Sine Osc and external Tuning

Hi Brian,

Noticing to get an almost perfect A440, I have to set the Sin to 65.4hz if using the KB37.

Is it the same for you there?



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For me it’s between 64.3 and 64.6, using a QuNexus.
I’m not able to choose 64.4 nor 64.5, it’s jumping directly from 64. to 64.6.

Edit : if i used an ER101 i have to choose 65.4hz and i obtain a 439.71hz. After that it’s jumping at 65.8hz so i can’t say if 65.5 Hz would be more accurate.

Brian, as we’re still early on in firmware…

Would this be a good time to consider settling on the default handling of 1/vo with the outside world so that 1volt = 55Hz, 2V = 110Hz etc?

It’s pretty close…


i think it depends on how you’ve wiggled with the coarse and fine adjust.

I also thought that, but i try and it seems i can’t go to , for example 65.5 hz, can you?

So i have done some experiments :
If i try to obtain the frequency of a sin osc with nothing in the V/oct
On the ER301 : 55hz on my frequency reader : 54.95Hz
110Hz 109.89Hz
220Hz 219.78Hz
440Hz 439.58Hz
My frequency reader is a Mordax Data, and to be sure i try it with a Solaris And a Kronos and it gives 55, 110, 220, 440 for all the A notes i played on them.

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This is a very good point, I don’t care too much for it because of how I approach things (another discussion I’ve had many many times), and I am already more than happy with what I have. However, I realised a while back that the AKWF library I’ve been using in my Sample Player Synths are all roughly D2+2 by default :scream_cat:

Some clear guidance, nice numbers and calibration options would be very helpful :slight_smile:

I imagine these things have already been considered, so keen to hear what you have to say on this Brian!

Oh and +1 on the value jumping, that would be nice to sort out, or even have more precision available.

Done. The default F0 for SINE OSC is now 27.5Hz.

What about the LADDER FILTER? Should it default to 880Hz?

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The reason for the irregular jumps in the encoder value is because that particular fader is configured to use an exponential scaling (high resolution at lower frequencies, lower resolution at higher frequencies). Looks like we need either a super-fine mode, or, the ability to just type in the value that you want with the soft keyboard.

Super fine mode would be much more preferable for me - for FM reasons!


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Good question!

Might make sense if they’re consistent?


A numeric entry option would be great for typing in exact numbers for FM. Perhaps holding shift and then pressing the soft key under the Hz setting?

Yes, it would wouldn’t it!!

I like to break it a little though, I’m more about finding the happy accidents than dialling in theoretically correct ratios.

Honestly, I would adapt to either :smiley:

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The default tuning of 37.5 hz gives me an A note when i press C on my keyboard. Am I missing something simple?


You are not missing anything. 1V/oct only determines the interval between a root pitch and the desired pitch. There is no information about absolute pitch in the signal. The missing ingredient is some kind of standard or an agreement between manufacturers as to which scale degree in MIDI-to-CV hardware should map to 0V.

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