[sdiy] favorite adsr?

[Stewart Pye]

Hi Dan,

To my knowledge it is the ability to charge/discharge the capacitor 
which determines how fast the EG is. Here is my thoughts on the topic. 
Someone please correct me if they are flawed...

If you had a common emitter  transistor arrangement  for the attach 
phase resistor the charging time would be dependant on the collector 
transistor, and I've seen this type of circuit using a 1k pullup 
(collector) resistor. However if you had whatever logic necessary 
feeding an emitter follower transistor then you could get much faster 
charge (attack) times.

If you are using logic gates then the charge rate is determined by the 
output current ability of the device used. In the EG design that I 
posted  a schematic of  a few weeks ago I ended up putting 3 CMOS 
inverter in parallel for the attack phase. I have not tested it though. 
After doing that I decided to use an AVR microcontroller for the logic, 
and have that driving charge/discharge transistors.

The above may not have shed much light on your question. Basically, if 
whatever is charging the timing capacitor is not capable of providing 
sufficient current, then the Attack may not be as fast as you would like.


Regards,
Stewart.


Dan Snazelle wrote:
>
> i am going to be testing out ADSR'S all weekend and i have heard (maybe wrongly) that transistor based ADSR's are quicker/snappier. 
>
> is this true? any recommendations on circuits to try?
>
> thanks
>
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