The Official Sequential/Oberheim Forum

SEQUENTIAL/DSI => Mopho/Tetra => Tetra => Topic started by: moogmusic on April 11, 2022, 02:47:31 PM

Title: Osc Freq Setting
Post by: moogmusic on April 11, 2022, 02:47:31 PM
Hi, I'm a bit confused trying to program my Tetra - when I set the Osc Freq parameter, how does this relate to the MIDI note? If want the oscillator to play at the frequency of the MIDI note I'm sending, do I set it to C0 (the lowest) or C3 (middle C)? Or something else? It's not really clear from the manual. Thanks
Title: Re: Osc Freq Setting
Post by: sixcontrabass on August 08, 2022, 09:07:42 AM
If want the oscillator to play at the frequency of the MIDI note I'm sending, do I set it to C0 (the lowest) or C3 (middle C)? Or something else? It's not really clear from the manual. Thanks

Hello there. 

Your question made me think actually given the information at the end of this reply. 

Checked with a single oscillator set to Triangle, C3 with no modulation etc etc and played middle C, (Midi Note 60).  The analyser in Logic X channel EQ reports back that the fundamental is in the 261Hz region, (C below Mid A 440Hz). 

So C3 on the Osc Freq would mean the pitch delivered corresponds to the note played on your midi keyboard.

Note that Dave Smith Instruments and others defined mid C as C3 at that time, (Midi note 60). 
I believe Sequential still do, as well as many others.

Classical/Piano music suggest that C4 is mid C, 261.626Hz, which makes sense when using 188 key piano's.

For Mid C, Midi Note 60, apparently could be C3, C4 or even defined as C5!  I believe the Yamaha DX7
defined mid C as C4 but I can't remember seeing a device that defined it as C5. 
Anyway for this enquiry lets
just go with the definition as per the DSI device.  :-)