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previous: Rick Doebele Hello,I just got a ... -- 5/26/2000 3:15 PM view thread

Re: Blackface Bassman filter caps

5/26/2000 5:20 PM
Ted Pimm
Re: Blackface Bassman filter caps
Rick, those values appear high compared to either the AA371 or AB165 values. If yours is a 67 it is probably one of these. Check the schematic and you'll see it calls for a pair of 'stacked' 70uf's as the main supply filter and interstage values of 20uF. The schematic calls for an 8uf as the last decoupling cap but mine was 16 or 20uF if I recall correctly.  
 
I doubt the sound you are describing is related to the filter caps. Problems with these will usually create a 60Hz HUM not a higher-frequency static sound. Could be thermal noise, poor layout (heater induced noise into grids).  
 
Be safe if you're new to this and read the FAQ.  
 
Ted.

 
Replies:
Rick Doebele Hi Ted,You are righ... -- 5/26/2000 7:09 PM