Sin Osc not tracking 1V/Oct?


I’ve read all the posts I can find about the Sin Osc and pitch, and I believe I have a good understanding of how it is meant to function. I just spent the afternoon testing the pitch tracking of all my systems oscillators; two Dixie II+, a Mangrove, Rings and Elements and of course the Sin Osc on the ER-301. I was using a quantized CV output on a Varigate 8+ as my CV source connected to the V/Oct input of each sound source. All tested perfectly except for the Sin Osc on the ER-301 on which I noticed two problems.

The first issue I noticed is that my Sin Osc seems to be a bit sharp from what f0 says should be the baseline when 0V is applied to the V/Oct input. For example, with f0 set to the default 27.5 Hz (which is an A) my O’Tool + reads the output as a 27.993 Hz, so off by over 400 cents.

The second, and more concerning to me, is that the Sin Osc did not track 1V/Oct for me. For example, with f0 set to 32.7 Hz at 0V input, then at 1V input which should be one octave up, I was seeing 89.872 Hz (on the cusp of F/F#) instead of the expected 65.4 Hz ©.

I feel like I have a good handle on this (I’m an electrical engineer) but maybe I’m doing something wrong.

Anyone else seeing the Sin Osc not tracking 1V/Oct?


Probably the small offset from the cable. I would turn on the readout for actual value (new in a recent firmware) and tune the oscillator after inserting the cable and assigning.

Also make sure you don’t use the 4 audio inputs, but the abcd inputs.

What inputs are you using on the ER-301?

Edit: ahh @jonny just answered…my reason for asking the same as his suggestion.

Regardless of whether this turns out to be the issue or not, I think I’ve just realised why this ‘in’ vs ‘abcd’ input question keeps coming up, it’s the physical proximity of the ‘gate’ ins to the ‘in’ ins - a convention used extensively elsewhere.

But did you read the wiki? :stuck_out_tongue_winking_eye:

I’m glad you posted though before getting too frustrated.

Now waiting on the answer to the big question. Which input did he use?

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Lol. I may be guilty of not reading it all…

I used “In” on channel one. Did I miss that those are not to be used for V/Oct inputs?

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That is correct. INx are not calibrated for V/oct.

Thank you everyone. I’m sure if I switch to using ABCD I’ll be fine. I’ll reply here after I test tonight but sounds like I made a newb mistake!

And… pitch tracks PERFECTLY 1V/Oct now that I’m using A1 as the input for the pitch CV. Doh!

So happy to have that figured out! :smiley: