Dynacomp mods for more brightness?

[oakst8]

Hi all,

I recently picked up a dynacomp (not vintage or RI) with the Monte Allums mod. I did not do the mod myself. The pedal adds a lovely warmth and thickness when played alone, but in a band setting, I find that the fatter low end and loss of highs is making my tone way too muddy.

This led me to decide that I need a more transparent compressor. I was about to order the BYOC Opticomp, but it's out of stock at the moment. So, in the meantime, I'm wondering if anyone has ideas on how I could mod the dynacomp to experiment with bringing back some of the brightness. I'm not using the pedal much at the moment, so I'm willing to take on a reasonable amount of risk in tinkering with it. Plus, every tinkering project leaves me a little less ignorant when it's done. 

Please note that, while I can follow directions ok, my knowledge of theory is highly limited. Clear and simple directions are appreciated.

Anyone familiar enough with this circuit to make any suggestions?

[Mark Hammer]

Almost all single-band compressors have the effect of seeming to dull the top end.

there are multiple ways around this challenge.  One is to blend some clean signal with the compressed.  Go check out the BYOC 5-knob compressor for some ideas.

[petemoore]

  Turn it into a ROSS compressor [uses the same board but has some missing LP filter compnents compared to DYNA.
  Something in-between is where mine ended up, can't remember exactly byt he Dyna was dull, so I lifted some of the LP Filtering while looking at DYna/Ross schematics.

[JDoyle]

Replace the .001uF cap on the output of the CA3080, connected to pin 6 and parallel with the 150k resistor, with a 500pF or 680pF cap (or better yet don't replace the original cap, just tack on caps parallel to it on the board, start with .01uF and work down to .0001uF), each move down will raise the output of the highs.

Keep in mind though that this change will most likely result in higher noise as that cap is there to both limit the bandwidth of the CA3080, but more importantly is a part of a 'quasi-companding' scheme where the highs are boosted in the 3080 and then cut after.

Any additional hiss/noise can almost assuredly be brought back down but requires changing another cap - multiply the value of your new cap by 10 and replace the cap parallel to the 15k resistor on the positive input of the 3080 with that value.

I make no guarantees as to the quality of this mod as I've never done it, but theorhetically at least - it should work as you want.

Regards,

Jay Doyle

[oakst8]

Jay,

Any chance you can help me locate the parts you referenced. I don't see anything that looks like the 3080's I found searching on google (perhaps changed in the Allums mod?), and I obviously want to start from the right place and swap the right parts.



Thanks!

[ppatchmods]

the 3080 chip is under one of the pots. be extremely careful when bending the pot back, as to not break it off!