Replacement For Toshiba 2SK170/2SJ74

diyAudio Chief Moderator
Joined 2002
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diyAudio Chief Moderator
Joined 2002
Paid Member
Quite right. 2SK117 or alike parts are a useful alternative depending on the situation. That is why I opted in the DCG3 line preamp for a then forgotten and not at all sought after NOS NEC dual monolithic with much alike to 2SK117 characteristics. Its a matter of balancing enough performance vs viability for a repeatable project. Alas, not anymore, prices went up and fakes appeared. Better go even with adapters and known quality Toshiba SMD from reliable mega stockists these days.
 
B&D Ent Toshibas

I've bought 8 pairs from Bdent: 2SK170BL+2SJ74BL

While they're not matched sets, i've read elsewhere that they're pretty close and genuine. Should I be concerned about the different ranking(?) number or batch # between each complementary part. The J74 are 8H & the K170 are 8G.

Of course one can plot curves for each JFet but then varying room temps or even blowing on them while doing measurements is a concern; and the testing won't be accurate.

Advise on the photos taken?

https://i.imgur.com/0m8707d.jpg

sBgsDgk.jpg


One thing others have not mentioned is the left over flux at the top of the leads (see in photo). Of the 3 legs you can see the brown flux which i'm not sure if the 'FAKE' ones would have the same assembly process? Just something to consider about when looking at fakes.

CY135OR.jpg


Back side has the round molding mark.

bwbCNIB.jpg


Top side molding mark. Also the line that others mentioned is the molding seam.
 
Greetings to all experts,
I found 8 NOS 2sk170GR on the shelf (bought in 2011 for 1 EUR from ELFA :D) - I measured Idss with 9V PSU - 4 is in the range of 4-5.5 mA and 4 is in the range of 6 -6.5 mA. Can I use the last 4 to say B1 or ACA instead of BL or Idss is too low?

tnx
 

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