Fake 2SK30A transistors - I think

[Yazoo]

I've just received 20 (2S)K30ATM transistors from Tayda. I'm having a go at the Roland AP-7 and I need 8 matched transistors. I used the GEO Fet matcher but got unexpected values, ranging between -0.18 and -0.25 volts for VGS off. According to the datasheet, the minimum VGS should be -0.4 at 10 volts. I also tested another SK30A I already had and I got -0.8 volts. So it looks like I have got fakes. Is that correct?

In the meantime, I have 2N5457s on order from a UK supplier. Are these a reasonably close substitute?

Tayda have always been a good supplier in the past, so I'm hoping this is just a hiccup.

[njkmonty]

i had a similar issue   i dont thinks its intentional  however my tayda ones were dodgy

[pinkjimiphoton]

welcome to the wonderful world of jfets.  to get 8 matched ones i'd expect to have to buy a lot of 100 or more sadly.
i bought from polida on ebay, 200 of them, and got a bunch of matches for phasers, so maybe try them, or steve at smallbear. mouser too. most things can use a 2n5457 or j113 for a sub, but it depends on the circuit and how close the tolerances are i guess. good luck!!