Up for sale is a pairs of low noise, high Yfs 2SK240/2SJ75 JFET transistors. Transistors are New Old Stock and are absolutely genuine. 2SK240/2SJ75 are well known among the audio society but unfortunately are out of production and that's why are very rare nowadays. 2SK240 datasheet, 2SJ75 datasheet.
2SK240 and 2SJ75 are dual JFETs as you can see from the picture
and each of them is formed by two manufacture matched discrete JFETs tied together with aluminium cap. As a matter of fact 2SK240 is a pair of two 2SK170 and 2SJ75 is a pair of two 2SJ74. That's why purchasing a pair of 2SK240/2SJ75 you'll get a quad of 2SK170/2SJ74 which makes them the best choice for various audio circuits based on Erno Borbely's designs.
Here you can see 2SK240/2SJ75 in action:
All transistors have Idss in range 7 - 10 mA and Ugsoff between 0.4 - 0.5 V. The matching between 2SK240 and 2SJ75 devices is done with Locky_z Intelligent Curve Tracer ( Locky_z Curve Tracer). Below are some sample pictures from real measured devices using Locky_z Tracer.
As you can see, the matching between devices is very close.
I declare Idss matching between K240/J75 at range of 2% but usually it is well better.
Note: Due to the long warehouse storage some scratchings of the transistor's bodies are possible.
What the buyer will receive:
1 matched pair (2 pcs.) of 2SK240BL/2SJ75BL dual low noise high Yfs JFETs (matched quad 2SK170BL/2SJ74BL).
The items will be shipped with Registered AirMail, so a tracking number will be sent immediately upon shipment.
The price I'm asking for a 2SK240BL/2SJ75BL matched pair is EUR 30 (PayPal fees included).
The shipping cost for Worldwide AirMail Registered is EUR 3.
I have a limited quantity of matched pairs that's why if you have an interest send me a PM with query about availability.
An externally hosted image should be here but it was not working when we last tested it.
2SK240 and 2SJ75 are dual JFETs as you can see from the picture
An externally hosted image should be here but it was not working when we last tested it.
and each of them is formed by two manufacture matched discrete JFETs tied together with aluminium cap. As a matter of fact 2SK240 is a pair of two 2SK170 and 2SJ75 is a pair of two 2SJ74. That's why purchasing a pair of 2SK240/2SJ75 you'll get a quad of 2SK170/2SJ74 which makes them the best choice for various audio circuits based on Erno Borbely's designs.
Here you can see 2SK240/2SJ75 in action:
An externally hosted image should be here but it was not working when we last tested it.
All transistors have Idss in range 7 - 10 mA and Ugsoff between 0.4 - 0.5 V. The matching between 2SK240 and 2SJ75 devices is done with Locky_z Intelligent Curve Tracer ( Locky_z Curve Tracer). Below are some sample pictures from real measured devices using Locky_z Tracer.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
As you can see, the matching between devices is very close.
I declare Idss matching between K240/J75 at range of 2% but usually it is well better.
Note: Due to the long warehouse storage some scratchings of the transistor's bodies are possible.
What the buyer will receive:
1 matched pair (2 pcs.) of 2SK240BL/2SJ75BL dual low noise high Yfs JFETs (matched quad 2SK170BL/2SJ74BL).
The items will be shipped with Registered AirMail, so a tracking number will be sent immediately upon shipment.
The price I'm asking for a 2SK240BL/2SJ75BL matched pair is EUR 30 (PayPal fees included).
The shipping cost for Worldwide AirMail Registered is EUR 3.
I have a limited quantity of matched pairs that's why if you have an interest send me a PM with query about availability.
Yes, it is possible. You have to cut the metal cap with sharp pliers. As a matter of fact, I already did that operation with one cup because of curiosity and due to the fact that transistors inside it was not closely matched.
I can upload pictures if you are interested.
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No I didn't see any dots on the caps. About the Drain's position - the pins' placement is the same as in the K170/J74
Here are the promised pictures of opened device:
Well, it wasn't a gently cut
, but transistors were safely detached from the body.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Well, it wasn't a gently cut
, but transistors were safely detached from the body.
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