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Issue with Krell KSA-250

Hello-

It's been a minute since I've been on the forums here, but I'm glad they are still around!

I am the second owner of a Krell KSA-250 amplifier. For the past 10 years it hasn't given me any problems. Then today, when I turned it on, it emitted a rather loud buzzing sound. This wasn't coming from the speakers (like a ground loop hum), this was a very startling almost "mechanical" buzz sound. The buzz does not stop until I turn the unit off.

I'm not sure where to start. I called my local audio repair store, but they don't work on Krell. They suggested I contact Krell, which is my next step, but seeing as I'd have to freight this for it to be repaired, I'm hoping someone here might shed some light on what's happening. I've made a short 15-second video of the issue, but I don't think I can upload it here. I'm happy to provide it though.

Any thoughts you might have would be appreciated.

Thanks,

Blake

blakeh
jea48
4,425 posts
 

@blakeh

I listened to the video several times. Hindsight is 20/20. Shame you didn’t leave the top cover off for the video demonstration. I would have placed one hand, with finger cupped like holding a softball, and lightly touched the top of the round can covering the power transformer. (I believe a Toroidal transformer.) If the sound is coming from the transformer you would feel the vibrations of the sound.

Example of a 60HZ hum/buzz sound from a power transformer.

60HZ

60Hz

That’s not the frequency sound in your video, imo.

 

.

invalid
1,186 posts
 

@jasonbourne71  I know capacitors don't buzz, but they can cause the transformer to buzz.

invalid
1,186 posts
 

Is the amplifier a ksa 250 or 250s?

blakeh OP
5 posts
 

@jayctoy Do you know of any other reputable shops in the city/'burbs? I know Stereo Rehab is well regarded, but their turn-around times can sometimes run into the 3+ month range. I'd like to get my amp back a little quicker than that. Midwest Audio is closed as far as I know. Not sure where else to call. Any leads would be appreciated.

@invalid This is a KSA-250.

jdsmichaels
7 posts
 

I am an original owner of a Krell KSA 250 , when my KSA-250 had a buzzing sound I drove from Massachusetts to Ct service department . They had to replace all the caps large and small . They actually said they never seen a KSA-250 with that many caps that needed replacement ! Being an original owner, willing to bring in the amp myself ,  and having an unusual number of capacitors gone bad , they gave me a break on the repair bill . Great service department , friendly service manager . 

Best of luck with your repair

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