2. amps-preamps
  3. 191496-195982

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
oddiofyl's avatar
oddiofyl
3,734 posts
 

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

oddiofyl's avatar
oddiofyl
3,734 posts
 

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

russ69's avatar
russ69
3,467 posts
 

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.

randywong OP
8 posts
 

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!

oddiofyl's avatar
oddiofyl
3,734 posts
 

Excellent 

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