Thank you! And the later ones are etched right? Just to be sure how etched vs printed look/feel like
Yes, later real ones were etched but with a curved leg on the "7".
Both of the pictures show etched 2sk170's. The top one is fake and the bottom was taken from "punkydawgs" eBay seller who is known to sell the real deal. I have purchased from him and the parts tested real.
The older real printed Toshiba's (like the ones you have) tend to look fuzzier with wider numerals, you most likely need a magnifying glass to see that it is printed. You don't come across many of those out in the wild so most won't need to identify them but as you have shown they do exist.
It's been over a year since I've hunted for any of these so things might have changed, but I still see many obvious fakes out there. If your looking for these try to go with a seller that has been vouched for. Many of the over seas sellers are skilled in the art of bait and switch. Showing pictures of the real thing and shipping you something else. I'm not saying all sellers, just some that I have used have done this. It's a roll of the dice and not worth the hassle.
This is how I see it:
Straight leg "7" printed = good (but rare), straight leg "7" etched = bad, curved leg "7" etched = first good clue that it is real
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My expensive toshiba j-fets stock I have bought from Spencer 10+ years ago ( bag of 100 for 80usd or so) have been exausted . I have tried to purchuase genue Toshiba j-fets at reasonable price (0.2-0.4eur/psc).Unfortunately china sells fakes and it cost 2 to 7 times more. I bought some for educational purposes. Then I have buy from 3 EUROPEN stores Germany, Italy and UK, with price about 2.5eur/psc and all of them was fake. Explanation from sellers was like " I am 69years old electronic engineer, i got those from company which went bankrput, i have measured them to be sure its performs 100%, why do you think its fake." this is exlanation from single seller.
Finaly i bought them in local audioshop (for desired 0.3eur/psc). Genue. i bought all what they had and reguested another 500-1000psc with condintion that they will ge it with same source. Now waiting answer.
high price for non exotics parts or fakely exotics ( some old speakers drivers, tube lamps is really exotics) are reason of loss of DIY spirit of audiophiles. its bad both for audiophile buyers and audiophile sellers (simple sellers jsut sell what they need to sell to get money-as this is primary target) I have really lost some great sound selling Black Gate caps which I bought 15 times cheaper than people want to buy from me. I also lost many great moments not building circuits because of excessive amount of toshiba j-fets in that circuits. I even disembled some of them (one dac had 20+ tightly matched sj74bl/sj170bl) because of that reason. so its happening exactly like in Black Gate case. Toshiba parts even have way mutch less narrow customer target than black gates. ant they are VERY ROBUST. even oscilations from dac did not kill input stage of xa200.5 which had input caps remooved.
There is no reason small signal toshiba J-fets have to be so expensive(power mosfter v-fets are used in multiple pararel configuratons in reality are used lot more)
so toshiba j-fets 1)are used in small qty in circuits( 2-6psc), 2) they are very robust and 3) there is not much circuits for diyers demand.
I would be largely surpsised if real anual (use in circit not buy and store in drawer) consumption for those jets is more than 1000-2000psc for the diyers. untill 2007 or so situation was normal- they costed extra comapring for other parts it but was quite widely available. a few circuits have come out , and 4-10 people in the world bought 80% of NOS jfets stock. still have a few hundreds of them but I switched to others circuits because can not get them for 1eur /psc .
a input stage transitor should not cost 10 times more than output stage transistor.
for the price of input pair of NOS toshiba on ebay you can buy 100 000uf of NOS power suply caps on ebay.
this makes them unusable in most circuits if any engineeering common sense is involved
sadly its loose-loose situation for everyone of us..
P.S. If i get extra j-fets for the same price i wills ell it for diy comunnity for the same price(0.3eur/psc). they will be surplus for me and no needed. a simple 9V 100ohm resistor setup matching could be done without any extra cost. so fingers crossed for all diyers.
Finaly i bought them in local audioshop (for desired 0.3eur/psc). Genue. i bought all what they had and reguested another 500-1000psc with condintion that they will ge it with same source. Now waiting answer.
high price for non exotics parts or fakely exotics ( some old speakers drivers, tube lamps is really exotics) are reason of loss of DIY spirit of audiophiles. its bad both for audiophile buyers and audiophile sellers (simple sellers jsut sell what they need to sell to get money-as this is primary target) I have really lost some great sound selling Black Gate caps which I bought 15 times cheaper than people want to buy from me. I also lost many great moments not building circuits because of excessive amount of toshiba j-fets in that circuits. I even disembled some of them (one dac had 20+ tightly matched sj74bl/sj170bl) because of that reason. so its happening exactly like in Black Gate case. Toshiba parts even have way mutch less narrow customer target than black gates. ant they are VERY ROBUST. even oscilations from dac did not kill input stage of xa200.5 which had input caps remooved.
There is no reason small signal toshiba J-fets have to be so expensive(power mosfter v-fets are used in multiple pararel configuratons in reality are used lot more)
so toshiba j-fets 1)are used in small qty in circuits( 2-6psc), 2) they are very robust and 3) there is not much circuits for diyers demand.
I would be largely surpsised if real anual (use in circit not buy and store in drawer) consumption for those jets is more than 1000-2000psc for the diyers. untill 2007 or so situation was normal- they costed extra comapring for other parts it but was quite widely available. a few circuits have come out , and 4-10 people in the world bought 80% of NOS jfets stock. still have a few hundreds of them but I switched to others circuits because can not get them for 1eur /psc .
a input stage transitor should not cost 10 times more than output stage transistor.
for the price of input pair of NOS toshiba on ebay you can buy 100 000uf of NOS power suply caps on ebay.
this makes them unusable in most circuits if any engineeering common sense is involved
sadly its loose-loose situation for everyone of us..
P.S. If i get extra j-fets for the same price i wills ell it for diy comunnity for the same price(0.3eur/psc). they will be surplus for me and no needed. a simple 9V 100ohm resistor setup matching could be done without any extra cost. so fingers crossed for all diyers.
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Reposting a well known helpful guide for other clues to authentic devices that I think I found in this thread, maybe way back.
nr12,
I would agree with Soundhappy. The one on right looks genuine. Can you say if the straight leg "7" is etched or printed?
I would like to know if Toshiba ever made (maybe very early on) a straight leg "7" that way etched.
Thanks
nr12,
I would agree with Soundhappy. The one on right looks genuine. Can you say if the straight leg "7" is etched or printed?
I would like to know if Toshiba ever made (maybe very early on) a straight leg "7" that way etched.
Thanks
Attachments
Matched JS74's
Hello balanced RCA cables!
I had several small deals for matched JS74's and JSK170 with NicMac whom you will find on this same thread. He is an absolutely serious person and his JFET's are original Tosh's. His prices are fair for the effort he is spending into selection and matching.
NicMac is EU/Italy and has no problems dealing in €'s.
Hello balanced RCA cables!
I had several small deals for matched JS74's and JSK170 with NicMac whom you will find on this same thread. He is an absolutely serious person and his JFET's are original Tosh's. His prices are fair for the effort he is spending into selection and matching.
NicMac is EU/Italy and has no problems dealing in €'s.
Thanks you Mr. Pass 
for excellent news!