wayne makowicki

The KSP-300 and KSP-400 seem to have this issue, nice speakers when working. I was able to get mine going not sure how long the will last. Let me know how you make out, I would love another pair, maybe put on an after market amp?

I don't have a schematic for the ksp-400, however the amps failed in my ksp-300. The fix was replacing the decoupling caps. These amps are know for failing, others have had them fixed and they fail again. Where are you located?

Both amps are working fine, both needed new decoupling caps on the low side. I used caps that have a higher voltage rating so hopefully they won't leak/blow. I haven't put the speakers to much high poer test yet but I will soon. When I get some time I will put a picture up of what was failing on both amps. BOth amps have a very poor grounding issue, they both had the area where the switch is located sanded/ground a bit to make contact. Aluminum will not work so good this way I put in a dedicated ground wire on both amps. Its possible a poor or failing ground could cause a voltage rise on the low amp side.

I got one of the amps to work I put in new caps on both the amp and "pre amp" don't think Pre amp fits perfect but its about as close as it gets. The caps on the main amp were starting to look like the end was near and one of the caps on the "pre amp" was just plain done. (all 4 caps are power supply caps) the hum is a 60 hz ripple. The second amp I will do the same however it looks like it might have other issues, at first glance none of the caps look blown but they are along in life. I will post to let you know how I do, the one I did fix sounds very good so the drive to get the other going is raized. I bought these plus a klipsch sub woofer and center for $200.00 so I know nothing of history. One thing I did notice is poor grounding of the board perhaps this leads to the failure. I did put in large caps in both places the higher voltage rating should help with the life. I will write more soon just pressed for time now. Wayne 203 417 2327 if anyone has questions call.

I can understand that, the fix cost is high. Did you like the speakers when they worked? I don't want to spend money on something that is junk.

So did you get them repaired? I am considering putting in a low pass filter and bi-amping not sure how that would work out. I also see $125.00 sub amps that might fit the box. I have two of these and both do the same thing. From what I am reading this was a common problem, it could be a simple fix on the amps. I have pulled one and will take a look at it. I work with some EE so maybe they might be able to find the problem the amp itself is not that big.

So who would service these and is it a common problem? both speakers will hum with not speaker wires hooked up if they are pluged in. I have read others have had the same issue. Can the amp be fixed or should I just find some sort of replacement? any help would be great

Yes I am using the speaker wires for a feed not the Line Level. It hums as soon as the sub is plugged to the wall and in the on position. If its plugged in and in the auto position the hum starts as soon as music is appied then stay humming.

I just bought 2 Klipsch KSP-300 for $150.00 both have a hum that comes from the sub amp, I tried without a ground same thing any fix for this? Thanks they look like good speakers I want them up and running soon.