DIY : tsnm (Touch Sensing Note Memory) by Doboz


I took the faceplate off to inspect it, but the pads are triggering the lights, but its stuck


I’d reflow R9-R13, looks like there’s possibility for a loose joint in there (use lots of flux)
It looks like the pad pointed to on IC5 is not soldered?
Looks like you’re missing R18 entirely


also check this.

I’d also verify that there are no bridges on your ICs using a loupe, especailly IC1 and IC2


I checked for bridges under a microscope earlier and there weren’t any. Is that not c10? on the BoM it says not to populate it


Oh yeah, it could be c10. I’m not looking at the build guide, just going by what I can see (I haven’t built one of these, but have done loads of surface mount soldering)

on another note, why did they use 0603 on this board, it’s unnecessarily small for such a huge PCB with so much space. They could have easily gone for 0805 or hell, even THT or 1206 with no problem. Given that it’s a kit only build It seems pretty strange to have gone with 0603.


Yeah, it is strange. It’s good practice though? The extra space does make it easier. :laughing:

@psychocroissant, are you sure IC1 and 2 are oriented correctly? I have no idea what the beaviour is if they’re placed backwards, but that’s a thing to consider at least.


I think they’re correct. The text is facing the encoder. I think it might be the teensy. Ive had it for around a year in a box in my closet. I just ordered another to test my hypothesis.


Seems like it’s working, thanks all the support! I haven’t had time test everything.

I test the calibration. I thought there was a problem at first but then realized all the keys were tuned to C :grimacing:


Calibration is definitely important! But it should mostly work right away if you use one of the sanctioned touch boards.

My least favorite thing about the unit is how quantizing works. Save a default preset that you like ASAP. :+1:


I’m testing mine out and I can’t get the pressure CV to do anything? Do you have to set this as a mode? I get pitch, trigger and gate CVs. I measured the output of the pressure CV and it shows -10v?

You you need to configure pressure from the menu?

I also seem to end up on a menu item that is “h!” which isn’t in the docs?


Just thinking out loud.

My pressure CV seems to always show -10v. Looking at the schematic this part of the circuit seems pretty straight forward. It’s a non inverting amplifier built with a single op-amp. Looks like the gain is 3.

The input comes from the Teensy. If the Teensy puts out 0v to 3.3-5v this generates a CV of 0v to 9.9-15v.

There can’t be a negative voltage from the Teensy. So to get a negative value at the output of the op-amp either the input is not right or the voltage at the inverting input is way off.

Or, and there is precedent for this, I miss measured the CV. If I mixed up the probes it might be +10v. This seems more possible. If this is the case it might be harder to debug since it could be at the Teensy.

I’ll have to take the board apart and measure the voltage at each pin of IC5.


h! is HOLD when in Arp mode. I believe you press the encoder to enter/exit that mode.


Voltages on IC5 are

  1. 0
  2. 0
  3. 0
  4. -11.86
  5. 0
  6. -3.46
  7. -10.42
  8. +11.79

Not sure what’s going on but there is something wrong with this. Pins 1-4 and 8 look good. But pin 6 and 7 seem off.


Okay, I got this working. Why did anyone tell me you need to solder that one pin on the end of the Teensy! It never occurred to me. I soldered the two rows. Didn’t even notice the pin A14.

Hard to see look closely to the lower left of the switch. There is one extra pin on the end.


Then of course there is a spot on the circuit board.



Playing around with the tsnm. This is a really cool input module, but I’m have a problem, maybe I’m missing something.

In Kb mode, I set the first pad to C, and tune my oscillator to C. Then I set the second pad to C# but the note is D, up a whole step from C#. The display shows C#.

Then, I set the third pad to D, the display shows D, but the note doesn’t change it’s same as the second pad that shows C#. If I tune the note pad to D#, this note is correct its D# and the display shows it.

I’m using Braids. Not sure if this would effect anything.

As I go up the scale the display shows the note but one times the not doesn’t change the pitch an other times it will. For example E and F have the same pitch, F.


Never mind, I’m an idiot, I had Braids in Quantize mode, oops!


@doboz great module super fun. I’m picking up the menu system fairly quick. There seems to be many useful options to explore. It’s well worth the HP it occupies. It’s great for live input, sequences and arpeggiation.


When set notes by holding a touch plate and turn the encoder when I get to B the LEDs show H! The notes continue with C in the next octave after. What’s going on here? Everything is working but why H?


It’s a different notation convention — a pretty rare, geographically specific one. And one with quite frivolous motivations, if we believe the Wikipedia page:

“However, in Germany, Central and Eastern Europe, and Scandinavia, the label B is used for what, above, is called B-flat, and the note a semitone below C is called H. This makes possible certain spellings which are otherwise impossible, such as the BACH motif.”


:man_facepalming: I’ve never heard this, thanks for the reply, you learn something new everyday!