[sdiy] Monosynth features poll

[Dave Kendall]

Once you have a sine Sub in an analogue patch, an easy way *might* be, 
a simple LP filter applied to the sine, which is then then mixed with 
the raw VCO output, let's say SAW in this case. I don't know what the 
optimum cutoff or dB/octave slope for the sine-sub filter should be, 
but a simple 6dB LPF might be a good start... That mix then gets sent 
to your next stage, VCF/VCA or what have you...
If we're being careful, a frequency-tracking (key CV?) VCA could be 
used in combination, to slightly increase the level of the overall 
patch with rising frequency, so that the perceived volume stays 
constant as the sub sine is attenuated with rising pitch.

FWIW, I've used this trick successfully in the DX7, and nowadays in the 
Kurzweil K2000 to warm up some high-harmonic "buzzy" sounds, although 
in both machines, I simply decreased the volume of the sub-sine and 
compensated with additional overall patch gain with rising frequency. 
Freq-tracking loudness is always available in the K2 and the DX, but in 
many patches, only one filter is available in the K2 due to its 
architecture, and the DX doesn't have any filters anyway....

The Kurzweils are all pretty serious beasties in terms of synthesis 
horsepower and flexibility.... google for a downloadable online .pdf 
manual for a K2000, K2600 or K2661, and then look at it's FUN 
(function) section. Pretty hard-core IMO.....

cheers,
Dave
(sadly ring mod-free at the moment, but have a CGS ring mod PCB waiting 
in the wings... ;-)





Interested to hear if you
On Jan 26, 2010, at 05:53, David G. Dixon wrote:

>> 7/ If adding a sub-osc, include a sine output (not just the usual
>> square), and a level control, and perhaps a way of rolling its volume
>> off as pitch increases. That Sub sine loses it's usefulness as pitch
>> rises, sometimes becoming unwanted at the top end of the keyboard.
>
> Is there an easy way to do this?  If so, can you point me to it?
> Thanks in advance!
>
> Oh, by the way, you forgot the ring mod!
>