My KLH subwoofer (model ASW8-120B) has stopped working and emits only a low-pitched hum.. I have tried hooking it up using the ''high-level'' 2-wire inputs as well as the ''low level'' RCA plug inputs. Neither works. Is there a practical way I can repair or replace the amp or related component? Obviously, I wouldn't do it if it meant paying enough to buy a new one. Thanks!

I would check the caps on the power supply. They are rather large electrolytic capacitors that will look like they burst and/or leaking. When these die, the caps ground and the sub will make a loud buzzing sound. If you are handy with a soldering iron you can replace them yourself. Replace them with the same voltage or a little bigger and same with the size.

If the cap. says 16v 4700pF on it, for example, a 20v 5300pF or a 16v 6200mF cap. will work for this application.

Yes, the 10-120 can use a L & R low level subwoofer input. You can get a short 6" RCA splitter adapter from Radio Shack for a under $10. (1 female input, 2 male outputs) Alternately, just plug the subwoofer output on your receiver to just the low level R channel on the KLH sub.

parallel wire connections

I have the same amp. there a two ways to use it: The phono plug inputs are low level, are for use as an amplifier only, and their only output is the subwoofer output. In this case, any stereo satellite speakers would be driven directly from your stereo amp.
The high level inputs are meant to be driven as the same as speakers from your stereo amp. A circuit inside samples the bass and directs it to the sub amp and output. this same circut passes unamplified outputs to the satellite outputs. PM me at [email protected] if you need further info.

Did you ever find a solution for this problem? I have the exact same thing happening with my KLH subwoofer and I'd love to know how to fix it!

Jeremy,

Read one of my posts:
I used a hairdryer and blew hot air into the grill on the bottom of the subwoofer enclosure which reduced the delay time from ~1hr to 5 minutes. (The high pitched noise was still there for about 1-2 minutes)

On the subwoofer's L&R input, you'll see a tiny "mono" next to the Left input. Hook up your receiver's single sub output to this jack and you're all set.

You need to take a closer look really, see if anything on the power supply board inside has melted, burned, popped, etc.

Yes, you use a subwoofer cable and hook it into the mono rca jack in the back of the sub. or you can use a Y splitter 1 female to 2 males. or if your amp has 2 sub outputs (L&R) then use both. I do believe it's said that if you use the high level input, it's better. I forgot why...

Oh yeah. the difference between the 2 is a high level input allows the currant from the amp to pass through the sub, thus allowing the continuation of wattage to your other speakers.
Low level input is only taking a audio signal from the amp. No power is being sen through the connection.

just try leaving it unplugged for a while thats what i did and it fixed it