KSW 300 and humming. 60 cycle hum???

[runninshine]

I just bought a KSW 300 for a super deal (or so it might be) well, when I turn it on it sounds like 60 cycle hum. It's not very loud but when it's quiet you can really hear that thing humming.

I should be able to get rid of the humming by changing the ground loop by running a wire from a grounding point on the sub to a grounding point on my receiver.......well, it didn't solve anything.

Is the sub in need of repair or do I need to shell out more $$$ and get a audio isolation transformer?

[CECAA850]

Have you tried it in different receptacles?

Have you tested your ground loop theory with a cheater plug to make sure it's a ground loop and not an amp issue?

Are you testing it with the sub signal cable disconnected?

[runninshine]

Have you tried it in different receptacles?

Have you tested your ground loop theory with a cheater plug to make sure it's a ground loop and not an amp issue?

Are you testing it with the sub signal cable disconnected?

Yes

I have been trying to figure out if it's a ground loop issue......can you explain the cheater plug for me?

Yes

[CECAA850]

A cheater plug is just an adapter that goes between your wall receptacle and your power cord. It has 2 prongs that go in the wall (no ground) and 3 holes to plug your power cord into. They look like THIS. If the hum goes away, you know it's ground loop noise.

[runninshine]

A cheater plug is just an adapter that goes between your wall receptacle and your power cord. It has 2 prongs that go in the wall (no ground) and 3 holes to plug your power cord into. They look like THIS. If the hum goes away, you know it's ground loop noise.

I had an old 3 prong plug that would fit the sub and I cut the ground pin off that and plugged it in and the noise was still there.

I have been reading about this product and wonder if it might work, but if so, how would I be able to hook up the sub?

[CECAA850]

I had an old 3 prong plug that would fit the sub and I cut the ground pin off that and plugged it in and the noise was still there.

I wouldn't buy anything else. If you have a cheater plug on the power cord and no input RCA cable attatched and the noise is still there, then you have an amp issue.

[runninshine]

I have exhausted all ground loop issues (I think) Can I call Klipsch and get a diagram and fix this myself, or take out the guts and have them repaired somewhere?

[CECAA850]

I doubt you'll find a schematic. You might take the amp out (it has to come out anyways) and look for burn marks. You might get lucky

[Trey Cannon]

Does the sub hum with it just pluged into the wall? Nothing else connected.

IF so, then I would be looking at the filter caps on the power supply. Tech support can give you a schematic / service manual.

No cost...or send me your email and I will send it to you.

IF it does not hum then the problem is outside the sub.

Contact me and I can talk you through finding the problem.

[Klips_USA]

I have this problem with my KSW 300. With no ground connected and no input signal, I still have the hum. If anyone has successfully fix this with replacing any particular components (i.e., caps, etc.) please let me know.

Thx

[mustang guy]

when is Klipsch going to start using better amps in thier subs?

[Klips_USA]

I'm not sure when or if they are going to use better amps. I actually have a KSW300 and

SW12 subwoofers. The KSW300 has a hum and the SW12 has some form of internal intermittent. Both subs are pretty worthless at the moment

and I can’t afford a new one at the moment.

Hence, I’m hoping that I can get one of them working again. But that is two for two on the reliability side

of things. :-(

I’d have to think really hard before

considering another Klipsch sub. I

really haven’t had any issues with all of my other Klipsch speakers including my

home theatre set and about 3 sets of PC speakers. Maybe they should stick to making non-powered

speakers and leave the electronics to someone else. lol ???

They're main facility is not that far from me. Maybe they could hire me to help them find a better supplier and/or design. ROFL

[twvette]

Same problem with mine and it just gets worse over time. Could not live with it no more.

Since there are no amp replacements available through Klipsch and it seems people really struggle to find someone to fix this or for a fix to hold up over time started looking for alternatives. Just stumbled on a Yung SD300 amplifier that will drop right in the existing cutout for original amp and only $140! both the hole and the plate recessed cuts should work which is pure dumb luck (all within like an 1/8in and slightly smaller so no cutting)! You will have the other original Klipsch panel with all the adjustment knobs etc. still installed along with this new amp and integrated adjustment knobs but I dont see why that would really bother anyone especially since its in the back and should not be visible. I doubt the bolt holes will line up but this is easy to drill new ones or similar. It appears only Parts Express carries these and its a new product for them that wont be available until April which wont work for me.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=301-508

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=301-510

Option2, and what i did, was buy an external amp that will sit ony my stereo rack. Upgraded to a 1000W amp so will see if the sub hold up and its about $400. Just gain access to the wiring by removing the amp, cut sub wires, and get some binding posts to rewire the sub up to to get the sub/speaker wires outside the box (or if you are really a cheapo run them out the large air vent LOL). I am going to redo all the wiring to the sub with either 10 or 12 guage wire while I am at it especially as my sub will now have a somewha tlong speaker wire run to the external amp. I bought the binding posts where you just drill a hole in the enclosure and insert them in and secure. Can then either solder the speaker wires up to the binding posts or use some good gold .250in quick connects. Here is exactly what I bought:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-811

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=091-1245

http://www.sonicelectronix.com/item_41120_Xscorpion-FS10B.html?SearchClickout%5Bquery_id%5D=5737251&SearchClickout%5BIgnore%5D=1

I am just glad to have found some options to keep this great sub functional and I now know how to keep it going for decades to come even if I next have to replace the sub. Well worth it rather than trashing it.