EHX Attack Equalizer

[jaylow]

How about this one? Maybe modernize it too with NPNs?
http://i181.photobucket.com/albums/x12/Henrik_J_album/ATTACKEQ.jpg

[johnk]

i'd like to see that one too! that schematic has few resisto values missing but they can also be found here:
http://www.freeinfosociety.com/media/images/4117.gif







I was thinking about using a TL074 or LM324 but two 4558P's might be best since that's what the original has.  i'd use a ICL7660s to get the bipolar 9V supply for it. i'm sure that Mark could draw that one up pretty easily.

[johnk]

it appears that the schematic that I posted is running the 4558's at +9V only. the original uses a bipolor supply so instead of grounding pin 4 of the chips (as shown in that schemo) you actually run -(v to both 4558's pin 4, otherwise it appears to be correct.
rather than wait, i just made my own vero of it and built it up. i just need to wire it to the pots and test it now.

[johnk]

YAY! it works!

[jaylow]

Do you mind sharing?

[johnk]

well, it's a pretty large vero at 24 x 22  and it has four stand up resistors or it would had to have been even larger, but it works and sounds exactly like the original and follows the original schematic exactly too. the nice thing is, with the 7660S it runs on a 9V power supply as opposed to two 9V batteries.

[jaylow]

Nice! I'm gonna have to try this one out too.