just a question..

[rx5]

do n-Jfets sound like tubes in any way??  

jfet(2n5458)     and tube (12AX7).....

plan to use them as output buffers.... :roll:
thanks...


-Ralph

[aron]

I think they do in a way.

But you can't expect to just throw them into a circuit and expect them to sound like a tube.

Take a look at the schematics that have used JFETs over the years and see how others have used them.

[Paul Perry (Frostwave)]

Aron is right, I use a jfet as a source follower buffer inside a filter that I make, but it has unity gain & virtually no distortion at all, (same as a cathode follower) so, there is a buffer config that has no 'tone' of its own, valve OR fet!

[Ge_Whiz]

One of the more useful comparisons between JFETs and valves is that when a JFET is driven hard, it produces mainly second harmonic distortion, whereas bipolar transistors produce a wide range of harmonics, some unmusical. This can be clearly seen when monitoring the output of the 'Blue Magic' on a 'scope.

[Doug H]

Aron is right, I use a jfet as a source follower buffer inside a filter that I make, but it has unity gain & virtually no distortion at all, (same as a cathode follower) so, there is a buffer config that has no 'tone' of its own, valve OR fet!

In general I find this true. However, I can hear a difference between a JFET and BJT buffer in a 9v circuit. It's subtle but usually I prefer the BJT because it sounds "clearer" to me. I suspect it is because it can drive more current.

Doug

[Doug H]

Aron is right, I use a jfet as a source follower buffer inside a filter that I make, but it has unity gain & virtually no distortion at all, (same as a cathode follower) so, there is a buffer config that has no 'tone' of its own, valve OR fet!

In general I find this true. However, I can hear a difference between a JFET and BJT buffer in a 9v circuit. It's subtle but usually I prefer the BJT because it sounds "clearer" to me. I suspect it is because it can drive more current.

Doug