[sdiy] sample and (infinite) hold

[mark verbos]

maybe you can impliment the S&H as part of the quantizer. If you are 
converting the CV into digital anyway, you could sampled and hold it in 
the digital domain, before you DA it again. It won't droop there.

Mark



Scott Juskiw wrote:

>> Infinite is a really long time...
>>
>> I've worked with some of that stuff,  and it's crucial that you 
>> follow the
>> right construction practices there,  and that you choose the proper 
>> type of
>> capacitor for your hold.
>>
>> What kind of a cap did you use?
>>
>> The stuff I built,  I used a dual FET as was done in something or 
>> other I ran
>> into at the time (ARP?  I forget),  but that was before FET-input op 
>> amps
>> became commonplace.  I don't know if they'd work or not,  but the use 
>> of them
>> seems to be pretty common.
>>
>> What kind of droop are you seeing and in what kind of a time frame?
>
>
> I'm using a polypropylene at the momen., I've tried polycarbonate, 
> polystyrene, they all droop eventually. The S&H output is fed to a 
> quantizer which sets the root key of a repeating sequence. After a 
> minute or so the output will droop so that the quantizer will knock 
> the sequence down a semitone. I'd like the sequence to stay in key for 
> 20 minutes, or 20 days, or the full length of a Klaus Schulze piece.
>