Hermod CV Out Issues

I sent this over through the Squarp site already, but thinking maybe the community can help?

I’ve been using my Hermod for a while without any trouble but a few weeks back it started having an issue sending CV out. Whether I play notes on a midi keyboard (Keystep) or try to program them in through the Hermod interface, the output CV does not change as expected.

For most midi values, the output is the same note over and over, and it is very very low. I do get some CV variation as I move up the keys, but it actually seems to work in reverse–as I move up the keyboard, the notes descend slightly. This happens across all channels.

Here’s a video of the issue: https://www.dropbox.com/s/b2gjucw7zrlb0d1/VID_20200311_122437.mp4?dl=0

I’ve updated the Firmware to the latest version and also downgraded (per recommendations from Squarp) but neither resolved the issue. I can use other CV sources with the sound modules so I’m sure everything else is working as expected.

Thanks for any help you can provide!

  • does led colour changing as each step puts out a new note? (I assume it does, but cant see on the video)
  • are you getting the same behaviour if you output a modulation track (e.g. an LFO)

assuming its not a hardware issue,
id wonder if the calibration data has been screwed up. have you tried re-calibrating?
details are in the manual…

note: there is no ‘reset to factory’ option, so ideally you need an accurate voltmeter or similar… that said, you don’t seem to have much to lose, if the hermod is not sending out voltages anyway…

if you don’t have a voltmeter, you can just tell hermod it is sending out the correct voltages… it might not track perfectly, but at least you should see its back to changing voltages correctly

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Thanks for the response!

LEDs do not change color from note to note, just the expected blinking for the gates. Other than that it is a solid green light.

Yes, seeing the same behavior for a mod track, which in fact has led to a new discovery… it seems like the CV in is having trouble as well. I haven’t used the mod feature a lot yet (only had this module for a few weeks when it started acting up) but I’m pretty sure I set this up correctly. Made a new video of this problem. In it, I’m showing how I routed the Mod Input A to affect the channel I’m on, recording that channel, then just messing with an output from Maths to send some voltage for it to track. Hermod isn’t picking up any of it. Video here: LINK (Note: sound not recorded on this one. It was just a constant tone coming through the headphones)

Also, I tried the recalibration you’ve recommended but that didn’t seem to change anything. I don’t have a voltmeter, so not totally sure if anything is changing at all, but I’m not hearing any differences from octave to octave as I work through those calibration steps.

that seems odd in itself… for a note track the colour/intensity of the LED reflects the cv note output.

if you create a MOD track, and put and LFO on it (default make sync = OFF, amount=200%) , do you see the LED pulsing - as this indicates the voltage output.

I couldn’t really see what was going on in your video… so hard to tell if that’s working or not.
but if you’ve had this working before, and now its not… then doesn’t sound good…

have you talked to Squarp about it? it is sound like a hardware issue.
(though… I guess they will be in lockdown, so might not be much that can be done for a while)

I had the same kind of issue: no pitch change from CV outs. However, the following things solved it in my case:

  1. Checking if the module has sufficient power (mine didn’t, which resulted in buttons not always responding, and no pitch or modulation CV change on the outputs).
  2. In Effects, on the first (obligatory) MIDI effect set the Effects to Gate Retrig > On, and Root Note 0V > 12.
    The module is brand new, and it was the first time I used it. Everything works great now. Hope this might help you.


Did the LFO test you outlined, no pulsing in the LED, and no change when I plug the output into something. Just that same low voltage. Yes, sorry about the bad video - mainly trying to show that I’m not getting any feedback from the LEDs, and no expected voltage changes (either note or mod) from the outputs. I think you might be right about the hardware issue, unfortunately. I have been in touch with Squarp about it, but with everything going on right now they’ve (understandably) been slow to respond. Of course I’m glad they are prioritizing health and safety, I’ve got plenty of other stuff to mess with for the time being.

Thanks for the suggestions. I should have plenty of power for the module. I’ve got an intellijel 7u which should give 3000mA at +/-12 V, and 1500mA at +5. Modular Grid shows me currently using 1153 +12V, 388 -12V, and 0 5V. Furthermore, the three power lights in the 7U case all light up, so I’m thinking power is sufficient.

As for the midi updates, I’m not sure the Gate Retrig would have a big effect but I double checked it anyway, no luck there. Same for the Root Note. Tried voltages 0, 10, 20, etc. up to 120 and no change.

Thank you both for your suggestions. Keep them coming if you have any other thoughts!


As you suspect a hardware issue, what I’d try is unplugging every other modules except Hermod and another to test with. That way you could discount power issues.

Hey - Just got my Hermod today, and I’m having this exact issue. Is it a hardware issue then? Did you end up hearing anything back?

Maybe I should send this unit back to Perfect Circuit.

Thanks for the bump! I did get this fixed recently. After letting the module sit in its box for about a month I decided to give it one last go before starting the return process. I pulled the SD card, cleared it, and reformatted the whole thing. Then put a fresh version of the software file on the card and went through the startup process. No idea why this time was different but it has been working fine ever since!

The only think I can think is maybe the reformatting helped, or there was something that got corrupted in the file between updates? Anyway, should have tried it sooner but the full wipe/reformat/clean install worked for me. Good luck!

I think I figured it out. Hermod’s default is “0” root note in the midi settings. When I initially try to fix that, I’d already been recording a bunch of notes. Anyway, I tried again and set the root to “20” prior to playing any midi input, and everything was a-ok! I think this root-note setting is new as of the latest firmware, but seems like a default of something other than 0 might make more sense so folks can get up and running quickly.

which version of HermodOS are you on?
as root note changed slightly - i thought current release it was 60 by default, beta is different… as that’s now expressed as an offset.

anyway, regardless of release - the idea is that root note allow you to alter where 0v is in relation to midi note. by default it midi note 60 (c3) = 0v.
most keyboards/controllers base there 0 octave at C3.

what midi note number is your controller sending in?
how have you tuned your oscillator? what voltage range does it accept?

my ‘guess’ is you’re sending in midi below 60, and your oscillator is tuned such that the negative voltage is below its range?
(someone reported something similar before - something particular about the oscillator/sampler they were using?!)

I have 1.42. Root note is configurable between 0 and 32. But I did see that in True Cuckoo’s tutorial it was set to 60 by default - but that was an old video, likely pre-1.42…?

I’m getting a bigger case arriving Monday and can then hook up my zeroscope which should allow me to take a deeper look. I’m using Keystep as the midi controller btw.

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yeah… I believe 1.42 went to the new approach… and so the manual is a little out of date.
(but I was a bit unsure, as it didn’t mentioned this in the release notes)

yes, the older approach was to use the midi note number - but that led to some confusions, hence the change.

cool, that’ll make it more obvious.
also use a midi monitor… so you know what midi note number your keystep is putting out, and that should complete the picture for you.

back to your original point… +24 (Im surprised you say +20, that should be off by 4 semis) would not be a good ‘default’ for other setups, e.g. that would throw my setup out by 2/octaves… but thats the setting exists so it can be adjusted depending on setups, and the oscillators (etc) you are using.