quick build report: So simple compressor

[snoof]

Just breadboarded this one (version 2), real nice subtle compression!!  It's gonna get boxed fer sure .  Are there any mods floating about to adjust the realease time on this puppy??  Not that it really needs it, it's very cool as-is, just would like to play around with it a bit...

http://aronnelson.com/gallery/album15 - perf and pcb layouts...

http://www.diystompboxes.com/smfforum/index.php?topic=51750.0 - schem in this thread...

Thanks to the folks that talked this one up, it convinced me to give it a go!

[markm]

I'm glad to see this one getting some attention.
puzzle87 did a Tremendous jod with the design.... it functions very well, relatively easy  to build and very quiet.
What more could one ask for?? 

[Mark Hammer]

Looks like C4 and R8 are the culprits for setting response time.  As C4 gets higher in value, both attack and decay times increase.  As R8 gets higher in value, it takes longer for C4 to discharge, providing longer release times.

[snoof]

thanks for the suggestions Mark!  So it appears that I could use a 1M pot wired as a var resistor in place of R8 to tweak it out.

[Mark Hammer]

Yes, but keep in mind that you don't want release time to get to fast.  Particularly when the control element - a MosFet in this case - is able to respond to every little bit of ripple in the control signal.  Make sure your minimum resistance is reasonably high.  Maybe a 100k resistor in series with a 1meg variable resistor is okay for starters.

[snoof]

Gotcha.  I was looking for longer as opposed to shorter release times, but if I were to leave the pot in the circuit, I'd def put in that 100k.

[petemoore]

  SPST could also be used to switch between cap [add a cap] values for C4, that and an adjustable R8 might make for being able to adjust the responses.

[Dragonfly]

  SPST could also be used to switch between cap [add a cap] values for C4, that and an adjustable R8 might make for being able to adjust the responses.

...or a rotary with different value caps...

[Mark Hammer]

  SPST could also be used to switch between cap [add a cap] values for C4, that and an adjustable R8 might make for being able to adjust the responses.

As long as you don't plan on switching in a live gigging situation.  Pops from reconnected "hanging" electrolytics can be pretty substantial.  I've been using the method you suggest for producing gross timing changes in my envelope-controlled filters for a while, and while it works, you pay a sonic "tax".  I don't gig and I never really play loud so the risk/tax is small.

[markm]

Some very interesting mod suggestions here for this one.....I may have to give 'em a try!