During a recent store clearance, we found a tube of unmatched SJEP120R100's that was not in our inventory record !!!!
We have now measured them all at 55°C as usual, and can offer them one last time.
For the J2-Clone build, when using the circuit I published, the Power JFET bias is adjusted by varying the current source and not the 2SJ74 drain resistor.
Thus, for best channel matching, it is more important to match transconductance at bias, rather than Vgs.
We have therefore done the pairing this time according to Yfs at 1.25A.
6 pairs of the above have Yfs matched to below 4% Yfs, two of them actually to 1%.
This corresponds to 0.4dB difference in Open Loop Gain (OLG) between 2 channels.
One pair is slightly higher at 6.6%, or 0.6dB difference in OLG.
Currently, the known eBay dealer is offering them at 165USD per piece, unmatched.
And he has only 2 pieces left.
https://www.ebay.com/itm/202756261818
We shall offer all 7 pairs, each together with a pair of Vgs matched 2SK3497 as before to form a "J2" Q-Set.
i.e. each subscription is for ONE pair of matched SJEP120R100 + ONE pair of matched 2SK3497.
For the 6 pairs below 4% match, price will be 2800HKD, including postage by e-Express with added insurance.
For the 1 pair with 6.6% match, price will be 2500HKD, including postage as above.
Note that e-Express is not available to all countries, in which case it will be sent by registered air mail.
Please add your nickname and country to the subscription list.
And indicate additionally if you prefer the low-cost Q-Set (first come first serve).
Thank you for your interest,
Patrick
We have now measured them all at 55°C as usual, and can offer them one last time.
For the J2-Clone build, when using the circuit I published, the Power JFET bias is adjusted by varying the current source and not the 2SJ74 drain resistor.
Thus, for best channel matching, it is more important to match transconductance at bias, rather than Vgs.
We have therefore done the pairing this time according to Yfs at 1.25A.
6 pairs of the above have Yfs matched to below 4% Yfs, two of them actually to 1%.
This corresponds to 0.4dB difference in Open Loop Gain (OLG) between 2 channels.
One pair is slightly higher at 6.6%, or 0.6dB difference in OLG.
Currently, the known eBay dealer is offering them at 165USD per piece, unmatched.
And he has only 2 pieces left.
https://www.ebay.com/itm/202756261818
We shall offer all 7 pairs, each together with a pair of Vgs matched 2SK3497 as before to form a "J2" Q-Set.
i.e. each subscription is for ONE pair of matched SJEP120R100 + ONE pair of matched 2SK3497.
For the 6 pairs below 4% match, price will be 2800HKD, including postage by e-Express with added insurance.
For the 1 pair with 6.6% match, price will be 2500HKD, including postage as above.
Note that e-Express is not available to all countries, in which case it will be sent by registered air mail.
Please add your nickname and country to the subscription list.
And indicate additionally if you prefer the low-cost Q-Set (first come first serve).
Thank you for your interest,
Patrick
