Recently, I’ve been thinking a lot about better ways to use Dexed in a DAW. Specifically, I’m interested in layering the same sound upon itself to “thicken up” the 6-op FM sounds that Dexed already makes. Beyond that, though, I’m interested in synthesizing new sounds by layering *different* FM sounds upon each other. In hardware, this was generally possible on the Yamaha DX family in the Yamaha TX816 – a monster FM synth that had the equivalent of 8 DX7s in a rack-mount unit. In this post, we’re going to recreate a TX816 using Dexed in Logic Pro.
What is the TX816?
Yamaha released the TX816 in 1984. It was a follow-on to the DX7, made up of a 4U rack-mount chassis and slots for 8 synthesis modules called TF1s. The TF1 was essentially the synthesis engine of the DX7 with a very limited user interface. The TF1, primarily designed for use in a studio environment, is also reported to be quieter than a DX7. Since having a fully loaded TX816 was equivalent to having 8 DX7s, you had access to 128 voices of polyphony.
Naturally, editing was a challenge without a computer editor, and in 1984, even those were scarce. The user could, however, send DX7 System Exclusive voice data to each TF1 module – so at least one had access to a programming interface via the DX7.
These days, TX816s are available on the used market for around $3,000 USD. We, however, can recreate much of the TX816 vibe with modern DAWs, Dexed, and GUIs. Let’s grab our overalls, prop the hood open, and get started.
What makes a great TX816 sound?
The key to the great sounds created for the TX816, at its core, was a single DX7 sound across all eight modules, with slight detuning and slight delays between the voices. This is a common way to fatten up sounds, and is largely what many VST synths do in their “unison” mode, where the programmer can select the number of simultaneous voices and the amount of detune between them.
Searching for the Yamaha, you will find videos on YouTube of the TX816 series like this one here: https://shorturl.at/CgrSB – that’s essentially what is happening. Dexed doesn’t give those tools to us natively, which I’ve highlighted in the past in this post. Let’s start by attempting to create an 8 x Dexed stack with some slight delays and detuning, in Logic Pro.
Steps in Logic Pro
Logic Pro gives us the tools we need to build a single track with 8 instances of Dexed, with programmable delays; the detuning involves a little more. The primary method for doing this is to create a Summing Stack. This combines the audio signals from multiple tracks, each with Dexed, into a single aux mix channel. With this aux mix channel, you’re then able to apply effects, automation, and volume control to the entire stack.
Let’s start by creating a new Project in Logic called “TX816.” Next, create 8 Software Instrument tracks, all selecting Dexed as the AU synthesizer plugin. Now, for each of the instances of Dexed, let’s assign the same sound – I’ve chosen Chroma 5Y from the default Dexed bank, because with it’s sharp attack and longer release, it will show off the effects of stacking really well. To copy this track, select in a type Command D (⌘ D) seven more times to create all 8 tracks.
Next, Shift-Select all 8 tracks and Right-Click, selecting Create Track Stack…, then choose Summing Stack from the two choices. We’ve now created a Summing Stack called Sum 1, which we’ll rename now that we have a chance to “TX816.” Now we can note that as we play notes on our controller, we see all 8 instances of Dexed playing Chroma 5Y – an 8-voice stack of FM goodness. Next we want to figure out the delays and the detunes, so let’s take a look at that.
One broad-brushstroke way to simulate the chorused effect of 8 detuned DX7s is to use a Chorus or Ensemble effect on the TX816 Summing Bus we created. That sounds great, but it doesn’t sound like a TX816. What we sadly must do in this case is slightly modify the Tune parameter in the lower-left corner of the Dexed UI for all but one of the Dexed instances on a track. Sounds like a pain, but it seriously took about a minute. Let’s leave the instance on Tracks 2 and 9 as is, then slightly tune “up” Tracks 3, 4, and 5, then slightly tune down Tracks 6, 7, and 8.
When you select the TX816 Summing Stack, you’ll now hear a very fat version of Chroma 5 Y, hearing 8 voices per MIDI note you play. Later, as you experiment with this further, you’ll learn how far you can detune to achieve maximum thickness. To my ears, too far beyond +/- 10 cents starts to sound wonky. For this post, small detunes are all we need. This gives us a layered stack of 8 Dexed instances, and it sounds thick and fat. But I think we can take it a step further.
How can I make this easier? with a Script!
I’ve created a Scripter preset to use to get you started. It has a programmable Delay amount per voice and, once you program the target to be the Dexed Master Tune value, the ability to detune each component within the Dexed Track Stack that we created. Let’s walk through how it works.
First, download the Scripter preset here. You’ll want to place this preset in the appropriate Scripter plug-in presets folder. On most systems, that is located here:
[your name]/Music/Audio Music Apps/Plug-In Settings/Scripter
We can save a bit of time setting this up if you add the Scripter MIDI FX to a track within the Track Stack first, program the target to be the Dexed Master Tune parameter, then use Cmd-D (⌘ D) to duplicate the track with Scripter already assigned in the MIDI FX section.
There are shortcomings (a nice word for bugs) in this script. First, keep in mind that if you adjust the detune parameter, then turn off / bypass the Scripter plug-in, the instantiation of Dexed will remain out of tune. This is exactly how it would work if you had a hardware controller manipulating the Detune parameter and then turned the controller off. Technically, not a bug, but it could be considered unexpected behavior, which I place in the “bug” bucket. Just turn the Script back on and adjust the tuning as needed.
The second bug is also related to Detune – if you change the target parameter to something other than the Dexed Master Tune after you have detuned the instance of Dexed, it also will remain out of tune. I think I can fix this one, and I’m still working on it. When I fix it, I’ll place an update notice at the top of this post. In the meantime, with both issues, please keep in mind that you could end up with a component out of tune on your Track Stack. Again, just re-assigning the target parameter to Dexed Master Tune and adjusting will fix it as a workaround.
A walkthrough of setting this up in Scripter
A video walkthrough of setting all of this up is here:
If you are more of a step-by-step learner with text, follow this procedure:
1. Open Logic, create a track with Dexed as the software instrument
2. In the MIDI FX section, add the Scripter Effect, and load the Dexed to TX816 preset.
3. Press Command-D (⌘ D) seven times, creating 8 total instances of Dexed
4. Select all 8 Tracks, Right-Click, select Create Track Stack…, then choose Summing Stack
5. Experiment with various presets, delays, and detuning values
There are lots of options here. The practical use of a TX816 in the studio wasn’t necessarily about stacking 8 instances of the same sound, although that was definitely done. Personally, I find the 4+ 4 approach the most effective – two distinct voices with four instances each, all slightly delayed and detuned. Massive FM sounds await if you try this.
We made Dexed bigger
So there it is, an approach to recreating a TX816 using Dexed and Logic Pro. I’m sure that any DAW can do something similar. In fact, it’s my plan to post something here to do the same in Bitwig. That said, I’m certain most major DAWs can create the equivalent of a track stack; I’m just not sure about the idea of a script-like creation of delay and detune sliders. I’ll post what I learn as I experiment with Bitwig.
In our Dexed Owner’s Manual, there’s a complete set of tutorials, from downloading and installing Dexed to advanced FM programming lessons, all located within. I’m going to continue building on this list of posts and have several more planned for the coming weeks.
DexedOwnersManual.com is full of ideas for maximizing your enjoyment of Dexed. I encourage you to join our mailing list – that will get you a discount coupon to use anywhere on SoundEngine.com, for Dexed sounds or not. We’ve got similar sets of tutorials for Nils’ K1v, a Kawai K1 emulation, as well as Logic’s Sampler VST and MIDI SysEx messaging and management. I hope you’ll join us.
In the meantime, thank you for reading this post on creating a TX816 in Dexed, and I hope it has given you some creative horsepower for your tunes.
Resources:
- SoundEngine’s Complete Dexed Owner’s Manual Series:
- Our custom programmed Crankshaft: Dexed bank:
- Our custom programmed Flywheel: Dexed bank:
- The Dexed plug-in:
- FM Synthesis:
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