BA1 FE as Line Stage or Diy FE2022

BA1 FE as Line Stage or Diy FE2022
 

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I guess it would come down to if you prefer the sound of a bootstrapped VAS w/ a MOSFET..... or a BJT VAS w/ CCS. I guess you build both and do a shootout, no holds barred, winner take all.... When I built the BA1 as a stand alone FE, I added a banana jack on the back of the chassis to allow a connection back from the output stage, to feed the bootstrap cap. Bootstrapping is a technique using AC that will greatly increase the effective resistance of R209, forcing the voltage across it to be essentially constant. Linearity is greatly improved. The schematic in post #1 is not implementing the bootstrap cap though... I would add it if high performance is desired.
 

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As a linestage? I suspect FE2022 will be the better answer, it uses much easier to obtain parts, works beautifully at lower gain, and is available now.

This post has some good notes regarding hookup and gain.

I would suggest you do not use the stock gain settings of 10x (20db) as gains that high are intended to run follower amplifiers directly. For a linestage, start with R3, R4 in the range of 20k-30k, and adjust if you still have too much gain.

https://www.diyaudio.com/community/threads/diy-front-end-2022.394339/post-7283612