Is That Possible To Subtitute Mosfet With Jfet?

[Agung Kurniawan]

As i say. Is that possible?
Did this case will affect the whole think?

[PRR]

"Possible" sometimes, but does affect the whole think.

If you don't know how, probably best to get the right kind of part.

[Agung Kurniawan]

Aaahhhhh, i cant get any Mosfet from the lokal market.

[pinkjimiphoton]

imho yeah you can pretty much sub any transistor if you make sure to make accomodations with bias so it will fire up,
i have often used all kinds of "wrong" stuff to good effect. socket your transistors (i buy little 6 in line dip sockets and split 'em down the middle)
POWER DOWN between swaps,, and play with it to your hearts content. if you use trimmers or pots instead of resistors, you can really dial in a lot of useful linear sounds and sometimes some very WEIRd non linear ones... sometimes if you keep messing with something well past the point of cutoff, it will drop to audio range again and sound very ....ummm.. different. some may like it (i do) some may not.

they all sound a little different, but often times you can make some pretty drastic subs. jmo, ymmv
beware tho i am blissfully uncaring to let the magick smoke out in search of cool noises.
there's tonnes of info on biasing transitors out there on the forum.

rock on and have a blast dude

[bool]

Sometimes - and only sometimes - it's possible to sub an enhancement type mosfet with a darlington BJT. Of course you must look for mosfet Vgs - it must not be much different from twin PN drops of the darlington in order to bias properly etc.

In short, sometimes you can swap small often-used types like 2N7000 and BS170 with a MPSA13 or likes. (I guess that's the main point of interest to you). But the "mosfet tone" will be gone with the swap...

[pinkjimiphoton]

mosfet tone is kinda subjective tho, innit? depends (to my ear) more on the circuit topography and the peripherals associated with it than the transistors.
sorry, but i don't subscribe to the "it has to be this q" school of thought too much. i look at it like this... either it works, or doesn't, or it lets the magick smoke out. either way eventually something good can be gotten out of just about anything.
i mean, ideally, transistors of any kind shouldn't matter so much as their gain. we're not looking for linear response, we are looking to intentionally misbias stuff to get it to distort.
imho mosfets matter more tonally as clippers than amp stages, and i prefer them when i tinker to not be over the edge into hard clipping. right TO the edge is one thing, but once it clips...
and i know this is sacrilege to most...

a fuzzbox is a fuzzbox. i mean, once ya hit a square wave

ymmv. absolutely not all subs will work. but many will with no circuit modification. and remember, if looking to use as distortions, many mosfets and fets in general seem  to sound better when reverse biased. depends on how crazy you are, and how willing you are to play with what ya got.
i think with proper passive support damn near any semiconductor can be exploited tonefully.

jmo, ymmv