Ebay preamp FET

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i can't see enough to be sure , but I believe this board is a combination of Erno's jfet input and VAS stages and possibly a bipolar or jfet cascode output stage. The input needs IDSS selected and matched 2sk170BL / 2SJ74BL pairs and the VAS needs higher IDSS selected and matched 2SK170V/2SJ74V pairs - the output stage might be bipolar or jfet can't see enough to tell. If you have a source for the jfets - especially 2SJ74's let us know. I have built a large number of Erno's kits bought from Erno himself- out of respect for his intellectual property i'll leave out the IDSS values to build these knockoff boards.

I believe the kit lists some substitute jfets , but your on your own for selecting them for IDSS values or where to get them.
 
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He retired about more than 1 year ago. Audio Amatuer magazine (now Audio Xpress ) has many of Erno's articles starting from 1985 and many other years after that about his preamp and amp projects. There are many hints there, but sometimes not all the details like the IDSS values.
 
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