humming on CA 540 A V2

[admin_exported]

Hi, i'm a brand new forumer from France. I recently purchase a CA 540A V2 and I have to admit that I very happy it really sounds sweat and fine but I notice recently a little hum or buzz coming from the box itself where the amp is on stand by. I can notice this noise 3 feet away in a silent room. This hum/buzz is not comming from the loudspeakers and is not affected when I put the volume up. In fact I can't hear this hum/buzz while music is playing. I revert to CA and they explained me that toroidal transformer are subject to electric noise but that in no case this should affect the listening experience. I would like to know if it's fine and normal or if I have to return it to my distributor. Thanks in advance and sorry for my english.

 

[Anonymous]

Don't know about the 540A, sorry, but my 640A never made that type of noise.

 

[matthewpiano]

Some mechanical hum is normal from most amps - I've come across it on Cambridge, NAD, Naim, and Pioneer models amongst others. It can be exacerbated by placement on particular surfaces and by nearby mains interference from other components or other electric items. For example, do you have your CD players on on top of, or very close to, the amp? Is there a heater or fridge on the same mains ring? If the latter you can buy mains silencers to reduce this interference.

 

[Anonymous]

thank you for your reply. In fact I try to connect the amp alone directly to the in-wall main and this little disturbing noise is still here. Again I have to admit that this humming does not affect the listening. I just want to know if it's a defect that can get worse in the future or if I have to live with that. I bought a main filter and a new main cable (clearest audio) but it does not change anything. I have a NAD C320 bee which is perfectly silent.

 

[Anonymous]

Fimbo, it sounds like transformer hum. In most cases its nothing to worry about. Transformers will vibrate at mains frequency, 50/60 Hz and sometimes this becomes loud enough to be audible. Matthewpiano made some good points about how the equipment is placed because the transformer vibrations will cause the case to resonate and the metalwork of the case will amplify the sound. Try seeing if the hum reduces by putting a fairly heavy weight on the amp but use something solid not another hifi component.

EDIT....forgot to say....I have a 540 and it is very quiet. Luck of the draw I suppose. I suppose its up to you to either keep or return

 

[rymidd]

my roksan has the a slight hum where my nad is quiet as a mouse i guess some tranformers are bigger than others and bigger one will make more noise

 

[Anonymous]

thank you guys for your ideas... I tried something and I was very surprised: my amp is on the top of my cd player (a 540 C V2). I tried other positions (the cd player on the top of the amp, or side by side) but the humming does not stop. the only moment when I can hear that the noise is clearly decreasing is when I hold the amp in my hands away from any surface... I assume (and thanks to your advices) that it's a problem of vibrations... Any idea to solve it?? and if not do you think that it can affect the amp??

Thanks again...

;-)

 

[ellison]

If its the transformer humming theres not a lot you can do.Ferrite rings
on the mains lead or mains filters probably wont stop it.Its possible that the transformer bolt can be tightened which might help a bit, but i wouldnt recommend doing this yourself as youll obviously void your warranty.I have a musical fidelity a5.5 and the hum from that is diabolical .i personally think that some manufacturers use cheap transformers because of cost or profit. If its bothering you ,i would personally take it back to your dealer and ask for a replacement,rather than spend money on things that wont cure it.

ellison

 

[Anonymous]

fimbo:
the only moment when I can hear that the noise is clearly decreasing is when I hold the amp in my hands away from any surface... I assume (and thanks to your advices) that it's a problem of vibrations... Any idea to solve it??

If it is the amp's vibrations being 'amplified' by the surface it is sitting on:

Find somewhere that sells granite chopping boards (if you live in the UK Tesco often sell them) - cost approx £10-12. Now pop to the sports shop and buy two squash balls ~£3 each.

Cut squash balls in half and place on on the table spaced to fit each corner of the granite. Place the granite on top of the rubber feet. Hey presto you just saved £100 on an isolation platform. I even use one to stop the vibrations from my PC being transfered to the floors. Works wonders. Also reduces vibrations from other things in the house effecting the hifi.

Oh and personally I'd try taking it back for another first!