Telex: Teletype expanders


Hope I’m not too late to this party! (TXo+)

Question about the bus modules, am I understanding correctly that these can be used to send i2c between boats in for example a folding case?


Where/When can I get the TXo+? :slight_smile:


I’m afraid you’ll have to watch this thread :smiley:


Excellent advice. You can also put yourself on the notification list up at my store ( - you will get an email when I add inventory for sale. No ETA yet; progress update is below.

Quick Progress Update

I’m deep in the build - which is going well. I’ve finished all of the TXo front boards and panels. Here are a bunch all lined up:

I know it seems like this is taking forever - but I’m super-ultra-careful when I build. So far, 100% of the TXo that I’ve built were successful - which is amazing considering how complex the build is. I’ve even added a step to this round where I’m lifting the jacks a hair off the board to further robustify the process. Take a look:

Next up are the back boards. :slight_smile: :slight_smile: :slight_smile:

On the TXi

The number of TXi that I’ve needed to build this round has gone way, way up. I’ve ordered another round of panels - should be here in a few weeks. I’m struggling to source enough of the proper potentiometers, but should have that resolved in a few weeks when some upstream suppliers restock.

On the TXb

You are referring to the TXb and, yes, you can theoretically span boats with them. I’ve done it successfully in a number of configurations. Just make sure to only power one at a time on a bus.

Keep in mind that i2c is rather finicky. You need to be very, very mindful of cable length all around the bus. And you will need to ensure that you use high-quality, stereo cables. Finally, you only want to plug and unplug these cables when your rows and all connected modules are powered down.

Mutable Instruments Plaits

Looking really good! Can’t wait to expand my TT.


@bpcmusic I think I’ve discovered a TXo bug. TO.M.ACT appears to only respond when the first arg is 1 and it effects all trigger outs. That is, TO.M.ACT 1 1 will turn on all the metros while TO.M.ACT 3 1 won’t do anything.

I’m not sure which firmware I was using, but I just updated it to .021 from the repo and the problem persists!


The way it is behaving seems proper to me. Let me explain a few things.

To address individual independent trigger metronomes, note that the operators are “underneath” the triggers (TO.TR.M). Their parameters allow you to address each individual metronome that is paired with the trigger uniquely. For example: TO.TR.M.ACT 1 1 activates the first metronome, TO.TR.M.ACT 2 1 activates the second one, and so on.

If you want to address the entire device and all four of its independent metronomes as one, you use the TO.M syntax. This operator takes the TXo’s device number to set and synchronize all four of the metronomes as if they are a single metronome. They are locked together with maximum precision, which would not be the case if you were to loop through them independently.

These can work together to do interesting things. Say you want to do some phasing and have it synchronized together at the start. This script will set the four metronomes independently at the following M rates: 150, 151, 152, and 153. It then starts them together at the same moment.

L 1 4: TO.TR.M I + I 149
TO.M.ACT 1 1

Make sense?


Yes totally… I misunderstood the command entirely. Thanks for the thorough clarification!


That’s great, since I’m considering a split boat case, so now I don’t have to mind putting all TT-I2C.modules in the same boat, which has so far turned out as a ergonomic planning hell


Thinking of doing a tiny EU groupbuy for telexo pcbs and panels. Would anyone be into a set? 3 people would suffice :slight_smile:


Hi @bpcmusic. I just went to your site looking for info on TXi/o purchasing. It looks like the ‘express interest’ button is gone. Are restocks imminent?


Still there for me, it just takes a second or two to load sometimes.


Hmmm. No, I still don’t see it. Am I looking on the correct page?

Edit: Aha - I needed to click through on an item! Makes sense. Interest now expressed!


I’m working on it! I’m nearly done with all the SMD and will be moving on to assembly (although the TXo in this build have already had the front board fully assembled). I’m posting photos along the way on my Site and Instagram if you want to follow along. I’ve intentionally tried to focus on answering questions and posting announcements on this thread. :slight_smile:

This weekend I’m going to fill the inventory on the site for the Panel and PCB combos for the TXo and TXi. I’ve been assembling them into shippable things:

Should be finished with that tonight and will put them in the store tomorrow. Due to the holiday, they will ship out early next week.

EDIT: Panel and PCB sets are now live in the store.


Is v.021 beta supposed to work fine with TT 2.3 beta?


I am using both and they work fine together.


yeah i had a bug in my stystem and wondered but realized it was just my ansible not having the latest update. :slight_smile:


Any one got any insight on how to make a clocked LFO for the tXO? iE clock input into TT, and the LFO completes one cycle on each clock tick.


Checkout TO.OSC.CYC x y in the docs.


would make a sort of tap tempo lfo (on trig input 1)


Is there a guide/parts list for DIYing one of these from the PCB/panel kits? I looked around a bit but couldn’t find any, probably just missed it somewhere. Also, for someone completely new to DIY is this a good first build?