Does anyone have a schematic for this thing? I have one and would like to do some mods to it. Months of net cruising haven't turned up any info on it at all. Please don't make me trace it out.....

It is ridiculous how many stompbox compressors use essentially the same circuit as is found in the MXR Dynacomp.  If you can't score a schem from anyone, describe the semiconductors it uses (i.e., part #s) and it may be possible to deduce how closely it does or doesn't resemble the Dynacomp.

The most typical mods for any compressor would be to add attack and/or decay controls to the envelope follower sidechain to alter the feel or smoothness.  Other than that, there isn't a helluva lot you can do.  Although, now that you got me thinking about it, I'm wondering if it is possible to tap the envelope-follower output, install a small mini-phone jack and have a pre-compression envelope signal available for duty.  One of the problems about compressors is that once you have them on, anything that is envelope-controlled becomes less responsive or dynamic.  If you tap the envelope signal from the compressor itself *before* compression is applied then you can have compression AND a responsive envelope.

(BTW, I used to live in Fredericton and Sackville, teaching at STU and Mt. A.  I miss the corn fritters at York's Family Diner in Perth-Andover.  If you've never been, go.)

Thanks for the reply Mark!
    Well, this comp doesn't seem to be a Dynacomp clone. It has a 16 pin chip labelled 13600DA, as well as a 4558 and 3 2sc945 transistors. All caps are either electrolytic or film. It also has true bypass implemented thru a funky dpdt switch with a lil circuit board on the side for the connections.
      What I'd like to do is be able to mess with the attack time, and I'd like to add an LED to give a rough idea of how much squash I'm getting. I don't use any dynamics-dependant effects after the compressor so that's not a problem. I do have plans to build a version of Scott Swartz's Super-Tron which has provisions to keep the sidechain seperate from the signal path so I know what you're talking about there.
      We don't get up Perth-Andover way much but I'll definitely keep those corn fritters in mind next time we're gigging up that way


                   -  Dave

I guess at least one half of the LM13600 is beig used as a VCA.
There ar plenty of compressors that use CA3080s as the active elemnt, this might help as the CA3080 is an OTA (operational transconductance amplifier) and the 13600 is two OTAs with buffers.

You can find a schematic at:

www.anubics.com

enjoy, analogguru

Thank you analogguru! The envelope detector looks pretty much like the Dyna-Comp as Mr. Hammer surmised.