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How quiet is your Rogue Sphinx?

I have a new Rogue sphinx, I don't recall the unit I demoed to be especially noisy but I do find my unit to have some noise despite other owners describing the model as 'dead quiet'.

In both 'standby' and 'on' there is a quiet though audible hum coming from the right hand half of the unit (maybe I can hear it through the vent on the top). You need to put your ears pretty close to the unit though.

There is also a similar hum to be heard through the mid/bass unit, audible about 2 feet away. This is aside from the more common 'hiss' that is also present. Oddly if I turn my balance control left all the way, the hum becomes much louder through the right speaker only and can be heard about 10 feet away. If I turn the balance to the right the original hum in the left speaker actually decreases in volume!

I am used to speakers having a hiss but the question I ask is do any other sphinx owners notice this extra layer of hum/buzz that varies with the balance control in this way? Is your actual amplifier unit dead quiet or does it have a faint hum also?

Just trying to figure out if my unit operates typically or otherwise.

Thanks in advance.
big_katydid
cerrot's avatar
cerrot
1,700 posts
 
I think that it a reasonable expectation to buy decent gear and not have it hum. I also think there is alot of gear out there that people accept with hum thinking thats the way it is (not necessarilly) and that the hum doesn't effect the music (it does; everything effects the sound); I don't think most of us understand "quiet" and "black background" until you really experience it. And, reviewers comment on "quiet" but they usually mean the sound of the music and not mechanical sounds. If reviewers commented on the mechanical sound as well, we'd have a nice little game changer.
big_katydid OP
50 posts
 
Actually, as it is a very quiet morning I did test the amp, the hum does change a bit as you raise the volume (went to 12 oclock to simulate loud listening), however it is asymetric...it rises in the right channel and reduces in the left!

To be honest if my dealer asked me if I wanted to change gear I would consider it but they have a no return policy as they give home demos and as this is supposedly working to spec they might not accept that as a request. IT is a shame as the rogue sounds pretty good.
big_katydid OP
50 posts
 
I think what is perplexing about the hum is just how asymmetric it is: turn the volume up and it rises (slightly) on the right, reduces on the left, if you then turn the balance to the left the hum becomes much louder on the right but unchanged at the left. The hum from the right speaker in that instance really is audible from several feet away but in practice I can think of no instance where I would listen to the left channel only.

Anyway something for potential sphinx buyers to test when they audition the model.
big_katydid OP
50 posts
 
further to my last post, I have a rega brio in the TV room and the noise consists only of typical 'hiss', noticeable through the tweeter, little deeper in the mid unit and barely perceptible in the bass unit.

If I turn up the volume knob to maximum (no signal) there is no change that I can detect in the level of hiss and to the nature of the sound, it really does demonstrate to me how noisy the sphinx is, unacceptable by comparison.
big_katydid OP
50 posts
 
Reynolds853.

the transformer hum you described in the perseus, did that give any noise through the speakers also? Or was it only the hum from the unit itself? I do wonder if my 'variable hum' is related to that which I hear from the unit.
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