Module Tester clock signal issues

#1

So I finally got my Module Tester build up and running and all looked ok as the menu, buttons, encoder etc. were working as expected, but once I started using the in/outs of the module I noticed the signals were pretty wonky. I was first testing with a multi-meter and noticing the clock output was giving me some kind of triangle ramp between 0-5V so I then hooked it up to a oscilloscope and this is what it read.

27%20AM
27%20AM905Ă—508 21 KB

I then tested all the other channels (gate out, cv out) and they all showed similar readings.

Could this be a power supply issue? I am always super confused with the difference between AC/DC power. I was using an AC adapter (at least I think I was) but it stopped working after about 10 minutes (no clue why) so I switched to one with an input: 100-240V and output: 12V -...

#2

What I see here is a perfectly fine square wave going through an AC-coupling (DC-removal) filter. Not sure what scope or probes you’re using, but there’s an AC-coupling setting or switch wrongly selected somewhere.

1 Like
#3

Is the output DC or AC? maybe you could post a photo.

Also, it would help to know which version of the board you’re building!

#4

I am working with v2. Here is the power supply.

IMG_0988
IMG_09883024Ă—4032 2.05 MB

I am using my MOTU828 as an oscilloscope so theres a chance it doesn’t work quite like a “real” oscilloscope, but I am unfamiliar with the tool. I’m going to test it out a bit more.

#5

Audio interfaces are mostly AC-coupled. You cannot use them as oscilloscopes for signals with frequencies outside of the audio range (including DC).

Your PSU is fine.

#6

Some versions of the MOTU 828 do have DC-coupled I/O, I think, as they can be used for CV input and output with Silent Way software.

https://www.expert-sleepers.co.uk/siwacompatibility.html