[sdiy] Simple MIDI-syncable LFO...?

[Blandon Ray]

> Yes John, a simple 180 degree inversion of phase of an LFO is quite trivial
> indeed (one opamp and two resistors), but that only works with analog LFO
> signals.  Unfortunately, the LFO's in the Electrix "MO-FX" effect unit that Blandon
> mentioned are software-generated LFO's, and these soft LFO signals don't even
> get turned into analog voltages before being routed to "real" VCA's and
> filters, etc..    The MO-FX doesn't have any VCA's or filters, etc. -- it just has
> a DSP chip.  It's all done in the virtual realm -- both the creation of the
> LFO wave, and all the signal modulation that it controls.  Therefore, the only
> way to invert that LFO output would be to disassemble, reverse-engineer,
> rewrite, and reassemble the FO-FX's internal firmware code.  Of course, this should
> be child's play for richard at skydancer.com, since he's so well convinced that
> software LFO's are so much easier and better than hardware LFO's.  For the
> other 99% of us, however...


Indeed... I'm not one of those who thinks "analogue=good,
digital=bad," but the plain truth is, I know zero about
microcontroller programming, and marginally > 0 about analogue
hardware. It's sure to be a learning experience either way.

In fairness, it also occurred to me that since I own a PAiA MIDI2CV8,
which has a MIDI/Sync mode, I could just download the source and try
to modify it to do what I want. But here again, learning 8051 assembly
isn't high on my list of things to do, and I'd have to buy an EPROM
burner, and I couldn't give out the modified source without John
Simonton's OK, and so on.

Then again, for those of you who already make MIDI/CV interfaces that
run on microcontrollers, if you felt like incorporating this feature
into your product I could guarantee you at least one enthusiastic
buyer.

Squinting in the general direction of Cumbria,
Blandon
:)