[sdiy] How Many Oscillators?

[Richard Wentk]

At 08:51 26/09/2003 -0400, you wrote:
>Dear Friends,
>     I am planning a modular synthesizer and drawing some functional 
> diagrams. In the process I am trying to determine how many oscillators 
> would be practical. I have seen common synthesizers with two and three 
> oscillators each with a few different choices of waveform.
>
>In terms of practicality versus sound shaping properties is it unrealistic 
>to design around six or even eight oscillators per voice?

It depends what your main interest is. If you want that fat analogue sound 
then there's not a huge point in producing 8 VCOS/voice unless you have 
more money than God, a lot of real estate, your own electricity substation 
and a band of dedicated helpers. An 8 VCO voice board/system is a BIG 
project, and expensive and time-consuming too. Not to mention being an 
interesting challenge from the point of view of automated tuning (you 
weren't planning to use trimmers, were you?) and general maintenance.

For a poly instrument I'd say that more than three would definitely be 
overkill. Programming more can get to be a pain, and after a while you can 
actually have too much fatness. Beyond a certain level of complexity chords 
stop working. There's just too much going on and the sound tends to mush 
into synthy gloop.

For additive and FM then you really can't have enough oscillators, BUT they 
have to have super-stable tuning, otherwise the whole sound falls apart 
again. A complex FM patch with mistuned drifting oscillators is a painful, 
*painful* thing. :-)

For generic mono sound design and occasional multitimbral sequencing, then 
8 oscillators in total would be a good point to aim for as a start. I'd 
make at least a couple of those digital wavetable oscillators just for 
variety. 8 is a good practical number, it's not too expensive and not too 
hard to build, and once you've gotten that far you can maybe start thinking 
about a more complex design.

Richard