The Redmere Soloist
Channel 2 Schematics and Layouts
The BF244B FET is obsolete and it's getting harder to find current production through-hole devices. Even the BF256B mentioned as a replacement in one of the drawings below has now gone out of production. Since this application is in the signal path rather than used as a switch, it might be best to try and source an original part.
One new device that might do the job is the J211 D74Z from ON Semicoductor/Fairchild if you swap the Source and Gate pins around. Mouser part number is 512-J211_D74Z.
Pin-out mismatch between old and new components is a bit of a problem right through the amp, as a lot of 1970s semi's seemed to favour a (now uncommon) layout used by Japanese manufacturers at the time.
Channel 2 Schematic. S-3-1 Boards
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Channel 2 PCB Layout. S-3-1 Boards
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Channel 2 Schematic. S-3-2 Boards
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Channel 2 PCB Layout. S-3-2 Boards
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