Orange squeezer - Bass mods-Need help

[liagasg]

http://www.tonepad.com/project.asp?id=5
I want to build this compressor for a friend. He plays bass.
The mods say to replace 2 capacitors.
The capacitor connected to the diode is pretty obvious.

But, can you help me identify the output capacitor 4.7uF which should be replaced with a 1uF?
Which one is that?
Here is the layout
http://www.tonepad.com/getFile.asp?id=11

[Mike Burgundy]

IC numbers on the schem and on the layout differ - the 4558 is a dual opamp, but you're only using one. Opamp "A" (pins 1,2 and 3, as per schem) is not used. Opamp "B" (pins 7,6,and 5 as per layout) is used instead - find the 4.7uF that is connected to pin 5 on one end, and to the 10k level pot on the other, that's the one.

[Renegadrian]

yes ony one half of the IC is used - I use the OS on bass stock and it works good!

[vendettav]

hey guys planning to build this here as well. for guitar, I have a TL071. giving the OS uses half of 4558 could i put TL071 instead? wouldi need to change anything in there? or how would i wire it??

[Mike Burgundy]

pinout is different (google for datasheets on 4558, TL072 and 071 and compare - 4558 and 072 are interchangeable, 071 isn't - single opamp instead of dual)
The layout in the tonepad file won't work for that - you'll have to make your own. Aside from that it'll be just fine. Just make sure all inputs, outputs and power connections match up.

[vendettav]

thanx, will do it

[liagasg]

Thanks for the feedback.