My krell kas mono-block power suppy has a noticible hum when it is on stanby. I've read somewhere that it is the power supply filter caps that has gone bad. Is the filter caps the main big caps in the power supply and is it fairly easy to change? I don't want to send the amp back to krell cause it would costs a lot and it would be more fun to do it myself. Does anyone have a simillar experience they can share with me or can help me with this problem?
Thanks Minh
Thanks Minh
Hi
My experience has been that at peak power periods- especially round about suppertime my Krell amp transformers tend to hum. Also when somebody close to me is doing some welding in his backyard. The best is possibly to switch off during these periods.
Jozua
My experience has been that at peak power periods- especially round about suppertime my Krell amp transformers tend to hum. Also when somebody close to me is doing some welding in his backyard. The best is possibly to switch off during these periods.
Jozua
Hi CBS240,
Yes indeed that's exactly what it sounds like! 😀 😀
But hey, they're getting something special ... I'm sure they know what they're doing?
Cheers,
Greg
Yes indeed that's exactly what it sounds like! 😀 😀
But hey, they're getting something special ... I'm sure they know what they're doing?
Cheers,
Greg
Sorry Minh,
A couple of armchaire critics I guess, playing old favourites! Maybe a good power filter is in order.
Or ask (pester) Krell about it!
Cheers,
Greg
A couple of armchaire critics I guess, playing old favourites! Maybe a good power filter is in order.
Or ask (pester) Krell about it!
Cheers,
Greg
All transformers hum more or less, by nature but some may hum more. Toroid transformers may also be very sensitive againt DC on the mains and "DC" is simply unsymmetrical waveform coming from hairdryers, microwave ovens and other "non-resistive" loads.
Hi
I would love to have those Krells- I used to drool over that model in the magazines.
I have the KSA100 and KSA200s. So far I like the KSA100 best.
Personally I would suggest that you send those specialized amps to Krell or their agents for an overall service- also they are quite "old" by modern standards and possibly in need of service. The design of those models are also quite complex and I would not suggest that a novice fiddle inside them.
My gut feeling is that it possibly is a dry soldering joint in the power supply. Years ago my KSA 100 transformer sounded as if there was loose wire inside- all it took was a resolder of the mains wire on the inside of the connecting IEE connector plug.
Regards
Jozua
I would love to have those Krells- I used to drool over that model in the magazines.
I have the KSA100 and KSA200s. So far I like the KSA100 best.
Personally I would suggest that you send those specialized amps to Krell or their agents for an overall service- also they are quite "old" by modern standards and possibly in need of service. The design of those models are also quite complex and I would not suggest that a novice fiddle inside them.
My gut feeling is that it possibly is a dry soldering joint in the power supply. Years ago my KSA 100 transformer sounded as if there was loose wire inside- all it took was a resolder of the mains wire on the inside of the connecting IEE connector plug.
Regards
Jozua
I'm a total newb but I am wondering if you have taken a voltage reading across the filter caps. (Yes, the big main caps in the power supply.)
That is the first place I would try. Measure the DC voltage across the terminals of each cap. Then measure for AC across them. If any of them read differently than the others or if you see much AC at all, the caps are probably bad. I have fixed a few power amps by simply changing out bad filter caps. They certainly can cause hum in the transformer in my experience.
Post the voltages you read and then maybe someone who actually likes Krells might be able to help you further.
Blessings, Terry
That is the first place I would try. Measure the DC voltage across the terminals of each cap. Then measure for AC across them. If any of them read differently than the others or if you see much AC at all, the caps are probably bad. I have fixed a few power amps by simply changing out bad filter caps. They certainly can cause hum in the transformer in my experience.
Post the voltages you read and then maybe someone who actually likes Krells might be able to help you further.
Blessings, Terry
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