If you wish I can test them for you, but you should be able to find somebody much closer to your place
This fellow at EBAY is selling reliable real TOSHIBAs.
I got the set of four.
He also has matched sets of V spec 170 and 74.
What would one use the V spec FETs for?
Toshiba 2SJ74 BL 2SK170 BL matched JFETs for MC /Line Pre Amp - 4 Pair +-0.1ma | eBay
I got the set of four.
He also has matched sets of V spec 170 and 74.
What would one use the V spec FETs for?
Toshiba 2SJ74 BL 2SK170 BL matched JFETs for MC /Line Pre Amp - 4 Pair +-0.1ma | eBay
yes correct, these look like real JFET's from Toshiba, the shape is good and the stripe is in the middle.
Where did you source them?
Walter
they only got 10 pairs left, so I bought all of it yesterday
2sk170 verification
Hi there,
I received this few days ago, from ebay, so I had no time to measure them (yet), and considering price they have slim chances to be genuine, but they "look" decent, including stripe few posts earlier (edit: I have rechecked, stripe is not in the middle, so there may be some concern).
Until they are checked (well, with my limited resources and knowledge, I could use 9V battery to measure Idss, and maybe find someone with dual 10V PSU for voltage check), what do you think, based on pictures?
Normally, I buy from member alweit, for any project that has importance
Photos have been taken with mobile phone so quality is not the best, sorry.
Thanks for the opinion.
T.
Hi there,
I received this few days ago, from ebay, so I had no time to measure them (yet), and considering price they have slim chances to be genuine, but they "look" decent, including stripe few posts earlier (edit: I have rechecked, stripe is not in the middle, so there may be some concern).
Until they are checked (well, with my limited resources and knowledge, I could use 9V battery to measure Idss, and maybe find someone with dual 10V PSU for voltage check), what do you think, based on pictures?
Normally, I buy from member alweit, for any project that has importance
Photos have been taken with mobile phone so quality is not the best, sorry.
Thanks for the opinion.
T.
Attachments
Last edited:
It's Toshiba jfet crisis
Could you ask seller about refound and send you money back ?
Best regards
It's Toshiba jfet crisis
Could you ask seller about refound and send you money back ?
Best regards
, I do not want to be misunderstood, I have bought those with fair expectations, and paid adequate price .Playing with those (in terms of measurement is significantly cheaper then with trusted ones.
Just, regardless of price, they look to good (overall look, printing..)
I'll measure them, (well, in a way, again,limited resources) and get back to seller, having in mind refund is low on my list of priorities.
Thanks,
T.
here are some more photos
Attachments
Last edited:
Playing with those (in terms of measurement is significantly cheaper then with trusted ones.
Just, regardless of price, they look to good (overall look, printing..)
I'll measure them, (well, in a way, again,limited resources) and get back to seller, having in mind refund is low on my list of priorities.
Thanks,
T.
here are some more photos
Sadly this is false jfets business.
Buy from them and this fake market grow more and more
with perfectionised cosmetic copy's...what is your write feedback on this Ebay seller transaction ?
DiyAudio Store, Mouser , Farnell and all official components distributors that you buy quality at normal price that way to go imho.
Probably not very cheap but many components are affordable.
For 50 € you get free shipping.
Have a nice day
Sadly this is false jfets business.
Buy from them and this fake market grow more and more
with perfectionised cosmetic copy's...what is your write feedback on this Ebay seller transaction ?
DiyAudio Store, Mouser , Farnell and all official components distributors that you buy quality at normal price that way to go imho.
Probably not very cheap but many components are affordable.
For 50 € you get free shipping.
Have a nice day
well someone has to buy, TEST, and write (bad or positive) review. And that is what I was talking about when noted that money doesn't come first.
Speaking (badly) with no grounds about someone (fake components seller) doesn't make us better then them.
Normally, for components purchase, every suggestion (recommendation) has to go to official store of forum, than members, then recognized independent sellers/traders and so on.. I does not need to be mentioned that every part of importance (or maybe just - every part) has to come with background.
If I manage to make the test in reasonable time, I'll post results, and that is my goal, even contribution, if I may say so.
BR,
t.
Don't worry this guys know what they do...
if they write 2SJ74 is not by hazard choice.
Waste of people's precious time and money.
Honesty seller don't propose unknow source transistors.
Have fun
Hi there,
I received this few days ago, from ebay, so I had no time to measure them (yet), and considering price they have slim chances to be genuine, but they "look" decent, including stripe few posts earlier (edit: I have rechecked, stripe is not in the middle, so there may be some concern).
Until they are checked (well, with my limited resources and knowledge, I could use 9V battery to measure Idss, and maybe find someone with dual 10V PSU for voltage check), what do you think, based on pictures?
Normally, I buy from member alweit, for any project that has importance
Photos have been taken with mobile phone so quality is not the best, sorry.
Thanks for the opinion.
T.
Fakes indeed.
Look at the font: the '1' must be just a straight line, with no 'rooftop' on it. The '7' should be slightly bent.
The stripe on top should be in the middle.
Sadly this is false jfets business.
Buy from them and this fake market grow more and more
with perfectionised cosmetic copy's...what is your write feedback on this Ebay seller transaction ?
DiyAudio Store, Mouser , Farnell and all official components distributors that you buy quality at normal price that way to go imho.
Probably not very cheap but many components are affordable.
For 50 € you get free shipping.
Have a nice day
I'm not sure they are fakes and I'm not sure your attitude is right.
I have seen a lot of genuine devices with very different writing. Also, genuine K170 are not that rare - yet. Very different story for J74.
Official components distributors don't sell K170/J74 - so not an option.
The LSK170/LSJ74 from the diyAudio store are not Toshiba K170/J74 (lower Yfs, higher noise), and as far as I know no free shipping from the diyAudio store.
Reality is a bit more complex than you think.
Cheers,
Nic
You are not sure... well difference between us i am sure about jfets.
Noting complex in simple reality of semiconductor's production for fake market.
So many Diyers get problems in his amp's builds beacause.
From Wikipedia :
To counterfeit means to imitate something. Counterfeit products are fakes or unauthorised replicas of the real product. Counterfeit products are often produced with the intent to take advantage of the superior value of the imitated product. The word counterfeit frequently describes both the forgeries of currency and documents, as well as the imitations of clothing, handbags, shoes, pharmaceuticals, aviation and automobile parts, watches, electronics (both parts and finished products), software, works of art, toys, movies and any other type of products such as those.[1] Counterfeit products tend to have fake company logos and brands. In the case of goods, it results in patent infringement and/or trademark infringement. Counterfeit consumer products have a reputation for being lower quality (sometimes not working at all) and may even include toxic elements. This has resulted in the deaths of hundreds of thousands of people, due to automobile and aviation accidents, poisoning, or ceasing to take essential compounds (e.g. in the case a person takes non-working medicine).
Attitude
Ok LSK are not 100 % the same like Toshiba jfet's but pretty close:
http://www.diyaudio.com/forums/pass-labs/241642-mystery-sj74-jfets-10.html#post4705101
Hahaha photo ok i write you what the story
but please could you explain me meaning of this photos first ?
Attachments
Okay,
test time
Well, basic one, Idss measuring. So, by (many times repeated) on this forum I assembled a small jig.
Jumper is there to disconnect battery when switching components (anyway, it's late now, but, do I need to disconnect battery when swapping transistors ?).
My soldering isn't best, but will do.
Resistor is 100 OHM, power supply will be 9V battery, I need to find one.
O coruse, I will keep my eye on duration of each test, and voltage (that is what I am measuring) rise or fall.
Ill post results, and maybe (I am pretty sure it wont be needed) I'll assemble jig MK2 for Vp measuring and some calculations, but dual psu is slightly problem for me..
test time
Well, basic one, Idss measuring. So, by (many times repeated) on this forum I assembled a small jig.
Jumper is there to disconnect battery when switching components (anyway, it's late now, but, do I need to disconnect battery when swapping transistors ?).
My soldering isn't best, but will do.
Resistor is 100 OHM, power supply will be 9V battery, I need to find one
.O coruse, I will keep my eye on duration of each test, and voltage (that is what I am measuring) rise or fall.
Ill post results, and maybe (I am pretty sure it wont be needed) I'll assemble jig MK2 for Vp measuring and some calculations, but dual psu is slightly problem for me..
Attachments
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.