Showing posts with label hi fi. Show all posts
Showing posts with label hi fi. Show all posts

Friday, December 17, 2010

Bell 2122 Classic 6V6 Tube Amp

Bell 2122 Working Again!


When I was in 4th grade I listened to this amp playing classical hi-fi from a FM Tuner in Chatham NJ.  Years later I took it to college with me as a freshman.  The next year I upgraded to real stereo. The Bell worked until a few years ago when the power supply had the dreaded 'Hummmmm....' of a bad filter capacitor.  A quick Internet search led me to a post by someone else who had one and I acquired a nice copy of a 1948 Sams Photofax for the unit.  This year an internet search led me to Ampmonster, an Austin TX guitar amp company that had a good write up on restoration of the Bell.  With this site and the photofax I made a list of parts needed to redo the amp but when I opened it  up yesterday I tested the caps and found many of them to test close to value the electrolytics were bad though.  I took a 220uf and clip leaded it in parallel with the HV filter and the hum went away and the 2watt resistor connecting the two filter sections opened with some sparks and a small amount of escaping smoke.  An old replacement resistor was found and seemed to run cool so I wired the cap in for a more permanent temporary fix which will allow me to play with the amp a bit if desired.  Some DeOXit sprayed into the controls seemed to help and the tubes were tested and one bad 6SC7 (dual triode similar to the 12AX7 in a metal octal package) tube was replaced.

New Filter Cap in place

Sticker inside bottom plate

Rear panel

Pair of 6V6's