I should get French amplifier Filson 216 later today. Only schematic I can find is for Filson 215, I assume its more or less the same.
What I see from schematic is that input ECC83 has cathode grounded (?) and input resistor has been set to 27K. Probably at 1963. it was proper for phono carts those days.
I am thinking to replace 27K with 47K+100 to 200 pF parallel with resistor.
Also I cannot figure it out how RIAA here works, its not as passive eq, its not as feedback line.
Basically I am interested is it enough to put 47K+200pF on phono input (as suggested for my phono cart) and leave everything else as is?
Second, how RIAA here works?
What I see from schematic is that input ECC83 has cathode grounded (?) and input resistor has been set to 27K. Probably at 1963. it was proper for phono carts those days.
I am thinking to replace 27K with 47K+100 to 200 pF parallel with resistor.
Also I cannot figure it out how RIAA here works, its not as passive eq, its not as feedback line.
Basically I am interested is it enough to put 47K+200pF on phono input (as suggested for my phono cart) and leave everything else as is?
Second, how RIAA here works?
That looks like an early circuit designed for use with GE variable reluctance cartridges. Part of the RIAA EQ is accomplished by using the inductance of the coils in the cartridge. So, simply changing the parts at the RCA I/Ps is not sufficient.
This very thing was the subject of a recent AA thread.
This very thing was the subject of a recent AA thread.
So, simply changing the parts at the RCA I/Ps is not sufficient.
So I guess I will use other phono preamp with this amplifier.
Does not this 27k change tonality of sound?
Thanks both for answers!
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