Telex: Teletype expanders

Yeah, mine switched status sometime yesterday evening. All good, thanks for checking :slight_smile:

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Yesterday I came across something that could be a bug:


This gives me the expected behavior of producing a subtle LFO.

Now if I do TO.CV.OFF 1 V 2, I expect to get the same subtle LFO shifted up two volts. But instead, it is the range of the LFO that changes to V 2, as if I had entered TO.CV 1 V 2. Is this normal behavior?

I am on v.018 and the behavior is reproducible.

Received my TXi/TXo bundle on Thursday and had a blast last night writing scripts for them. Thanks @bpcmusic! I ran into one issue though which I’m sure is user error. I had setup an envelope on TXo output 2 that would not trigger. The same script was outputting CV on TXo 1 so I know the script was firing. I eventually gave up and saved the scene. This morning when I loaded it up, the envelope triggered as expected. I know there are keyboard shortcuts to mute scripts. Is there also one to mute outputs that maybe I had accidentally hit? Thanks!

Hey @bpcmusic i just received my secon TXi and read the “TINY HINT” note. I got to say that i am a bit worried each time i take the modular out because of the boards connection so i am really considering what is written in the LUDICROUSLY SMALL HINT part :upside_down_face: I already DIYed some modules so from what i saw it should be ok but i would be really reassured if anyone could post a picture or two of successful boards soldering… I don’t what to fry my babies…

Apologies for being a little out of touch these last few days. I’m literally on the other side of the world from my home through the end of the week. Still trying to figure out what end is up!

Yeah - I discovered something similar when I was playing around with it before I left on my trip. I found that the sequence was important. For example, this worked:

TO.CV 1 V -5

But, if I put the offset AFTER the CV setting - it didn’t. Try setting a CV value after the offset for now. I’ll look into the fix when I’m back in the states this weekend / next week.

Sorry. That used to work solidly. Somehow I let a regression slip in back in July. :frowning:

I haven’t seen anyone who has done it yet. I keep mine separate for QC purposes. Anyone solder their boards together?

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So, what are those tiny and ludicrous hints? Sounds mysterious…

:grin: It is just a piece of paper that you find in the modules box describing how to take care of the expenders by checking that the 2 boards don’t unplug when you move you case.

Managed to snatch one telexi, really hoping to at some point get another one along with 2 telexo!


No special keyboard shortcuts for the expanders. Just operators.

Can the outputs of TXo be mixed passively with a multiple like they can with the Mannequins modules?

Suggestion for future firmware: calibration (or at least a zero nulling procedure) for the TXo’s CV outputs. I’m seeing around -19mV of offset at CV 0, which is enough to be audible when e.g. switching the CV in and out of an oscillator’s pitch control. I can of course offset by around +30, but calibration would be super nice too. :slight_smile:

Seconded. Some of the CV outs have a noticeable offset at zero.

Good question; don’t know why they wouldn’t be able to be. To be honest, I’ve never tried it. Anyone?

Got it. Expect a new release in the next week or so. :slight_smile:


I couldn’t find docs for using teensy_loader_cli, so dropping what I did here in case it helps anyone.

On arch I installed teensy-loader-cli-git from the user repo.

Docs on git said the teensy version was 3.2, which yields the following command to update: teensy_loader_cli -mmcu=mk20dx256 -w -v ./TELEXi.hex.

Not sure about the normal process, but I think the -w flag requires you to push the small button on the back of the teensy.

Everything updated easily after that.

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That is super-helpful; do you mind if I put your instructions up on the TELEX Github site?

Thanks so much for sharing!

Of course not! The docs were pretty complete:

Arch handles resolution for the libusb dep, but that might be the only other gotcha for other distros or compiling from sourc.

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I soldered together my Telex boards yesterday while I had the modular apart during a power supply transplant.

There are (2) two pin pairs near the top and bottom, just carefully cut away the plastic around the pins (I only broke one pin on five Telexes, but I have a vacuum desoldering station …), clamp or rubber band the module together to seat everything, then solder a total of four pins per module. The modules are rock solid after that!

Oh, and WEAR EYE PROTECTION when cutting the plastic! I had a piece hit me in the nose nearly hard enough to draw blood, it hurt!


Ok so 4 would be enough… I was about to desolder every female plastic parts (but then the module would have been slimmer).



Pics or it didn’t happen (the mod - not the injury). Glad it went well!!

Offset Behavior

I’ve identified and fixed the bug with the offset behavior. New firmware will come later this week after some more testing as it won’t be the only thing in the release.

If you want to get around it for now - the key is to have the SLEW for the CV output set to a non-zero value. It defaults to 1ms at turn on and, with that value, the logic error doesn’t exhibit itself. Unfortunately, if you set the SLEW To zero or use INIT (which also sets it to zero), offsets then don’t get applied until a subsequent CV voltage set command.

In short, the workaround is to keep your SLEW for the CV at 1ms. When it is set there, the offsets apply immediately.

New build should be ready before the end of the week. :slight_smile:


Wanted to share an early peek into a study that I’m putting together for the TELEX. It uses @scanner_darkly’s grid ops to turn a TXi and TXo into a little polysynth. I still have some polishing to do on the patch, but here is a quick preview:

There are only four modules involved in the patch with only one sound generator - the TXo:

  • Teletype with Grid
  • TXi for controls (attack, decay, waveform, portamento)
  • TXo for audio output (4 oscillator + envelope combinations)
  • 2hp Mixer to mix the voices down

(The O’Tool visualizer doesn’t count - just wanted to make the video a little more interesting.)

If you look closely at the pattern view, you can see the crudely scripted voice allocator at work. It “stores” the active voices in one of the first four positions in pattern 0. The script has one variable parameter that allows you to open it up for more voices if you have multiple TXo.

It’s a potent combo. What is amazing is how little grid-specific scripting that I had to do. @scanner_darkly has done a wonderful job making the grid a super-useful input device in the smallest number of lines of code. It is super-powerful!!!