I would be interested to build Borbelys all-JFET balanced line amp according to attached fig17 from his article.
It would be convenient to use easily available parts. Have found that Digikey would have the dual JFET LSK389 in stock and also TIs JFE2140 might be an alternative for a fair price. Toshibas single 2SK209 appear to be available as well.
Making it with SMD parts could allow for a real estate-efficient design according to the attached picture and a compact line amp might be usable as a front end for a buffer amplifier as well as a preamp.
Have endeavored to calculate on bias currents and contemplated over suitable components for cascoding transistors and for the current limiting diode J511 but quickly realized that I need more studies prior being able to confidently produce any fruitful results.
I wonder if anybody have tried this design with newer parts and if I would be able to take advantage of somebody else's labour?
Grateful for any advise or info that anyone would be willing to share.
Chris
It would be convenient to use easily available parts. Have found that Digikey would have the dual JFET LSK389 in stock and also TIs JFE2140 might be an alternative for a fair price. Toshibas single 2SK209 appear to be available as well.
Making it with SMD parts could allow for a real estate-efficient design according to the attached picture and a compact line amp might be usable as a front end for a buffer amplifier as well as a preamp.
Have endeavored to calculate on bias currents and contemplated over suitable components for cascoding transistors and for the current limiting diode J511 but quickly realized that I need more studies prior being able to confidently produce any fruitful results.
I wonder if anybody have tried this design with newer parts and if I would be able to take advantage of somebody else's labour?
Grateful for any advise or info that anyone would be willing to share.
Chris
