Help Identifying Cap.....

[SA-12]

if it is so then it is a varistor, 40 or 60 v. Why would you want to change this?

[SA-12]

I remember when I first got into this I was changing all the perfectly good caps in amps I would pick up at yardsales and such. Years of reading books, and wasting money showed me quickly that ceramic disc caps are very rare bad, no point in messin with them. Focus on old electrolitic and film caps. Also mica caps tend to live a long life so save your pennies. Tantalum caps are worth checking. The best equipment I have used to date to check caps is a esr meter that I bought as a kit and built, you can get it here http://www.mainelectronics.com/esrkit.htm

This combined with a capacitance meter will save you big bucks, never mind changing every cap anymore most are still ok anyway.

[unclejed613]

that device is a "poly-switch" self resetting fuse. they frequently go bad in crossovers. they're used to protect the tweeter, and what frequently happens is once they activate, they cut the power going to the tweeter by about half. so somebody turns the highs up more to compensate, and sssssssstt! the poly switch burns open. it's better to use a lamp in series with the tweeter as the lamp will actually limit the current. poly switches just switch to a high resistance state and stay there until they cool down.

[SA-12]

I always wondered why my bose 601 series 1 speakers had small lightbulbs inside .