:: mm pre phono ::

[dhengkoel]

Dear all:

Thanks for your comments ........

I revised my schematic ... and I will try it tomorrow ... I post the report as soon as possible ...

Regards: ragil.hastomo

[peranders]

Now it's looking better. Don't forget the 100nF in parallel with the big caps. Also skip the gate resistors, adds noise. Use them ONLY if you are having trouble unstability.

[hifidaddy]

Originally posted by dhengkoel
Dear all:

Thanks for your comments ........

I revised my schematic ... and I will try it tomorrow ... I post the report as soon as possible ...

Regards: ragil.hastomo

dhengkoel,

in your last schematic, you would overload Q2, because it must take several times nearly the full Idss of the input JFETs.

BTW, the 2SK30 is not happy when paralleling in phono input stages. I tried it. One is enough - if not take a 2SK170, as Werner already said.

BTW (2), the 2SK30 has low internal capacitances, and a very high output impedance. You do more harm with cascoding that input stage, than getting benefits, if at all.

So, please, make your circuit simpler. A single 2SK30 in the input, without cascode, that is enough.

regards,
Hartmut

[Jocko Homo]

Also skip the gate resistors, adds noise. Use them ONLY if you are having trouble unstability.

Wrong, wrong ,wrong,, wrong..........

Just add them and you won't have to worry about it. Or the noise.

Jocko