linearly decreasing gain with frequency

Audioguru

Joined Dec 20, 2007
11,248
I have never been to your country so I do not know which Fet-input opamps are popular there. There are hundreds of them available over here.

Why don't you try using just a single Jfet?
 

Audioguru

Joined Dec 20, 2007
11,248
A CD4007 does not have a Jfet, it has Mosfets. It will be difficult to bias it into a linear amplifier with a high input impedance. It needs negative feedback to bias it correctly but negative feedback results in an inverting amplifier with a low input impedance.
 

Thread Starter

fez

Joined Dec 6, 2009
47
Well, those are the ones I've already studied, not JFETs.

Feel free to throw some JFET names my way, guess I'll have to look into their working as well.
 

Audioguru

Joined Dec 20, 2007
11,248
The CD4007 Mosfets are very non-linear which might be bad or might make some interesting "fuzz" in an electric guitar preamp.

Common Jfets are 2N5457, 2N5458 and 2N5459. Also 2N5484, 2N5485 and 2N5486.
Their currents are in fairly narrow ranges.

A 2N3819 Jfet has its current in a very wide range so a linear circuit using one will need to be adjusted.
 
Top