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
Big_katydid,

Regarding the hum you hear when you put your ear close to the amp, that may be normal. My Ayon Triton 1 has a very, very low hum that I can hear if I put my ear about six inches from the unit, but even then I have to listen closely. It is normal for that amp, so again, if you are hearing something like that then perhaps it is normal.

However, you also mention hearing a hum audible at 2 and 10 feet depending on the operation of the balance knob. That one I would have a difficult time accepting as normal. Again, if it were me I'd send the unit back.

With my M180s it was easy to ascertain that there was something wrong: one amp was quiet, the other had an audible hum that could be heard ten feet away. It wasn't a hum that was coming through the speakers, it was a hum coming from inside the amp itself. Concluding something was amiss was an easy call. I took the amp into the shop here, they called Rogue, returned the amp for repair, and that was all it was to it. As I mentioned before, we eventually got feedback that some bad transformers had made it into some amps so Rogue didn't really question the issue, they just took care of it immediately.

I would like to add too that when I had a Rogue system I always found them to have excellent customer service, from handling that transformer hum issue to replying promptly to my emails about tube compatibility. Though I have moved on with my system I still consider them a good brand and could only imagine they will give you an honest assessment if you get the amp back into their hands.

Regardless of how you choose to address the issue, I hope you end up enjoying your system.

Cheers,

John
Very quit since I sent it back. I had it maybe a week and sent it back. To much noise with the volume pot which was audible through the speaker, same issues I had with Virtue M901(which I enjoyed alot more).
Big_katydid,

I submitted a follow-up to my earlier note but it hasn't posted yet, so this reply may be redundant... we'll see which actually appears first.

A minor correction to your question, my amp was one of a pair of M180 mono blocks rather than a Perseus. The hum came only from inside the amp and was not transmitted to the speakers. The only sound coming through the speakers was the usual faint hiss from the tubes. Nothing unusual there. Once the faulty transformer was replaced both mono blocks performed flawlessly for the four years I owned them.

Going back to another of your posts, I wouldn't wait for the dealer to offer an exchange, I'd either tell them to get you a new one or handle returning yours to Rogue for inspection or repair. If they balk at that I'd call Mark O'Brien directly and tell him what's going on. But all of your posts describe an amplifier that I would not keep. They describe too, at least up to now, a dealer that I would be hesitant to keep too for that matter. Home demo or not, your dealer should work with you on getting this issue resolved. They may say that the unit is working to spec, but how do they know? Or get Mark O'Brien on the phone and ask him if this is up-to-spec performance standard. I've met Mark and visited with him for about an hour at a recent audio show. He proved himself to be committed to customer service when I owned a Rogue system and that feeling was only reinforced upon visiting with him. I told him that I had moved on from my Rogue system but wanted to take the opportunity to thank him for his support when I did own his products. I firmly believe that if you tell him that you are not happy with your amp, nor happy with the dealer representing him, he'll help you. Again, I would tell your dealer what you want done and if they don't help then go around them, and also lodge a complaint with Rogue about them while you're at it.

Good luck,

John
Big_katydid,

Glad to see that Mark got back to you. If he figures your amp is operating properly according to its environment then that would be good enough for me too.

Regarding your comment about extra detail and solid state, all I can say is that I think you might be surprised at the amount of detail that a properly set up tube system could deliver.

Glad though that it seems like the concern with your amp can be put to rest!

Cheers,

John
Reynolds853.

The transformer hum is audible close up, certainly not several feet away as was yours. The balance hum is more the issue, to be honest if I tried for an exchange with the dealer they probably would oblige especially as they also felt it was a bit noisy. However I do like the amp and find my system engaging (I actually got the amp after suffering a nait 3's excessive gain in the line input for years, actually not as I was using an attenuator! I finally had enough, bought the sphinx and am now able to listen to cd).

I'll probably ask mark a few more questions after the weekend.