VCO +- output, was [sdiy]linearize OTA for VCF?

[Scott Bernardi]

The sequencer only needs to cover a typical frequency spread within a sequence,
not the whole range of a VCO. -10 to +10v is 20 octaves!  5 octaves should be
plenty (0 to 5v), then you can also use the initial frequency control on your
VCO to set it to the range you want.
My original 16 step sequencer used 10 turn pots to set the pitch. But they're
expensive unless you can get them surplus (which is what I did, back in 1980).

"Benjamin M. Woenig" wrote:

> I have some similar questions relating to scaling and offset
> voltages within a modular system.
>
> I am building an(other!) analogue sequencer at the moment, and I am
> wondering
> what CV ranges I should have on the summed outputs for each channel.
> Roland equipment (like the SH101, 303 etc), appears to accept 0 to +7V
> for pitch CV and +5V (or greater) for gate signals. Most modular equipment
> I have seen has -10 to +10 CV range. I would think that a pot on a sequencer
> step sweeping the entire 20V range would be too "touchy" to get a precise
> pitch. What is the minimum voltage to trigger a MOTM envelope generator?
> +5V? +10V?
>
> Since I will be using my sequencer with Roland, Korg, Moog, and MOTM
> synths, would it be best if I had a switch to change the CV outputs from
> either 0 to +5V (for Roland gear), and -10V to +10V with a range pot so
> this could be easily scaled for the other gear?
>
> ~ben

--
Scott Bernardi
sbernardi at home.net