ASM-1 up and running

Tony Clark clark at andrews.edu
Fri Oct 4 15:42:57 CEST 1996


>    One thing that has me stumped is that the with really low frequencies
> (like less than 1 hz), the output of the LFO seems to be asymetrical. On
> the triangle wave, the rising part takes a lot longer than the falling
> part. On the square wave, the voltage stays low for much longer than it
> stays high. I believe I just used a ceramic dip capacitor, could this be
> the problem ? Apparently it's discharging faster than it's charging at low
> frequencies. Also, although my LFO goes well up into the audio range, it
> stops oscillating when it gets below around .2 hz. Of course I'd like the
> LFO to do really slow sweeps. As far as I know I put the proper components
> in.
>   Anyone have any suggestions ?

   What you may be experiencing is just the design limitations of the 
LFO.  Although I would expect the LFO to be optimized for very low 
frequencies, from what you suggest, it sounds as if it was designed to 
serve not only as an LFO but as an additional audio oscillator.  In that 
kind of scheme, you're finding that below its optimal low frequency end, 
the charge/discharge currents become imbalanced.  Therefore you get the 
different rise/fall rates.

   Tony




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