Non-polarized caps necessary here? OS+++

[lars-musik]

Hello fellows,

I'd like to try this compressor. Could you tell me whether non-polarized caps are mandatory for C10 and C11? I can't deduce it from the schematic. As everything I build ends up in a 1590a non polarized 4u7 might be a knock-out criteria.

[Kipper4]

Hey Lars.
How are you?
If you google OS Schematic you will see that lots of them do not state any non polar electrolytic caps.

[samhay]

The top of C10 and C11 are at half supply (op-amp output), while the 'bottom' are DC coupled to ground via R16 and R17.
I would use polarised caps...

[Groovenut]

Lars,

If you are going to use a pcb, maybe try these http://www.mouser.com/ProductDetail/AVX/12063C475KAT2A/?qs=sGAEpiMZZMvsSlwiRhF8ql%252bl%252bLkmsJv1XbO9WDNGNqo%3d

They are 1206 size so pretty close to .1" lead spacing (they make them in 0805 as well if you want smaller). Since those caps are in the side chain, mlcc's would probably be just fine.

Just an idea

Law

[amptramp]

Polarized caps should be OK for this.  The top of the cap is held above Vcc/2 for C10 and at Vcc/2 for C11.  R16 and R17 hold the bottom of the caps at zero volts in a quiescent state but as soon as signal is added, the diodes pile electrons up on the anode, forcing it negative and the only thing driving the bottom of the capacitor positive would be leakage through the germanium diodes, which should be totally swamped by R16 and R17.

[lars-musik]

Thanks to you all. The very answers I wanted to get. Rich, I am fine, although quite busy at the moment.

Not sure when I'll get to etching and populating the board.

If somebody wants to have a go at it before me, here's my preliminary layout. Two large jumper cables unfortunately but 1590a-worthy. I created a pattern for the caps in question that'll allow for smd (Lawrence, I got some 4u7 smds here but they are huge....) and through hole.