Searching for them has given me results as cheap as ~$0.50 and as much as $29.99. If I wanted to build an M2x using these JFETs, what source can I trust?
It is almost certain that anything originating from Asia will be fake at this point in time. There may be the odd exception here and there, but for the large part this holds true.
The best option is to use the 'B' graded LSK170/LSJ74 which are intended as drop-in replacements for the now-obsolete Toshibas. They are available on the diyAudio store (the link is on the header of this page, or you can visit this link)
The best option is to use the 'B' graded LSK170/LSJ74 which are intended as drop-in replacements for the now-obsolete Toshibas. They are available on the diyAudio store (the link is on the header of this page, or you can visit this link)
Have some fun and read posts #1 thru #5 on the M2x thread. You'll find out that Mountain View, Tucson, Austin, and Norwood were included in your M2x PCB bundle, precisely so you would have several other options that don't require any Toshiba JFETs. This means you can build and listen to your M2x amplifier, at the same time you continue to search the earth for genuine Toshiba JFETs, . Who knows, you might end up liking one of those other options so much, that you stop looking for Toshibas entirely.
Sadly you can’t and you won’t find them. It’s worse than finding the Ark of the Covenant! People know this and make really good looking fakes, the are not even close to the real ones. Don’t waste your time or money.
I have a stash of roughly 150 pieces NOS Toshiba 2SK170/2SJ74BL that I aquired from trustworthy sources over the years. I have pre-measured them all to put them in groups of Idss, but honestly I couldn't convince myself yet to offer them here. When you need more information or images pls. contact me via PM.
To get an idea where I have been using them kindly refer to my private little website --> DIY - Original-Ton
To get an idea where I have been using them kindly refer to my private little website --> DIY - Original-Ton