[Amps] Old amps are fun! (SB-221 smoke)

[Jim Kearman]

> 
> After removing the outer cover, I see where the 1mH choke on pin 4 of 
> the inside tube (socket N) smoked.
> 
> #1  Where can I get a replacement?
> #2  What caused the failure (or where do I start looking)?

If the 221 is similar to the 220 there is no dc voltage applied to the grids, so I would look for an internally shorted tube. The tubes are dc-isolated from each other, so the tube in that socket is the culprit. 

I'd look at hamfests for a replacement but you can probably get one via Mouser et al.

73,

Jim, KR1S
http://kr1s.kearman.com/