Sub Oscillator Questions

Zoniq · Joined: Jun 21, 2018 Posts: 1 Location: Canada

Hello everyone, I've been searching for ideas on sub-oscillator. I don't have enough background to be able to understand the concepts tho' thus my questions.
Looking at the Sub-oscillator i.e Juno60(and others) which is basically your lowest freq f/8(16')/2 to obtain (f/16)32' added to the pre-filter mixer, whereas other sub-oscillator(modulars) seem to mix/add more frequencies together, is this like adding/mixing all the footages together?
My idea was to do a smooth sweepable footage from 2' to (sub) 32' (not step switched) but would this cause unwanted frequencies or harmonics?
or are these two basically the same idea ? any synths do this type of thing?

I'm sure I saw a schematic with some resistive network somewhere but can't seem to find it anywhere anymore.

thank you in advance

VA1 · Joined: Aug 20, 2018 Posts: 98 Location: Nederland

That would be a extra oscillator.

JovianPyx · Posted: Sat Sep 01, 2018 2:01 pm Post subject:

The only sub-oscillator I've seen is one using a flip-flop to do frequency divide by 2 from a pulse or square output of another VCO. This will pitch sweep when the driving VCO is pitch swept, but it cannot sweep by itself. This type of sub-oscillator is not really an oscillator at all, though synth vernacular calls it that. It's also known as "sub-harmonic". A sub-oscillator of this type tracks the driving VCO perfectly.

To separately sweep, you will need to use a VCO that can reach the low pitches you want. Unlike the flip-flop method, using this additionall VCO method, the bass oscillator will track only as well as it is tuned and calibrated.