Hi Joe - thanks for quick reply.
I'm using OEP and want to try various DOA's including JLM Hybrid/2520/1731/990
I'm contemplating putting a Hi/Lo ratio switch and it says on attached jpg use low ratio parts but fit jumper to high ratio
So would i omit Rload and put in place of Rf 27k resistor, and for filter of 40Hz and 80Hz i would have cap values:
Hi Joe - thanks for quick reply.
I'm using OEP and want to try various DOA's including JLM Hybrid/2520/1731/990
I'm contemplating putting a Hi/Lo ratio switch and it says on attached jpg use low ratio parts but fit jumper to high ratio
So would i omit Rload and put in place of Rf 27k resistor, and for filter of 40Hz and 80Hz i would have cap values:
ps forgot to ask - do i still fit CLoad - i'd imagine i do
Yes fit CLoad it will not effect the HPF function and it needed at the opamp input so it is stable while switching HPF.
Usually you would leave the 68nF permanently inline and switch a 68nF - 82nF or 10uF across it and have 1Meg resistor across any open switch contacts to minimise pops.
Hi Joe - where do you get 10uF non polar caps from? RS used to do them but i cant find any reasonably priced ones on ebay?
Do they have to be non polar?
mikeyb wrote:Hi Joe - where do you get 10uF non polar caps from? RS used to do them but i cant find any reasonably priced ones on ebay?
Do they have to be non polar?
Cheers
mikeyb
Since your Rload is 27k you could use a 1uF (5.5Hz) to 2u2 (2.7Hz) poly or mkt cap instead.
We keep 10uF 25v Non Polar in stock and can add them into a order if asked for at the time of ordering.