MOTU 828 Mk ii buzzes like a bumble bee.

[Kolakube]

Hi all,

Just got an 828 mk ii second hand of Ebay.

When plugged into the mains with no other connections (so not a ground loop or anything audio) it buzzes. Its about as loud as a blue bottle fly trying to get out of the window. So not defining but defiantly annoying considering no fans inside or working parts.

Is this normal? Anyone else got one they can check out?

[2M]

I got one, and it is absolutely dead silent. Perhaps the power supply is faulty?

[Kolakube]

Hi, thanks mate.

Ill contact the seller and see whats what re a return. He seems a decent guy.

Hopefully he'll be just as decent at aftersales.

[Hugh Robjohns]

If you're talking about an acoustic buzz, it's probably the mains transformer laminations rattling, which is anoyingly common.

hugh

[Magic Matt]

My HiFi amp started doing that after I moved - I figured maybe it had been knocked or bumped and we'd just not been careful enough... it was like it for about 2 months and when I was eventually looking at replacing it, it just suddenly stopped buzzing and has never done it since.

Just saying it's possible it may have been fine before being posted and it's a result of something happening during transport/shipping...

Is it possible this kind of thing could be a loose screw or a dead easy fix?

[Kolakube]

Thanks guys, yes he's took the return so all good.

[ef37a]

You know I would have put money on MOTU using a SMPSU?

But no, a (very!) careful perusal of the manual shows they are supplied in 100-120 or 230V format indicating a 50/60Hz supply.

Rattly mains traffs really should not happen these days, especially in such low power, high'ish end gear. If the "re owner" is looking in I would task MOTU to repair the unit free of charge and then bounce the transformer back to their suppliers for a report.

There ARE some advantages to line lumps!

Dave.