A 3 band parametric eq from the Soviet Union, anyone? Electronic switching is removed and op amp is altered for normal 8 pin DIP package which replaces the odd dual op amp 14 pin DIP package.
As for R28 which is connecting across the output of the last op amp and ground, the schematic simply says "100". Could be iether 100 ohm or 100k but 100 ohm seems a bit low?
Upsate 260712. R28 confirmed to be 100k.
R28 measures as 96kOhms on the one I have. So they probably meant 100k. Thanks for the diagrams :)
ReplyDeleteThanks for the info! Will add that resistor value.
DeleteHey fuzzhead... would you be interested in doing the Boss PQ-4 Parametric Equalizer... http://www.synthdiy.com/files/2007/boss_pq-4.png
ReplyDeleteThanks for the schematic. I will hopefully do that one at some point!
DeleteFor Lell ep russian power suply 9V AC or DC ? Thenk 's .
ReplyDeleteYou can verify this one. I used 2N5088's and RC4558's. Very nice sounding EQ, and can get an exceptional cocked wah tone if you are into that
ReplyDeletealso, forgot to add, i used a 100k resistor at R28
DeleteCool! Thanks for verifyin. Pretty certain R28 is 100k by now.
DeleteI'll tag it and update the layout ASAP.