Speakers low pitch humming, is it normal, or real issue with preamp?


I shall appreciate your experienced inputs. I just purchased pre-owned audio set, all used for 2 years and in good conditions. McIntosh Preamp C53, Amp MA462, B&W 805 d5. I noticed whenever the preamp was turned on, there is a very low humming noise coming out from speakers, can hear it only when get my ear very close to the speakers ( so probably it does not affect my normal music listening which mostly covers the noise). When I tried turned off preamp, and keep the power amp on, there is absolutely no noise, so the noise definitely comes from the C53. When I connect to the DA2 using digital input with coax cable, the noise is more pronounced (even without streaming source). I am a newbie for audio, am I too nervous, or this is normal since no component is perfect?

randywong

Make sure all your gears plugged into one circuit. Get a filter for your tv cable cord, try disconnecting Cable to see if that does anything.

 

Don’t sit so close to the speaker. Buy a puppy. Make a chocolate milkshake.

I definitely think you're too nervous and should try pharmaceuticals

Hoorays!! It’s all your inputs and inspirations! Some valuable lesson learnt: I started to set up the components all over again (without much hope), unplugged everything, and plug in the cables (and compare different cables and inputs) one by one, finally I find the problem: my most trusted Audioquest balanced cable from preamp to amp was the cause of humming! I changed it with the much cheaper wbc and problem was solved! It’s always something minor that screws up the whole plan! I am a happy music audience now!

I can hear the hissing and humming noise when I keep my ears close to speakers, so is it normal that any preamp will produce this kind of noise (even without any input cable)? Or is it an issue with my item? Sorry I am a perfectionist.

Completely normal. Has to do with the minimum gain on the preamp, your amp sensitivity, and your speakers. I would not change anything but you can put a pad on your preamp cables and that will knock it down. I also keep a pair of attenuators around just for this problem.

Its unlikely a bad component,  its noise and you just have to pinpoint it

Unplug video sources going into the C53.  Unplug their AC connections and start there.   If you are using the eArc on the DA2 start there it may a ground loop between the TV

I can hear the hissing and humming noise when I keep my ears close to speakers, so is it normal that any preamp will produce this kind of noise (even without any input cable)? Or is it an issue with my item? Sorry I am a perfectionist.

If you can only hear it from a few inches away I wouldn’t worry about it. The only setup I ever had that was Completely silent was a Lyngdorf integrated. If you sit in the quiet room and really listen and can hear something then that’s a different story. 

I agree with @soix could be a ground loop.  I would try his solution and see if that eliminates the issue.  If it does, try plugging the pre into an outlet on a different house circuit.  

Could be a ground loop.  You could try using a cheater plug to lift the ground on the preamp, amp, etc. and see if that eliminates the hum.  Not a long-term solution but at least you’ll see if that’s the problem and then go from there.  I suppose you could also try adjusting the positions of your power cables if certain ones are crossed — not likely the source of the problem but it’s free and good to rule out.  Just a couple thoughts FWIW, and best of luck in tracking down the problem.