Did my new KEF Q150s blow my amp
So I decided to give my wife a nice present for her birthday.
She is disabled and listens to music about 4 hours a day. She has been listening to a pair of vintage Ultralinear speakers through my also vintage Sansui 5000x.
I wanted to give her something nice so I bought a pair of KEF Q150s and a SVS SB-12-nsd sub. She likes her bass.
Hooked everything up and the first day every thing went well. Playing at very moderate listening levels.
Second day the right channel with (what I will call KEF-1) stopped working. A power cycle of the amp fixed it.
Ok, simple glitch I said.
Third day have the same problem only multiple times.
Fourth day I decide to put KEF-1 on the left side and KEF-2 on the right. Is it the speaker or the amp.
I also plugged the amp in to a Kill A Watt meter. It is reading about 15 watts while we are playing music.
Well the right channel goes out again. I am thinking that maybe by some strange coincidence the right channel decided to go bad when I hooked up new speakers.
The amp supports 3 sets of speakers, A, B, and C. I hook both KEFs to C. At least we will have more than one channel sound. Nothing. OK, I don't think I have ever hooked anything to C before so maybe it has always been bad and I didn't know it.
I had previously been using the B channel with another set of speakers so I unhook the wires from those and hook up the wires from the KEFs. I have not swapped speakers back so KEF-1 is still on the left side.
So now the left side on B goes out and won't come back.
I hook the KEFs back to A. Now the right side is working and the left side is dead.
I hook the Ultralinears back up to A and the right side is working and the left side is dead.
I am thinking that the KEFs are killing my amp. They say 8 ohms, min 3.8 ohms on the back.
With a meter I measure 3.4 ohms on both.
The Sansui is rated 85w per channel with a 4 ohm load and 60w per channel in to an 8 ohm load.
I guess I will be calling KEF tomorrow. I am very disappointed. The amp has run flawlessly on and off for years until I hooked up the KEFs. I opened it up about three months ago to inspect it and put a little deoxit on the pots and it looks almost new inside. No evidence of leaking caps. A slight film of dust on the top which I blew out and on the bottom it looks like it just came off the assembly line.
Any thoughts on what might be going on?
I just ordered a new amp for her but I don't think I want to connect the KEFs to it.
Is it OK to do a double post and post this over in the speakers thread also?
Last edited by aveatch; 12-02-2019 at 08:23 PM.