While they last...

They provisoned a $ 10.32 refund.
I rejected this.
No response at all.
I think, they just wait now, while negotiation time is finished.
The whole situation resembles to the judgement procedure in Hungarian film, A Tanú.
The Witness (1969 Hungarian film) - Wikipedia
"Excuse me, comerad Virág, but this is the judgement."
Tanu - Elnezest Virag elvtars ez az itelet.... - YouTube

My suggestion is, they can keep this money, for that unfortunate event if Mr. Jack Ma dies, they can buy a wreath on my behalf.
 
Got my random unmatched THF-51S pair from Tomoaki san.
Big pins a bit rusty but overall everything + package is top notch.
Tryed to curve trace with DCA75.
This tool is not for big transistors like this but this is what I have.

What DCA75 shows when I test them:

№1
N-Ch JFET
Vgs(off)=-3.30V at Id=5.0µA
Vgs(on)=-1.91V at Id=5.00mA
gfs=28.0mA/V at Id=3.0mA to 5.0mA
Idss>12.00mA at Vds=0.01V
Rds(on)<1.0Ω at Id=5.0mA and Vgs=0.0V

№2
N-Ch JFET
Vgs(off)=-3.36V at Id=5.0µA
Vgs(on)=-1.95V at Id=5.00mA
gfs=25.3mA/V at Id=3.0mA to 5.0mA
Idss>12.00mA at Vds=0.01V
Rds(on)<1.0Ω at Id=5.0mA and Vgs=0.0V
 

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I would say those are fairly well matched parts!
I have a pair of similarly unmatched parts (THF-51S), and another pair of roughly matched parts. Currently buried in the first round of Sony VFET evaluation, but things are going really well so far. Much anticipation about what Papa has in store for the larger SITs.
 
I got these from "Tomo" and they looks nice.
Don't think they are mathed but will try DCR75 and check.
The AA-battery is just for size comparation.....as they are quite large transistors.
 

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before the weekend I found a sites with 2SK183 hockey pucks and also cheap 2SK182's, but they vanished, stock melted down I guess :scared: I generally wait too long.

So instead of buying 6 pieces THF51 old stock to be roughly only DC-matched by me into one pair . . . I bought one of the last great really curve-matched pairs from Watanabe. Expensive, tax to be added too, 🙄, but saves a lot of headache.

imho, better than just DC-matching. :
The variation in the curve is probably also the harmonics when used in the SE-schema.
I remember when I worked in China, they had "harmonics matched triodes", the mA deviated between the two in the box but sound was similar. Very elusive box.​
 
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I've noticed several individuals mention cleaning their SITs. One of my 2SK182's could use some TLC, but I'm curious, is there any risk to just leaving them be? Is there a concern about the mica (the blue ring is mica, right?) not providing a proper seal?
 

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They provisoned a $ 10.32 refund.
I rejected this.
No response at all.
I think, they just wait now, while negotiation time is finished.
The whole situation resembles to the judgement procedure in Hungarian film, A Tanú.
The Witness (1969 Hungarian film) - Wikipedia
"Excuse me, comerad Virág, but this is the judgement."
Tanu - Elnezest Virag elvtars ez az itelet.... - YouTube

My suggestion is, they can keep this money, for that unfortunate event if Mr. Jack Ma dies, they can buy a wreath on my behalf.

We are at Partial refund 30.95 USD without returning goods .

Rejected.

They've made a comment:

"counterfeit goods Invalid
Please notice" Brand Name: KLFA" in your order."

Yes it is true, I didn't noticed yet.

But I didn't know, KLFA store manufactures original Tokin SITs?
Anyone, with some information about it, perhaps?