[Boatanchors] Johnson 500 audio problems

Gary Franklin franklin6209 at att.net
Mon Oct 3 15:00:04 EDT 2016

Trying to diagnose the weak distored audio problem I have with the 500, 
I see where the clipper stage (6AL5) was removed and replaced with an 
additional audio amplifier stage using a 6C4. I also see a small perf 
board installed using a  circuit made up of a resistor, three diodes and 
a SK3021 NPN  high power transistor. Wondering if this is some kind of 
solid state clipper??   Anyone familar with these mods?  I believe the 
extra audio stage mod is a WA1HLR design. In his article he recommends 
removing the clipper stage and replacing it with another audio stage 
using a 6C4 or 6AT6. He does not suggest a clipper stage.



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