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[mark verbos]

There are fast photocell devices, something like Vactrols but from 
Signetics and homamatsu that would solve this problem for you. They 
almost as fast as an OTA, or at least I can't tell the difference.

mark



jbv wrote:

>harry,
>
>  
>
>>OTA might be more 'high tech' but also a lot harder to control. There is time
>>delay through the OTA (not much but in a feedback loop it could be enough
>>to notice)... OTA has limited signal handling capacity, high offset voltage
>>etc...
>>
>>Where the LED/Photocell might work just fine, and for maybe $.50 (usa)
>>
>>    
>>
>
>Do you mean that a LED/Photocell could respond efficiently
>to very fast envelope signals with different shapes (linear, log,
>dome...) ?
>This is not the experience I had with photocells which had a
>certain latency... but that was back in the late 70's... Perhaps
>did technology improve since...
>If that solution could work, that would be great, in terms of
>cost, design time and PCB room...
>
>Best,
>JB
>
>
>  
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