74LS90 replacement

[Bill Layer]

Hi Plinio,

>Instead of using these chips that generate a given amount of steps, 
>Why not make an LFO with sweveral waveform out (like noise, saw, triangle,
>[sine, square,] and their inverses) and instead of adding step out, add a
>couple sample and hold circuits that you could set up so that you can get
>any number of steps up from a sawtooth (up or down), or ascending
>decending steps from tri or sine, or random from noise. 

This is exactly the way it is handled in my EML-200. The 200's LFO produces
tri, pulse, sine and noise at the same freqs. This is then coupled to the
sample-and hold circuit for the effect you describe... The output of the
sample-and-hold fires the VCO. Done right, it almost seems like a crude
sequencer. (I guess it is...)

I wouldn't say this is unreasonably complicated, but then again, I wouldn't
say I understand the 200 very well either.


Bill Layer
Sales Technician
<b.layer at vikingelectronics.com>

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