's the explanation:

 

• The GX-80 has two pre-fader sends going to two buses, Mids and Sides.
• The Mids channel simply pans the left and right channels to center. I'm using the Dual Pan plug-in in Studio One because it has a choice of pan laws. Ideally, you want to use the linear, 0.0 pan law - not the usual one that drops the center by -3 dB RMS. Then, you get the center-channel buildup that contrasts the mid more with the sides.
• The Sides channel inverts the right channel (in Studio One, this uses the Mixtool; in Pro Tools, it would be the trim plug-in). Then, it sums the left and right channels together with another Dual Pan plug-in. So, the center cancels, because the right channel is out of phase. Then, the signal has its right channel re-flipped. So, the sides now have the correct phase relationship, but the center is gone.

You can vary the blend of the mid and sides, as well as include processors. Short delays on the mid or sides work well, and the stereo image still collapes to mono properly.

 

Pro Tools note: Re the sides, after you invert the right channel and sum it to mono, the channel turns to mono. So, you have to convert it back to stereo before you can invert the right channel a second time. Any mono-to-stereo plug-in will do the job, but I use the Auto Panner set to zero width.

Studio One note: You can also use the MS Transform option in both Mixtools. Set the Dual Pan between them to Right Input only, and set the right pan control full right. The reason why I used the phase flipping was because this technique is more applicable to other DAWs.

[Dr Mike Metlay]

On 11/29/2022 at 2:55 AM, MRBarton said:

A couple tiny additions/corrections to the Doctor's excellent review of the GX-1. 

Allow me to add my voice of appreciation for all of your background on this, Mark. You've made sure we keep things as accurate as we can and I always appreciate that!

 

On 11/29/2022 at 2:55 AM, MRBarton said:

First, there is nothing mysterious or especially unique about the filter envelope.  It is an ADSR envelope like any other.  It is just parameterized differently.  On most synths it takes 5 controls; A, D, S, R, and envelope amount to control the filter.  On the GX/CS instruments it also takes 5 controls; IL, AL, A, D, and R.  These controls contain the same information and accomplish the identical task, but in a slightly different way.  You can create AD, AR, and ADSR envelopes just like with a standard envgen.  A quick stroll through the GX-80 manual will fill you in on all you need to know.

I would have to courteously disagree here. Yamaha deslgned that filter for a reason... if the controls contain the same information and accomplish the identical task, then why did Yamaha create it when the VCA has a perfectly good ADSR? The "slightly different way" has real significance for sound design, which is why I plan to talk about it when I cover the filters.

 

On 11/29/2022 at 2:55 AM, MRBarton said:

On the GX-1, the sine wave was included back in the oscillator section.  When the CS-80 was made, it was decided to move it post-filter where we have decided to keep it because we think that move was a good idea.  And yes, you can filter a sine wave -- attenuating is filtering.

Well, the Kindly Pedant said pedantically yet kindly, that IS kinda what I said... the sine is attenuated when the filter cutoff passes by its frequency. 😇

 

As for the point about the sine wave placement: We're both saying the same thing. Your wording is inspired by the CS-80's front panel controls...

 

...whereas mine goes back to the source:

 

Ya pays yer money, ya takes yer choice.

 

 

On 11/29/2022 at 2:55 AM, MRBarton said:

There is no global bandpass filter associated with the BRILLIANCE and RESONANCE performance controls.  They act as biases for the filters contained in all the voices and affect both ranks.  The BRILL control can add or subtract from the filter cutoffs and the RESON control only adds to the resonances.  Therefore the default positions for these sliders are BRILL in the middle, RESON all the way up (minimum).  Remember, moving the BRILL control affects both the HP and LP filters, but not equally.  In general, the HP moves less than the LP.  For example, the envelope moves the HP half as much as the LP.  This has two benefits.  First, it opens up the passband between the filters allowing for a fuller tone, and second, by not having the HP creep up as high, you don't lose as much low end. 

Thank you so much for this clarification! This is actually how I originally thought it worked; I misread something Gordon Reid wrote on the subject and that's how my misstatement came around. I appreciate the followup!

 

mike

 

[Dr Mike Metlay]

On 11/25/2022 at 6:19 PM, JazzPiano88 said:

Keith playing the GX1:

 

 

 

 

Has anyone else noticed that whether it's Greg's bass flourishes, Carl's percussion accents, or the many different cool things Keith does on the GX-1, the camera chosen in the edit is always looking somewhere else at the time? It's maddening!

 

mike

 

[Dr Mike Metlay]

On 11/30/2022 at 9:54 AM, jerrythek said:

 

For those of us that are drawbar-challenged, these work out to be:

16' - an octave below the note played

8' -unison

5 1/3' - a fifth above unison

4' - an octave above unison

2 2/3' - a fifth above the octave

2' - another octave higher, or 2 octaves above the unison

 

3 1/5' - a major third above the octave

2 2/7' - the flatted/minor seventh above the octave

 

Yamaha laid these out – and the calibration for the VCF as well – in Harmonic Numbers, meaning harmonics relative to the fundamental. As discussed in Gordon Reid's excellent SOS article, each of the GX-1's manuals had the equivalent of six drawbars (what Yamaha called Over Tone sliders). However, as on many other organs, the selection of which harmonics were available was different for each manual. These ranged from 32' for the Pedals all the way up to 2' for the other manuals. (We'll ignore the fact that the Solo synthesizer had not one but two drawbars for 128'.)

 

Jerry's list above includes the six footages that were available on the CS-80, which are Harmonic Numbers 1, 2, 3, 4, 6, and 8. The next two are only available on the GX-1. While Hammonds don't have a drawbar for 3 1/5 (Harmonic Number 5), they do have a 1 3/5 drawbar, which is the corresponding harmonic one octave up.

 

I believe that 2 2/7, Harmonic Number 7, is unique to the GX-1. It could be mixed into Rank II of the Upper and/or Lower manuals. I somewhat suspect that Yamaha did this just because they could; as Good Sir Dave has pointed out, one needs to put careful thought into where one would throw these in...

 

mike

[MRBarton]

 

8 minutes ago, Dr Mike Metlay said:

On 11/29/2022 at 1:55 AM, MRBarton said:

First, there is nothing mysterious or especially unique about the filter envelope.  It is an ADSR envelope like any other.  It is just parameterized differently.  On most synths it takes 5 controls; A, D, S, R, and envelope amount to control the filter.  On the GX/CS instruments it also takes 5 controls; IL, AL, A, D, and R.  These controls contain the same information and accomplish the identical task, but in a slightly different way.  You can create AD, AR, and ADSR envelopes just like with a standard envgen.  A quick stroll through the GX-80 manual will fill you in on all you need to know.

I would have to courteously disagree here. Yamaha deslgned that filter for a reason... if the controls contain the same information and accomplish the identical task, then why did Yamaha create it when the VCA has a perfectly good ADSR? The "slightly different way" has real significance for sound design, which is why I plan to talk about it when I cover the filters.

 

I'm going to jump the gun before you write more to agree and courteously disagree with you at the same time.  Yes, Yamaha did design that filter envelope that particular way for a very good reason, but I will stand by my claim that the 5 controls convey the same information as a "normal" ADSR+amount system.  Both designs control the AD&R timing identically, so we can ignore those.  The IL (initial level) and AL (attack level) control the envelope height which is usually done with the single amount control.  Therefore, both systems do convey the same information and accomplish the same task.

 

The genius part of the Yamaha design is that the sustain level never moves and is always at zero (therefore no need for a sustain control).  This is the envelope phase I refer to as the singing tone, the portion of the envelope where sustained notes spend the most time.  With a conventional ADSR+amount system, when you raise or lower the amount, you alter your singing tone because the sustain level moves with the overall height of the envelope.  You then need to restore it by moving the cutoff control in the opposite direction.  With the Yamaha envelope, this does not occur.  You set your singing tone with the cutoff control and then you are free to bring in and adjust your envelope however you like without the singing tone ever being altered.  It's really very clever, and once you wrap your head around the way it works, using it becomes second nature.  Yamaha could have just as easily put conventional ADSR+amount controls on there and the sounds would be the same, but they thought they had a better idea.  I think they did.

 

--mb

[jerrythek]

8 hours ago, Dr Mike Metlay said:

Jerry's list above includes the six footages that were available on the CS-80, which are Harmonic Numbers 1, 2, 3, 4, 6, and 8. The next two are only available on the GX-1. While Hammonds don't have a drawbar for 3 1/5 (Harmonic Number 5), they do have a 1 3/5 drawbar, which is the corresponding harmonic one octave up.

 

I believe that 2 2/7, Harmonic Number 7, is unique to the GX-1. It could be mixed into Rank II of the Upper and/or Lower manuals. I somewhat suspect that Yamaha did this just because they could; as Good Sir Dave has pointed out, one needs to put careful thought into where one would throw these in...

 

mike

Dave and I were discussing this offline, and I'll share my view of this. Overtones are just a part of what defines the timbre of a waveform, and instrument. I think too often people look at the harmonic and think a chord, or harmony, and wonder how to use it. I think of them as tools for creating timbre, I don't focus too much on the implied chord tone, or chord quality they define. So this harmonic does not mean you are only making a one-finger dominant seventh chord. It's just another color, a tool in the toolkit. A Rank set to this footage and mixed way back in a sound could add some intriguing "sparkle" to a sound, or an element of discord. I don't worry about it too much.

 

As another example, when Korg made the 2nd generation CX-3, we developed (they developed, it was not my idea!) an EX Mode for the drawbars which added 4 additional higher harmonics to the drawbar range, and 4 additional choices for the tuning of the percussion.  If I had to describe what we were able to create with them I would say that an additional "glassy sheen", or "exciter" aspect could be added to the sound. It had to be used judiciously, of course. But my general mantra is: if it sounds good, do it!

 

Jerry

[Anderton]

9 hours ago, MRBarton said:

Yamaha could have just as easily put conventional ADSR+amount controls on there and the sounds would be the same, but they thought they had a better idea.  I think they did.

 

I finally understand the thought process behind the envelope, thanks much!

[MRBarton]

4 hours ago, Anderton said:

13 hours ago, MRBarton said:

Yamaha could have just as easily put conventional ADSR+amount controls on there and the sounds would be the same, but they thought they had a better idea.  I think they did.

 

I finally understand the thought process behind the envelope, thanks much!

 

You're very welcome.  Mind you, this is just my speculative thought process behind their thought process.  Who knows what they were really thinkin'?

[Adi James]

I’ve been a lurker here, but would like to ask whether an NKS patch library exists for the GX-80 or if Cherry are considering adding NKS support? 
 

Such a beast demands a more tactile experience than mouse on screen, so it would be wonderful if NKS was available.

[KuruPrionz]

6 hours ago, Adi James said:

I’ve been a lurker here, but would like to ask whether an NKS patch library exists for the GX-80 or if Cherry are considering adding NKS support? 
 

Such a beast demands a more tactile experience than mouse on screen, so it would be wonderful if NKS was available.

A MIDI controller should provide that "hands on" experience and allow you to change tones on the fly. See above, some posters relate their experiences with MIDI controllers. 

[Dave Bryce]

Soooo…

 

How many of you have been writing programs for the GX-80 since you got it?  I know I’ve got several that I quite like.

 

It’d be way cool if we could get a bunch of programs from the MPN community, make a bank of them, and offer them up for free in the PRESETS section of MPN’s new DOWNLOADS area.  

 

If you’ve got any that you’d like to submit for that, please PM me. 

 

Thx!

 

dB

[David Emm]

15 minutes ago, Dave Bryce said:

 

It’d be way cool if we could get a bunch of programs from the MPN community, make a bank of them, and offer them up for free in the PRESETS section of MPN’s new DOWNLOADS area.  

 

 

Are you kidding? I'm not even through my first walkthrough of the 1000 presets! 🤪 I keep getting diverted by the Awesome. Its not the synth for everything, but it excels at its specialties beyond the same test of other instruments. Its not unlike exploring my first grand piano. Mesmerizing.

 

A bank of KC-derived patches sounds nice, but I'm skeptical, in that a cello doesn't need an added patch set. This thing is the synth counterpart. Sure, I'm taking note of the sudden golden beauties n' such, but loosely speaking, I'm coming to decide that it has about 20 different sounds that define it. Everything else is real-time ribbon tweaking, paddle nudging, etc. There's a creamy center, whether you're tweaking a brass hybrid or that great harmonica patch.

 

So I doubt I could add much when I'm still reading the outstanding tutorials and trying to figure out a few alien parameters. Its hard to polish perfection. This could become a diet aid, because you don't want to stop and eat.    

[EricP1954]

On 11/29/2022 at 6:00 PM, jerrythek said:

Timwat posted this over in the Keyboard Corner... it's the wonderful Tom Szakaly, known for his ELP tribute band Noddy's Puncture. Tom was close friends with Keith, who shared a lot of scores, performance tips and such with him, and even sat in on one of his pub gigs. And Tom lent his Hammond L-100 to Keith on a number of occasions. I met Tom backstage at the Manticore Hall duo show by Keith and Greg back at the Westbury Fair on Long Island NY. He knows his way around Keith's music, for sure. Wish he had the front panel down...

 

Just curious...is there a parameter or setting on the GX-80 that emulates the volume modulation effect that speeds up in the introl (at 0:24 and 0:52)?

[mate stubb]

46 minutes ago, EricP1954 said:

Just curious...is there a parameter or setting on the GX-80 that emulates the volume modulation effect that speeds up in the introl (at 0:24 and 0:52)?

 

I'm sure it can. It's LFO modulation of the filter, with LFO rate being controlled by (I believe) key pressure. You can set that up in the Touch Response section of the performance section.

[Nathanael_I]

A bit late to the party, but I finally fired it up. Truly excellent. Playing this with the Osmose is going to be exquisite, I can tell. Several years ago I added MIDI to an old pipe organ pedalboard. It’s in storage right now, but I made it to do the GX-1 thing (not knowing that it even existed). But it did make me think, this must be the instrument for that pedalboard!  For the curious, those are real pipe organ quality expression pedals that output MIDI. One has a side lever that acts as sustain. I think there’s 20 toe pistons. Again, high quality organ parts connected to MIDI scanning boards. It’s big and heavy!

 

 

[KuruPrionz]

55 minutes ago, Nathanael_I said:

A bit late to the party, but I finally fired it up. Truly excellent. Playing this with the Osmose is going to be exquisite, I can tell. Several years ago I added MIDI to an old pipe organ pedalboard. It’s in storage right now, but I made it to do the GX-1 thing (not knowing that it even existed). But it did make me think, this must be the instrument for that pedalboard!  For the curious, those are real pipe organ quality expression pedals that output MIDI. One has a side lever that acts as sustain. I think there’s 20 toe pistons. Again, high quality organ parts connected to MIDI scanning boards. It’s big and heavy!

 

 

That is magnificent madness!!! 

[Nathanael_I]

2 hours ago, KuruPrionz said:

That is magnificent madness!!! 

Oh yes!  It has always made sense to me that an organ console is the most appropriate control surface for synthesizers. Only now they would be poly-AT. When I had the Vax-77 from Infinite Response, I was thinking of getting a second. Nothing is more evolved for playing polyphonic keyboards with patch changes than an organ console. They just need to be touch sensitive and as expressive as possible!  I wrote up a whole logic/switching layer in Max to process the MIDI and implement coupler logic. Stuff that took a room full of mechanism is easy in software.  If you want a trip to another musical universe, look up Hauptwork and “virtual pipe organs”.   Using this kind of thing for synths just seems obvious to me. But then, that may be exactly what you are getting at!  
 

To bring it back on topic, The GX-80 has very useful registration by footage, making it easy to simulate mixture ranks, etc. For anyone used to pipe organ specifications, it’s quite easy to follow. I was only one year old when the GX-1 came out, but I’d so have wanted one most of my life!  (I’d still like one).  The GX-80 is a very grand, harmonically rich and big sounding synth.  Putting it through my big subs seems very, very worthwhile…. Super glad to have this one. 

[David Emm]

18 hours ago, Nathanael_I said:

 

 >> It has always made sense to me that an organ console is the most appropriate control surface for synthesizers. Only now they would be poly-AT. When I had the Vax-77 from Infinite Response, I was thinking of getting a second. Nothing is more evolved for playing polyphonic keyboards with patch changes than an organ console.

 

I heartily second your comments. Its not the absolute real-world solution due to space and weight considerations, but as a dream control surface, yeah. A pipe organ is a gigantic octopus that requires some training to properly engage. Its like the similar planning you do with a synth stack, because it IS one, in a sense.   

 

 >> If you want a trip to another musical universe, look up Hauptwork and “virtual pipe organs”. Using this kind of thing for synths just seems obvious to me. But then, that may be exactly what you are getting at!  
 
The Hauptwerk is the gold standard, although notables such as Modartt participate with their worthy Organteq. The idea feels natural to me, but it was also the Vangelis solution, with his own custom version of stops and pedals. I like being ITB exactly *because* its feels pipe-organ-ish to use each track as another rank of pipes.

 

BTW, the Hauptwerk is now sold under a subscription plan from $12.99/mo., up to the major Perpetual licenses @ typically pro prices. Likewise, they offer a hefty number of models to choose from, similar to Pianoteq's range of pianos. There are large and small options, from numerous countries. Sweet!

 

https://www.hauptwerk.com/

 

 >> To bring it back on topic, The GX-80 has very useful registration by footage, making it easy to simulate mixture ranks, etc. For anyone used to pipe organ specifications, it’s quite easy to follow.

 

Not hard to see, as its the giant mutant offspring of the Electone line. I believe I played one of those which featured a small touch strip made of little rollers. Some design aspects came from odd early places.   

 

 >> I was only one year old when the GX-1 came out, but I’d so have wanted one most of my life!  (I’d still like one).

 

I dunno.... its a magnificent beast, but the more I explore the GX-80, the happier I am not to be faced with the real-world issues of a giant vintage anything. Your pedals are the best stopgap I've seen. I suspect you know what a ground wire is, so you probably won't blow yourself through a wall, as seen in "Back To The Future."

 

>> The GX-80 is a very grand, harmonically rich and big sounding synth.  Putting it through my big subs seems very, very worthwhile…. Super glad to have this one.

 

I have a fairly modest bass bin, but when I hit one of those giant layered mono basses that goes BWOMP!, my dog came in and just stared at me for a minute. Most likely translation: "Will you stop that crap??" Fair enough; no dog needs a synthesizer.

 

 

[Nathanael_I]

I own a live sound production company.  These are my small subs…. They will move clothes at 10’ and are flat to 28Hz…. Very very useful for synth bass…. 

 

I am very happy to not have vintage anything also. And while I love pipe organs, I’d much rather have one of the virtual ones and NOT run Hauptwerk, but a stack of synths instead. Your point about portability remains true. But doesn’t stop my inner nerd from wanting to do it. It’s not a unique idea. Not even sure it’s a popular one, but somehow this thread kicked it off again in my mind. And now, having learned about the GX-1 through this thread, it seems only right to contemplate the GX-80 with the pedalboard!  (I so don’t have room in the studio for it right now).