Telex: Teletype expanders

Although I’ve already pm’d @bpcmusic about my interest I thought I’d add my name to the public list as someone who will order 2 TXo’s and 1 TXi - possibly 4 TXo’s and 2 TXi’s after I get feedback from @emenel and @scanner_darkly.

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Same here! I’ll go for one of each Telex if the second run ends up happening!

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I am not either of the people you mentioned, but I have often thought about another TXi. just having the extra Param and Ins to poll for values is incredibly useful. Also, more knobs mean more immediate control over the various envelopes, LFO’s, offsets, oscillators… etc that you may be running on your Teletype/TXo’s!


I use the envelopes and cv outputs on the TXo a lot, so I could see a second one being really handy. Same with the additional inputs and knobs. I also have been exploring using it as a quantizer, so having more ins and outs will mean I can keep using other functions at the same time.


So it’s looking like I’d be making a safe bet if I opted for 2 TXo’s and 2 TXi’s…now the question for myself becomes how intrigued am I by setting up with 4 TXo’s like I saw with @scanner_darkly for driving everything on a 4MS VCAM or setting up a wicked patch on the Synthtech E370 I’ll be receiving in the next couple of months?

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I’d recommend starting small. Do you have a Teletype yet? It would be good try it out and see if you like it and it works for your workflow before investing in the whole ecosystem. That and the Telex expanders are not currently available other than the used market, since they were a very small hand made product.


Once the next batch of Teletype are available I’ll be purchasing it. Regarding the Telex units, considering the rarity of them and limited run I think it would be in my best interest to get them once they come up again. Seems I could easily sell a unit or two should I decide on that path at a later date. I’ve been considering this move towards Monome for some time now, not years but relatively patiently studying what is what before taking the purchase step seriously.

Regarding my workflow…this is not an endeavor to make a thing as much as a road of discovery, a way of exploring digital nature while I’m at home. I stopped watching TV in 1985 and pretty much stopped going to the movies about 15 years ago. In the early days of Techno in Germany I taught myself 3D graphic design and made record covers. Moved back to the states to participate in the Internet economy, wrote a book along the way and I’m now using Eurorack as my primary tool of entertainment. So on a day-to-day basis I wander into the electronic woods and up the bit-driven trail to find surprise at what is across the voltage. This stuff is hard, brutal sometimes but it’s better than growing old and passive relegated to reruns out of the 70’s or playing 32 years of Mario Bros. Probably TMI but I love this human activity of communication :slight_smile:


@unity2k have you ever tried soldering? You might enjoy it, and it’s currently the fastest way to get a TXo or TXi. A few folks around here have successfully built them, and you might be able to do so as well.

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I’ve not soldered before and I read @bpcmusic’s narrative about needing to be familiar with SMD soldering which from other DIY kits seems to always be the weeding out factor. I’ve used Raph from Michigan Synth Works and was looking to him for a Turing Machine and there’s Kel over on the Orthogonal Devices forum that seems to be building a few things for people.

I’m definitely not in a hurry as first I need a Teletype, I just want to make sure that if Brendon does decide to build more Telex units that I’m not late to the party.


I’ve built two TXis and two TXos. It’s not an easy first project due to the part sizes, but it’s definitely not an insurmountable build. @bpcmusic’s documentation is the best I’ve seen for a DIY project, especially with the part maps.

If you want to learn soldering for the sake of Eurorack DIY, I would build these three @TomWhitwell projects in this order:

  1. Mikrophonie. Very small part count. Costs next to nothing to build if you order the parts yourself.
  2. Radio Music/Chord Organ. Extremely similar build to the TX modules (4HP, Teensy, stacked PCB).
  3. Simple EQ. 4HP SMD build with easy-to-source parts.

Turing Machine mk1 was my first build. I haven’t built the mk2, but I imagine it’s quite easy. If you want another training build, I’d do the TM before the RM.

This is a great thread to read through:


The TXo and TXi were my second and third SMD projects. With a bit of help and support I finished both and am very happy that I took the plunge! Just used a standard iron, SMD tweezers and a good magnifying glass.

I already had a bit of soldering experience with the much bigger 5U modules I built over the last 2 years and started with the Simple EQ as a first step to practise SMD. A great module to patch in feedback paths by the way!

In hindsight I cannot recommend enough to start DIY as early as possible - there are so many great things to build out there and the more of your system is actually self built the more you feel connected to it. Plus there is a lot to learn about what is actually going on there. It might safe you a lot of unnecessary expenses too and it does not feed the wide spread modular consumerism that much.

What helped me a lot was this video, which is as much fun as encouraging - I learned through hole soldering with parts 1 & 2 btw:


Quick Update for Those Interested in Obtaining a Pre-Built TELEX

I’m mid-way through a small build of my remaining PCBs and panels. No ETA as of yet, but I’m aggressively moving forward to wrap it up soon.

There will be no pre-orders or reservations this time. I’ll be opening up a little Shopify store with the units are ready (store is already built). As they are technically a part of the previous run, pricing will be the same as before. I’ll post to the this thread when the store is launched.

I’ll also skip the step-by-step forum updates this time. I will post photos from time to time on my Instagram account (

If you are curious, I’ve finished all of the SMD work and am on to module assembly. I’ll then be testing, packaging, and building out some of the accessories. Since the quantities are substantially smaller than the last run, this all should go fairly quickly.

Some TXi awaiting soldering:

TXi front PCB in the custom 3D printed assembly frame (OpenSCAD and STL files are in the TELEX repo):

Precision headers snipped and ready for use:


Awesome! that’s great :slight_smile:

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Much excite! 20 characters!

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just what I’ve been waiting for. Awesome news!

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Damn it unity2k … I saw the thread bumped and thought that I had missed out again :slight_smile:
… back to refreshing Instagram.


I’m still deep in the build. Don’t worry about missing the store opening - I’ll give plenty of advance notice and supply an exact time.

Mid-way through the process (3/4 through the build) - though I’ve had to order some additional parts and accessories for completion. Finished the TXo and am onto the TXi back-sides next:



What will be the price for these btw ?

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Well, I just bought a Teletype, so now I guess I definitely need these too, based on how all of you are acting. #extracompetition


Are there any PCBs and panels available right now? Or should some of us who want those get together and do a run of our own?