J-FET Question...?!?

[ANALOG GUY]

I searched many forums about parts for design preamp / riaa / poweramp, why most of people suggested me only J-FET, why didn't Vacuum Tube ?

Does many J-FET project of PASS & Solid state better-stability more than TUBE ?, Yes or No.

If money not problem for DIY, Which parts do you want to build your audio project ?

Regard
analog guy

[anatech]

Hi ANALOG GUY,
Tubes are alive and well. Check out the tubes forum. There are some under developement and several already built and tested.

For low noise applications, solid state parts have an advantage. That is why you will get more suggestions that way.

I have both. I like both. Start digging and building!

-Chris

[Miles Prower]

Originally posted by ANALOG GUY
I searched many forums about parts for design preamp / riaa / poweramp, why most of people suggested me only J-FET, why didn't Vacuum Tube ?

Does many J-FET project of PASS & Solid state better-stability more than TUBE ?, Yes or No.

If money not problem for DIY, Which parts do you want to build your audio project ?

Regard
analog guy

A major reason for that is due to the square law input characteristic of the JFET. It gives less harmonics, and harmonics that roll off with frequency faster than the 1.5 law of VTs, which, in turn, is better than the exponential input of BJTs. Stability really doesn't have anything to do with it since the gains of VTs and JFETs are comparable.