Speaker humming from a new Mcintosh MA252

[Berman002]

Hi all, i just found that my ma252 having a humming sound from the speakers, not sure since day 1 or not.
humming sound when you put ur ear right next to the speakers.
both speaker and volume does not affect it.
can any of the expert help please?
I have tested all sort of things that i can test so far, nothing work.
tested:
no input.
different power cable,
different speakers,
different power point,
turn off all the power in the main except the audio power point.
test with 2 pin power plug

the humming still there as long as the speaker is connected and the amp is turned on. it's not affecting my listening, but still ignoring.....
may need to take back to Mc to service.......owned it for 3 months only from new....... any suggestion guys?

[bigblue]

What happens if you disconnect all other equipment from the 252?
Are they all connected to the same group of outlets or do you have a power strip/power conditioner?

[Berman002]

Originally Posted by bigblue

What happens if you disconnect all other equipment from the 252?
Are they all connected to the same group of outlets or do you have a power strip/power conditioner?

Hi there,
Yes i did remove all input, only power and speaker connected to the Amp MA252, speaker still hum, both channels and increase the vol doesn't make it louder.
all connected to the same power point.
i also tested plug in a headphone and play music to the headphone, the speaker connected to it still hum.
><
i also asking mcintoch, but no answer from them yet.
i can only hear the hum if i put my ear right in front of the speaker closely.

[ps7256]

Originally Posted by Berman002

Hi there,

Yes i did remove all input, only power and speaker connected to the Amp MA252, speaker still hum, both channels and increase the vol doesn't make it louder.

all connected to the same power point.

i also tested plug in a headphone and play music to the headphone, the speaker connected to it still hum.

><

i also asking mcintoch, but no answer from them yet.

i can only hear the hum if i put my ear right in front of the speaker closely.

Are your interconnects and power chords running parallel? If not try running them over each other but elevated.

[tdelahanty]

If you can't hear it from your listening position, may be considered normal, remember this amp has a tube front end.

[Formerly YB-2]

You must be new to tubes. In gear with tubes you always roll in new tubes first to see if one of yours is noisy. You only need to purchase 1 or 2 new ones (our own vintage_tubes is a great source for reasonably priced & fully tested tubes - tell him your problem when you purchase). Replace one tube (or one per channel) to see if the one you took out might be the offender. If not, swap the tube in the next position. Tubes have AC on their filaments and can be noisy.

[Berman002]

Originally Posted by Formerly YB-2

You must be new to tubes. In gear with tubes you always roll in new tubes first to see if one of yours is noisy. You only need to purchase 1 or 2 new ones (our own vintage_tubes is a great source for reasonably priced & fully tested tubes - tell him your problem when you purchase). Replace one tube (or one per channel) to see if the one you took out might be the offender. If not, swap the tube in the next position. Tubes have AC on their filaments and can be noisy.

Yes i am new to tube, this is my first tube amp. but this ma252 amp and it's tube, both 3 months old only. noisy from both channel too.
anyway, i am going to buy 4 new tubes to test it.
I also got feedback from other ma252 owner, few of them having the same noisy when they put their ear in front of the speaker.
Thanks

Thanks

[62caddy]

What are the speakers you're using?

[Berman002]

Originally Posted by 62caddy

What are the speakers you're using?

KEF LS50 and Focal 906

[Ampteks]

I purchased a 252 and had the hum since day one, took it back a week later for a refund.