I see that Bugg now has a board for a Formula 5F6 for sale - "Tweed Man". Is there a Jfet suitable as an MPF4393 alternative? I looked and they are stupid expensive! Is that really what is in a Formula 5F6?
Well to be fair they are sold on Ebay...and I just ordered some......
If I am correct the J201 and 2N5457 can work
Avoid anything that is out of production being sold on eBay like the proverbial plague. Chances are you're just going to get fakes. Get SMD JFET's instead with adapter boards. A bit of a pain to solder, but still less of a pain then dealing with fakes.
there is an ebay seller selling 20 of the smd 4393 for stupid cheap(ie~$6) shipped and the adapter boards are cheap by the sheet on ebay or from paul(chromsphere) at diygp. they are far more reliable and consistent, I had originally bought them for the Sabbra Cadabbra, but they work in all kinda builds. Really Neutral sounding as well, not bright, but not dark either, VGS(off) hovers around -1.30V in mine