[sdiy] Level Shifting question

[Tony Allgood]

> 1. if I have a C.V. that is +/-1v  I would like to
shift it to 0-2v.  What do I call this in modular
synth terms?

Basically a simple mixer will do you here. Simply insert a fixed voltage
in one input and apply the signal to another input. Now adjust the level
of the fixed voltage to give you your level shift.

Of course, if what you want is a variable level shift without any manual
knob twiddling, then that is more difficult. You would have to extract
the negative average peak value and subtract that from the input signal.
Tricky.

> 2. if I have a C.V. with + and - voltage, I would like
to invert only the - voltage.  What do I call this in
modular synth terms?

A full wave rectifier, or an absolute circuit as mentioned in the
previous replies. An envelope follower may also do this too.

Regards,

Tony Allgood                       Penrith, Cumbria, England

Oakley Sound Systems                     www.oakleysound.com
Modular projects            www.oakleysound.com/projects.htm