Why use a 6SL7? That's not a good choice for a cathode follower- what you want there is high transconductance and reasonably high current. ECC88, D3a, ECC99, that sort of thing. There are some topological issues, too, but let's get the tube right first.
SY is correct about the 6SL7 not being the best tube for the job - but you have a MAJOR mistake in the low pass circuit.
You will only have the grid/cathode V (maybe 2V) across the 40k cathode follower R = microamps of current.
To make it work, even with 6SL7's - you will need to either elevate the grid like you have done in the hipass, or provide a negative supply to feed that 40k.
Regards, Allen
You will only have the grid/cathode V (maybe 2V) across the 40k cathode follower R = microamps of current.
To make it work, even with 6SL7's - you will need to either elevate the grid like you have done in the hipass, or provide a negative supply to feed that 40k.
Regards, Allen
Those are some of the topological issues. So is the dependence of the filter transfer characteristics on the source impedance.
I'll hold my tongue about using Sallen-Key.😀
I'll hold my tongue about using Sallen-Key.😀
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