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
i see Steve guttenberg talks with the sphinx designer where he says some V1 units (1-2%) had an issue with noise related to DC offset? anyway not sure if that was something that could have been rectified back then but aggravatingly I did trade mine at a loss simply because of that very high noise floor. I enquired with rogue about this and my dealer back then, I should have been more aggressive on trying to get a refund. The only time I really felt like I'd been let down by a product in my audio.
I have a Rogue Pharaoh hybrid integrated. Have had it for 3 years now and have had zero problems with this unit. It has a tube preamp section. Any tube amp will produce some residue hiss. This type of hiss is so faint in my amp that you have to put your ear up to the  speaker to hear it. If you listen to your speakers with your ear up against them, well, I guess you might have a problem.

boband212, I have listened to the amps you talked about and have had the opposite impression. The Rogue Pharaoh will blow that Chinese stuff out of the water....IMHO...lol
i have a marantz intergrated amp. it is dead quiet. humming amps- not so good. at least not for me. i do not want a humming, nor buzzing amp. sometimes s problem with a tube, sometimes a ground problem, sometimes a resistor, and usually a problem with a transformer. i have very sensitive speakers and no noise at all from the marantz amp. at the same price range i believe marantz would be a better buy. or even yamaha. rogue has their problems, but they are riding high on that made in usa wave. I will also say that listening to the cronus, and to a Jolida Fusion 3502S amp at a dealer in Indy the 3502S had a nicer sound quality. Rogue is maybe over rated. There are many dealers and companies offering great service. Thanks for the posts. Not nearly so many consumer reviews of this amp as for the Jolida JD1501BRC amp. Now I will cross Rogue from my list. Focus on a Yamaha or Jolida amp. Thought about a Jolida JD1501P hybrid power amp with a Schiit preamp. Or a Yamaha A-S1000 amp. 
Yes, Sphinx V2. It is not my main amplifier, but used on my computer workstation with Magnepan MMG that are 4 feet behind my desk. I can hear a hissing noise that is present all the time, and when increasing the volume knob the hissing noise takes on a higher frequency overtone. The tubes are new production, low noise and microphonics selected.

My previous class d on the workstation was a Peachtree Nova 220SE, which was quiet, but lacked emotional involvement, and with 33 months of usage the power input relay died so it cannot turn on.

My main system has Magnepan MG12 with two ampflification options. AES Sixpacs, or class d Channel Islands D200 with a Primaluna tube preamp. No hissing noise in either case there with class d and tubes, as they are separate chassis.

In every class d amplifier, I’ve always used adhesive ERS sheets on the interior of the chassis. As the adhesive version fullsheet is hard to find these days, I have not been able to apply it to the Sphinx V2 yet to see if it makes a difference.
To go a bit further.

I did feel a bit burned with the noise issue on the amp, Rogue suggested it was a product of implementing valves and class D, unfortunately my dealer had a no return policy after home demonstrations, I did not notice it until the unit was purchased (I did not at that point check amps for noise on demo) I probably could have got a refund/exchange had I argued the noise issue but stayed with it as in practice during use it was not noticeable when sitting away from the speakers.

I accepted that amps will make some noise, until checking out the aforementioned NAD, it was easily the quietest amp i've (not) heard. My old naim nait 3 by comparison gives a slight audible hiss.

Hopefully sphinx V2 has fixed the hum/buzz and it is perhaps telling that V2 comes so very quickly after the release of the original model. I'm surprised such an obvious flew was not picked up prior to release of the original. It is disappointing as had the sphinx been quiet I would no doubt still own it.
I have yet to purchase a replacement amplifier, for the time being I am using some pro equipment to run my speakers.

Jspively, apparently the original version sphinx does have this noise issue, some may not object but in comparison to say a NAD 365BEE that I auditioned it is very noisy, the NAD is almost dead quiet even with an ear to the speaker (at least with my ears). The sphinx does run very cool though which is a plus.

When I audition an amplifier now I check it for practicality first: noise, good use of the volume rotation (I hate sensitive designs that jump to full power almost immediately with loud CD's), heat.
Had this amp, had this same problem, and returned it. The noise increases when you turn the volume up or down right?
Hi Everyone -

I purchased a used Sphinx a couple of weeks ago. I'm enjoying the amp paired with my KEF LS50's. However, I stumbled upon this thread after researching Sphinx hum/hiss/static.

The actual unit is dead quite but there is an amount of static coming from the speakers that wasn't there with my previous NAD amp. It's only audible a foot or so from the speakers. It increases with volume change but not significantly. I have noticed when balancing all the way to the left, the right channel becomes more audible.

I guess the main question I have is if this is attributable to the normal "noise floor" of the amp? It is minor.. but it is there. More curious to know if the amp if preforming as it should.

Any insights would be greatly appreciated. I'm awaiting a response from Rogue Audio as well.

Thanks,
Joe
What did you end up buying? I was looking at integrateds and researched for a year and have a lot of data if you need it. I travel and was able to look carefully at many different products.

I found that a pure tube amp would be the only way to go.
Thanks for following up on the thread. I was wondering how it turned out. I, too, gave up on the Sphinx in pretty short order for the same reason. Hope you find something that you enjoy.
A late follow through to this thread. I did unfortunately abandon the sphinx primarily because of the noise issue, I feel it is an otherwise competent unit but that level of noise was simply unacceptable, a sub $1000 NAD unit by comparison was practically silent. The sphinx comes in V.2 now and is described as having a lower noise floor, I wonder if this is a remedy to the hum/hiss of the original. I'd recommend the sphinx still but if an asymmetric hum/hiss concern you from speakers then I would check the level on the original version carefully.
The Sphinx is an entry level model, so I wonder if Mark would do any mods to it. With the Magnum models he upgrades the caps, power supply and adds cardas wiring.
Food for thought.
Low I didn't have time to compare in detail including noise levels but both sounded quite good. Pharoah is 3X the price and a good bit larger so to be expected. My dealer who traditionally sells a lot of reasonably pricey tube gear indicated the Pharoah was his absolute favorite sounding amp, which is saying a lot. Pharoah would be a reasonable choice to downsize my main setup where I have lesser need to downsize currently. Sphinx would be for my second system in teh family room were I to pull the trigger. It would fit into my cabinet there and allow me to forgo the TAD Hibachi monoblocks sitting separately on the floor crrently. The possible noise issues reported would be my only concern. I may just stay on the bench for now. These things will only get better over time.
Mapman, no contest between the Pharaoh and the Sphinx. The Pharaoh measures up to Rogue's high-end gear. You won't hear any complaints about hum passing thru the balance control. lol.
Got to hear the Sphinx and pharaoh yesterday. Liked them both very much. Both were a bit larger than I expected but we're a lot of quality product for the dollar. Am considering downsizing my second system to an integrated and the rogues checked all my boxes.
Man, I was contemplating buying a new Sphinx or a used Audio Research VSi-55 for slightly more money. I ended up going with the Audio Research. I feel like I dodged a bullet. The Audio Research is dead silent.
BTW, if the transformer hum turns out to be DC on the line, there is now the Humdinger from AVA, that does what the Humbuster does (reportedly even better). If DC on the line isn't your problem, then it won't help you. But they have a 30 day return policy
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.
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
I'll agree with Donjr, the customer service response is excellent.

Mark O'Brien did email me this morning. He suggests that the grounding for tubes and class D to be tricky and that in different environments there may be noise at the balance. He reckons that any sphinx in my set up would do the same. Perhaps its not ideal but as long as my unit is operating to spec then I can be assured that at least at future upgrade I can say it's working to spec.

On the topic of rogue I did also home demo the cronus magnum but I found it quite mushy sounding compared to the sphinx, maybe I'm not destined to be a full tube fan. I was actually surprised just how much softer the cronus was compared to the sphinx, still it made a street harp players recording sound incredibly seductive instead of biting.....and it made thinner or bright recordings much more manageable, but overall I prefer the more 'direct' sound of the sphinx.

I think being so used to SS that I'm used to the extra detail, plus im not sure I'm ready for hot 60lb metal and glass in my house!!
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
I have a Rogue Cronus Magnum and have had it for years. It's been a perfect amplifier. I've been in contact with Rogue several times with questions and their customer service has been excellent. Devil boy's comments are the first negative comments I've ever read about Rogue anywhere.
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.
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.
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.
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.
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.
Devilboy: so did the guy you sold the unit to actually get a repair?

I will give some feedback to my audio dealer (with the same noise in their unit) as to Rogue's response.

In this situation some people could insist on a return but to be honest the noise does not affect listening as it does not rise with volume increase. I think what bothers me is that there is some noise there and it's seemingly a tolerated part of the design which I think is sub optimal, in practice its not noticeable but the mere fact of its presence would bother many. In future I may just make sure that in any amp demos I actually get my ears up to the unit/speakers and play with the knobs a bit before I listen to anything playing!.....
Foster_9... "some noise from the balance is normal." Ridiculous statement, don't you think?

Yes, Lowrider that is totally unacceptable, from a quality control perspective or any perspective.
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).
Joekapahulu, you would be wise to. How is it that two regular guys like myself and the person I sold it to heard two different problems immediately but the pros who built the thing didn't after having it for five days? Thankfully Rogue is not charging him for the "second" repair however I do believe he had to eat the shipping cost to send it back. ????????? Really Rogue? Come on.

As you said Joe, that's something to think about considering where you live.
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
I'm glad I opened this thread at the very least it will make people aware of sphinx's noise and they can check it out for themselves specifically, it's the type of thing I wouldn't have thought of noting on a demo.
I will be watching this with interest. I had been planning to get a Rogue Cronus Magnum direct from the company. Living in HI, I have no dealer and have been unable to hear the unit. I was going on rep and reviews. But the last thing I want to face are product and return issues it's too expensive and a hassle. I am now apprehensive over Rogue QC? I know that may not be fair but when I spend $2500 on some kit, I expect it to work as anticipated and represented. I want to know customer service will be supportive.
Foster_9... "some noise from the balance is normal." Ridiculous statement, don't you think?

I've auditioned several preamps and an amp and the only noise I've ever heard was some hiss, and that came from the type of tubes being used.
I did ask Rogue if in their opinion the noise was an issue, Nick feels that the amp is working as it should saying that some transformer noise is possible and that some noise from the balance is normal.

I still have a three year warranty and unless there is a consensus from sphinx owners of a problem that is apparently fixable (say if somebody had the same issue and Rogue fixed it)then I'll currently accept the amp as it is, if the problem is noted later and is confirmed as fixable then I will look into it again.
"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'."

It's a new unit. That's all that matters. Don't settle for less than a unit that is doing everything you expected. Rogue needs to make it right. You don't need to be buying devices to quiet it down. Transformer hum needs to be eliminated and noise through your speakers needs to be eliminated by Rogue or they need to replace your amp. This is my opinion of course. It's ultimately up to you.
"Humbusters" are discontinued, but I found mine after searching around a bit so they're still out there. Great bit of kit as they say.
lowrider57/Reynolds853.

interesting that your two issues cover both of my units observations and both were repaired. (The testing was thorough, cables/speakers were switched, even different power cords used.

I'll see how Rogue responds next.

Thanks.
My final thoughts on the matter...the transformer hum seems to be in the design and it's not a deal breaker. You'll only hear it when the amp is idle and maybe not at all from your listening position.

However, no amp especially new and in spec should deliver hum thru the speakers. We know definitively that it is coming from the amp since you have repeated the problem when using the balance control. (I hope you have tested this by swapping cables).

I have read many threads regarding the Sphinx and nobody has ever mentioned hum and my suggestion is that instead of asking Rogue, you tell them you are sending it back for service. If you don't have the unit repaired, you will never in good faith be able to sell this amp if you decide to upgrade.
I've emailed Rogue again and as both units demonstrated the various noise I have asked if they think this warrants a return, I guess the ball is in their court so to speak, there is plainly an audible hum and the odd unequal hum from the speakers, if that is enough to convince Rogue their is an issue then so be it and I could send the unit to be checked/repaired, part of me does think that maybe that is just the design of the unit, admittedly that's not optimal but I'm currently not willing to start playing around with retail returns over something that doesn't actually affect my listening, I do however understand how some would not find it acceptable, $1500 is not crazy money but you still expect a quiet unit, there are plenty of cheap amps that are silent.
Big_katydid,

I had a transformer hum issue with one of my M180 amps. I sent the amp back to Rogue and they replaced the transformer. After that the amp was fine for the entire time I had that system.

Rogue said too that they'd apparently had some bad transformers make it into some amps. Regardless of whether the other amp in the store was noisy, I'd send the unit to Rogue for inspection or repair.
Yep, don't convince yourself the speaker hum is acceptable, as your pre should never have left the manufacturer exhibiting hum. Gear is just too expensive not to work perfectly, and that means no hum.
Big_katydid; Transformer hum does happen with some amps and you should try to find a device like the PS Audio Humbuster (which I believe is discontinued).

As for the volume control related hum, I would send this unit to Rogue for warranty repair. This very similar hum on my preamp was the result of a faulty part. Rogue does not make the volume or balance pots, they buy a batch of ALPS pots. They may tell you to swap out the tubes and clean the contacts and other troubleshooting tips, but in the end, this is their problem.

They are a very reasonable group of guys and they want their customers to be happy with their products, so they should have no issue with servicing the unit. If it was me, I would tell them this hum was unacceptable.
So an update on the humming sphinx.

I took it to the audio store and compared it to their shop floor model, both units demonstrated the same unit hum and noise from the speakers. The conclusion by the store associate was that it was a bit noisier than he expected but hadn't especially noticed though I think he had noticed the hum from the left speaker was louder than that in the right. He felt the unit hum was the transformer but was a bit perplexed by the hum from the speakers especially how the hum increased on the right side when the balance was turned all the way left!

Anyway I will assume for now that the unit is operating to spec even if it a bit noisier than ideal, I have provided Rogue with the details, although it is interesting that Rogue felt the amp should have no noise but the two units examined do give off some noise.

Only if the balance control was turned entirely left would the hum be audible over quiet music at close listening, in practice I don't use the balance anyway so it is not an issue. Overall I feel the sphinx could be quieter but for me the noise does not affect the music, it is simply not loud enough. Maybe Rogue could change something in the amp to quiet things down a bit in the future. If I had been more aware of the noise upon initial demo I might have been persuaded to try quieter models but as it stands I like the amp so its good for now.
From Simao: "Hell, my MLA Statement hybrid integrated (originally $11500) has some hum when it's on. Does it screw up the music?"

Ummmm.....yes, it does.

My Rogue had a hum so easily heard from the listening seat that it was actually distracting. Any amplifier I've had that had a hum was distracting. To me it's like listening to vinyl with all the clicks and pops....sorry, I don't want to spend my money listening to that.

Also, let me make another thing perfectly clear. In addition to the hum, the Rogue made "swooshing" and "popping" sounds from the left channel with or without music playing. There was obviously something defective with the amp. Not just transformer hum. I'm with Wolf. I detest ANY noise other than music coming from my speakers. It's way to distracting and removes me from the emotional connection.

I was at a friend of a friend's house about 15 minutes from my home about a month ago. He has a system that retails for somewhere just south of 300K. He played vinyl on his $30Kish 'table. Every album he played sounded like crap. Yes, garbage, because of all the pops. Way too distracting.