JH's VCO

[mbartkow at ET.PUT.Poznan.PL]

Hi all

I have been just playing with the thyristor-based VCO Juergen posted
some time ago (well, just the core Q1-Q8, J1,J2 and U3, I don't need
the interclock prevention circuitry yet). This circuit promises a high
scale range due to the high speed of the thyristor switching. I intended
to use this VCO in a wavetable oscilator, so I needed a good ultrasonic
range operation (to be scaled down by the sample counter). 

I observed accurate tuning within only about 4-5 octaves, and my VCO 
goes significantly flat over about 30kHz. I reckon this might be due to 
the general purpose transistors I used.

My question is whether anybody tried this out and achieved wider tracking
range, especially in the high frequency range ? Do you use some fast swi-
tching transistors ?

regards,

mb


--

Maciej Bartkowiak, PhD
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