tonepad envelope filter

[aka_daz]

hey pps hoping to build tone pads auto wah (envelope filter) and can only source TI chips, from what I've heard they don't bias properly in this circuit. i don't understand biasing in the slightest, and was hoping sum 1 cud help me out and let me know which resistor(s) to change and what too

many thanks in advance pps

[aka_daz]

p.s. if anyone could explain biasing simply that would be appreciated

[chicago_mike]

Change R16 to a 100K trimmer and wire it as such. Now some reports have peeps still not getting the TI to work in U2 position, but 1 and 3 work.

Try to find RCA or SE 4066's. JAMPAK usually will mix them up.

I had the Morloey bass wah wich used all TI chips in a very similar circuit, but I havent tested it to see what voltages are on those chips.

[aka_daz]

i've managed to source some nec 4066' from an old beta max player,  does anyone know if these work? has anyone use nec's for this project?