Audiolab 8000m slight hum

[Gbeer7]

Hi guys,

As you konw i recently got my two 8000m's to partner my 8000s. The 3 amps seem to have a slight hum when you stand next to them with the sound off. I e-mailed the Hi fi shop and he repied with "It is very common for amplifiers to make some kind of hum, this is completely normal, if it turns to be a nuisance, the only way to cure itis to look into getting more efficient mains products, i.e high quality mains cables and conditioners."

Is this true ? Just a bit worried. If its normal then its not that bad to live with. Thought they might be silent. The sound is brilliant and really impressed other than that.

Graham

[Ali Tait]

Yes,quite common to hear a slight hum.It's the transformers inside.May just be slightly loose.You could try taking the lid off and checking.

[The Grand Wazoo]

Is this the same guy who thought you needed two pairs of interconnects for wiring up monoblocks?

What he says is either sometimes true or partly true.

[Stratmangler]

Is the hum audible from the listening position ?
I wouldn't worry if the answer is no.

Is this dealer the one who managed to confuse you about bi-amping ?
It's just that

if it turns to be a nuisance, the only way to cure itis to look into getting more efficient mains products, i.e high quality mains cables and conditioners.
sounds like trying to soften you up for a wallet raping session.

Cynical ?
Moi ?

[Ali Tait]

If you are,then I am too!

[The Grand Wazoo]

Yeah, well it's kind of what I was trying to imply.

[Gbeer7]

ok, ok i'm learning !!! :lol:

I have to stand next to them while its quiet to hear it. From an audio point of view, i can't hear it at all.

Cheers guys.

[hifi_dave]

They will make a noise because of the transformers inside but it's a matter of how loud is the hum. If you need to be close to them, I would suggest this is normal. If you can hear it from 4-5 feet away, thst is probably too loud.

I would suggest that expensive mains leads and the like will not make a difference to the hum. They will, however, put a few Pounds extra in the salesman's pocket....:eyebrows:

[Peter Galbavy]

I bought a pair of Chinese made 8000Ms a couple of years ago with my Denon 4308 and they hum. I tightened the transformers up and this helps a little but still noticeable from up to 3 or 4 feet away. A guy on another forum also suggested checking for internal wiring that is cable-tied up but in contact with the transformer or close components - nope. I phoned IAG and they suggested about £80 per amp to replce the transformers but I have read about this effect so much I suspect they would come back with the same hum.

When you are sitting further than 4 feet and usually with the amps buried on a stand there is no audiable effect. Mine are in boxes in the loft along with the DefTech BP10s that they usual drive - but I am keeping them all as they are rather nice :)

[Ali Tait]

Most likely cheapo transformers then.They could be replaced with something a little better quite easily.

[DSJR]

You think 8000M transformers hum. You want to try the three Crowns I have singing and snarling along together, which they all did on UK mains :(

[Gbeer7]

So how did you overcome it DSJR ?

So basically this hum is normal then ?

[DrMartin]

I think I mentioned this in your earlier thread but the brand new Audiolab 8000Ms I had for 3 days a few months back hummed like this. It wasn't noticable from my listening position but quite loud up close. I didn't like it. No other amp I've ever owned before or since hummed like this. As I said earlier, one of mine actually died completely after 3 days so I sent the whole lot back and swapped for Quad. Perhaps the humming isn't a problem but what with that and the amp failure I just lost faith completely.

[Gbeer7]

Thats a real shame Dr M, because the sound they produce is brilliant and clean. I think they also look great too. But I do love my audiolab gear. The hum on the M's is only close up, so think i can live with that.

[RochaCullen]

Hi Graham,

I've been looking at the possibility of buying some 8000m amps too. As regards your humming issue, I have read that placing amps like yours too close together may cause humming. Have you tried separating the amps so that they cannot interfere with eachother to see if that helps.

Regards,

Nathan

[roob]

Could this be a ground loop issue?

[Peter Galbavy]

Mine have been colocated and/or apart. An individual amp will hum on it's own with no cables apart from power connected. The IEC connector on the chassis has no ground pin and the unit is double insulated.

Opening the case and the hum come very clearly from the toroidal transformer. Tightening the nut doesn't make a difference. Removing the whole thing and checking the plastic/rubber isolation sheet etc. makes no difference.

It's poor transformers I think, in my uneducated way.

[hifinutt]

Could this be a ground loop issue?


yes i was just thinking this
interesting article here

http://www.audioholics.com/tweaks/connecting-your-system/ground-loops-eliminating-system-hum-and-buzz

[Gbeer7]

The hum comes from the Amp's, not through the speakers as the article states if its a ground loop problem. Think is down to the Transformer, probably !