Rebot 2.5 question on 5pf

[iccaros]

So tossing out the 20% rule, the closest I could find to a 5pf was  a 3.5 with out waiting weeks on an order or paying more in shipping then in caps..

the question, the 5pf that is in parallel with the 510K resistor on the negative feedback circuit of second side of the opamp, should stabilize the NF and roll off anything above 64K about, changing to 3.5 put us around 94K still out of human hearing.. so would this destabilize the opamp for the design, or would any <10 PF cap do the trick with 5 being in the center design grab?

[MikeH]

Should be fine - I think I used a 10pf in mine... 

Also fyi - for really low pf caps, you can actually make them out of two pieces of insulated wire twisted together; I think I saw it in an Anderton book

[iccaros]

Should be fine - I think I used a 10pf in mine... 

Also fyi - for really low pf caps, you can actually make them out of two pieces of insulated wire twisted together; I think I saw it in an Anderton book

Thanks
I was showing my kids how to make caps with aluminum foil and wax paper..
but I was getting more than PF..

[Fp-www.Tonepad.com]

10pF is fine.
Fp

[iccaros]

10pF is fine.
Fp

Thanks... By the way  great boards.. I am putting two of them in an enclosure.. already have two people who want  a double rebot.. will be ordering more boards..