Axiom Home Page Forums General Discussion Technical Questions Emotiva MPS-2 Amp hum/buzz questions

Hi, all.
I jumped in a bought this amp without first contacting Axiom. Well, it has a buzz and I'm (painfully slowly) working with emotiva to help me solve it, but I wanted to ask some opinions.

Here is the situation: I have a 7.1 channel axiom setup (m80s
front, qs8s surrounds, m22is rears, vp150 center and ep500sub). I use a denon 3808ci receiver and listen to hi-res sacd's dvd-as as well as 2-channel analog with a rega tt, shelter 501 cart, jolida phono preamp, oppo universal player and regular cd player and blu-ray player. I am trying out an emotiva mps-2 amplifier.

I am not loving this amp and thought I would, but this is probably tainted by the unresolved buzz. I wanted more quality and a lower noise floor, blacker background and all that from an amp. It does seem to play louder at equal volumes when compared to my denon 3808ci when it was used alone to drive the speakers. But. . . the amp is making a buzz/hum sound (lower now that I turned off a floor lamp, but still not what I like - wanted silent and expected silent, but maybe I'm ignorant about amps),
that is not acceptable to me. To me, the amp is not rich or warm
and maybe doesn't play well with my fairly bright seeming system. Have you any suggestions as to what will make me get the "wow" factor? The $1700 of this "bargain" amp is a lot to me. So, questions:
1. Am I expecting too much to have it at the least be quiet?
2. I'm on my third day with it and it seems to be growing on me in a way meaning I think I'd not like to go back to just the denon driving speakers (the sound is opened up a bit and seems to have plenty of power in reserve - just a feeling). Are my ears adjusting to it or the other way around? Still, listening to albums over the weekend, the amp made steely dan's donald fagan seem like he had a lisp as sibilance seemed to be showing through on Aja. I got fatigued (though maybe from dealing with amp issues and not being in the mood to listen to albums). Something was just a bit bright, but maybe the amp is allowing the axioms to show some brightness? Maybe the denon used to correct for this? I don't know.
3. If you were to advise me, what would you suggest I do? Anything to break it in? I saw how sirquack had substantial problems with it (ugh! after the fact of buying it myself!) Should I run some adventure movies through it to see if I'm going to have that problem too?
4. Should i look at different, better matched amps?
5. Will the axioms hold up as I go down this upgrade path? People on forums often suggest upgrading my speakers, though I have enjoyed the m80s particularly since I got them.
6. Could you just give me your opinions/ideas/suggestions based on your knowledge of axioms? I want more quality and to eke out every bit of music resolution I can. HT seems fine either way, but music is where I want to hear it all. Do you think my amp is damaged or that my home just has bad wiring (buzz
problem) and that any amp will be a problem? I am using blue jeans rca cables from the receiver to the amp if that helps. Thanks in advance for any help. I am quite frustrated at the moment. Finally - I sent much of this email to Alan and he kindly responded with a way to test the amp to see if it is an amp problem and gave me much perspective, but he suggested I post here as well, so here I am. Hope y'all can help. Thanks in advance. Wish I'd read here first, but made that impulsive leap.
Laura

It's not an Axiom problem since the buzz did not exist with the Denon. It could be a ground loop, it could be a bad connection, it could be a bad amp. I would suggest you work it out with Emotiva. I'm sure they'll take care of you.

I would start disconnecting every component one at a time and see if the hum/buzz stops. Is the amp itself making a noise if you put you ear right next to it?

For $1700 you should get more than "I hope I can get used to this." You can get a good selection of Amps used for that much - Bryston, Krell, etc. And I can't see why your home wiring would be the problem given your use of a powerful amp via the Denon before this Emotiva.

Laura, if even a floor lamp is contributing significantly to this buzz/hum, it would seem to indicate a shielding problem in the amplifier. An inaudibly low noise floor(which I assume is synonymous with "blacker background")should be routine with any competently designed modern receiver or separate amplifier, regardless of cost. The least expensive of my receivers(factory refurb, $151 delivered)has such an inaudibly low noise level and overall superb performance as an amplifier. It's unlikely that different amplification is something that will improve your overall sound quality, as that is determined almost entirely by the recorded material, as affected by your speakers and listening room.

You mention, rich, warm, and bright. It is one thing for people to say a speaker is bright, warm, chocolaty, etc. Speakers are probably the least accurate part of the sound reproduction chain, and can be designed with a particular voicing. Again preamps/receivers can EQ or have tone controls that will have some effect on the sound. The amp should be the thing that adds nothing to the signal. It has one purpose, to take in input and output it louder. An amp may make the bass tighter or transients snapper, but if you are expecting tone shaping you're looking in the wrong place.

The only thing which should have less affect on the sound is the cables.

Sorry - forgot to mention - the buzz is coming from the amp itself, not the speakers. Have reported all to emotiva and am waiting for some help from them. I appreciate the help in isolating the problem and will have to invest some time in this or invest in packing in up to send back. The connections are good (took my time in setting it up), but I have to move all the furniture back out to remove component after component. I have plugged it in different places and tried a cheater plug on it, but no change. Just now trying to see if it might just be one or more of the modules or what. Anyway, thanks for your help.

At this point in my ignorance/frustration, I think I am more interested in opinions on the value of amps with this system and the matching of amps to this system and perhaps any suggestions on a different way to go like a dedicated analog preamp with some sort of HTbypass and incorporating just a two-channel amp. Of course that may not help my sacd's/dvd-a's multichannel, sound better. Just asking as I should have on the front end - but I tend to learn by experience and learn well! Thanks for continued insight if you have some regarding this system and what I was hoping for.
Laura

THanks clubneon(also to Johnk and Zimm). Good info. to ponder as I think on this and plan for what to do next. Do any of y'all use amps in a denon setup or does the denon do it all for you? Maybe what I'm after in music would just be a very small improvement for too high a price? And, regarding speaker voicing, i have read that axioms are voiced more for HT, but I think that is from people who don't know axiom. Anyway - thanks for helping think through this.

First of all, why do you think you need an Amp, how loud are you listening and how big is your room. I have monoblocks for my 80's, but my room is 900 Sq Ft in size. That Denon should be totally adequate. Also, a speaker is not designed for music or HT applications, that includes Axioms. They are great for both.

I remember when my MPS-1 made my system buzz when I had the closet lights on, remember that everyone. MarkSJ?



Anyway, they sent me new amps with some reduced settings and it went away. Of course, I ended up sending the MPS-1 back as it kept having shutdown issues with the easy to drive m80's.

Axiom designs their speakers to be flat, to not emphasize any one part of the audio band over another.

If the amp is buzzing, that is almost always the transformer. The power entering the amp is not a smooth sine wave, and the harmonics are causing the transformer to vibrate. Some amp makers will embed the transformer in epoxy, or attempt to dampen it some way. Others say, "use clean power". If it is exceptionally loud there may be a physical defect either from manufacturing or something got jarred loose in shipping. Definitely see what Emotiva has to say.

The 3808 should be able to run everything just fine. What is it that you're not getting that you hoped the amp would add? Chances are you can improve things greatly by adjusting your speaker layout, and adding some simple treatments to the room.

My LPA-1 is as quiet and buzz-free as it should be. So your top-o-the-line MPS ought to also be hiss & buzz free too.

As others have said, the problem is in the amp, not the speakers. Emotiva should help you out with this. Have you been talking to Lonnie? I'm sure he'll be thrilled to talk to another Axiom owner.

Curiously though, one of the key reasons I returned the Emotiva LMC-1 (their inexpensive prepro) was that it *did* have a pretty high noise floor. Even at moderate volumes, from about a foot away from the speaker I could hear hiss and background noise. At high volumes, it was loud enough to hear from my seating position. Enough to be annoying, anyway. And no question it was being produced by the LMC, as my Pioneer Elite AVR on its own or paired with the LPA-1 is quiet (with the same M80's, obviously).

But do keep in mind that a 3808 will set the 'quality bar' pretty darn high.

Sheesh! What's up with all the Emotiva-love around here lately?

Is this the amp with modules, each module with it's own tranformer?

Try pulling out modules to see if the buzzing stop. It may be just one module.

Hi, again.

Thanks, Bugbitten, but I am hearing the sound from at least 3 or 4 of the modules and now I am getting frustrated, so will probably send it back and suck up the lost shipping money.

Sirquack, I have a room about 18ftX15 or so and about 9 foot ceilings. I think I wanted an amp to try to upgrade the quality of sound on my analog rig. Also, for "easier" amplification that wouldn't seem to strain. The denon didn't ever really strain, but psychologically (therein lie all the problems!) it seems better to have higher volumes at equal previous denon settings. I thought this would be a step up toward more audiophile listening. My jolida phono preamp did make my rega sound better and so did other tt upgrades, so I thought a system wide thing would be cool. What's not fun about new toys? So, now I'm actually trying to think before leaping and considering a dedicated analog preamp and amp and specifically the belles 21a and maybe an odyssey amp. Seems like they might mesh well with my wonderful axioms and then maybe down the road find a way to give the rest of my axiom channels some better amping for m/c sacd's and dvd-a's. But - I could be chasing a small improvement for big headache. The denon does sound good, I would just like some more oomph. Any thoughts, anyone, on the belles and odyssey type situation? If this seems like a good path, would an ss preamp be less troublesome than tubes? I have heard opinions about tubes, but was curious about what y'all thought.

Sorry I'm not too articulate about what I'm after, but it really comes down to getting the most out of the music in a realistic way and I wouldn't mind being able to crank it without fear of messing up something in the denon or speakers. I listen to pop, rock and jazz and usually either vinyl or hi-rez, though I also want to eventually get a music server in the system. I do stream via the denon and via Pandora, but usually as background music. I like to listen to albums, one after the other triggering different dj sides of myself and not getting fatigued as if I'm listening to cds. That is how the vinyl hit my ears last weekend, but I believe my mood was sufficiently pissed that not much would have sounded great. But never heard Fagan sound sibilant before. I could not get that buzz off my mind and it is grating on my as I type right now. It's not quite like fingernails on a chalkboard, but the background buzz is in the same category to my ears. Then, I also hate the hd-dvd sound and had to move one of my units to another room. Well, any insight will continue to be appreciated. Oh - and I get the feeling Emotiva is not too happy to deal with another axiom owner. I revealed this to them prior to the purchase when emails were returned quickly. Now that I have a problem, we are working at glacial speed, though Lonnie did just let me know it is indeed he who is responding to me and that emails would be returned faster from here on. Thanks everyone!
Laura

Randy loves him some Odyssey amps.

There is no reason an amp should buzz, regardless of the price. Since the amp is modular, it should be easy for Emotiva to send you replacement modules, and you can send the defective ones back.

I really do love my Odyssey monoblocks, they are darn heavy.

chapin99,
Sad to see you go through this,Emotiva will help you out and I don't think it matters to Lonnie that you are an Axiom customer because you are not having shut down issues.That being said I agree with you in your pursuit to improve your system.I'm on the side where 'I feel and so do my audio buddies' that my amp (Emotiva LPA1) has improved my system.We played the Dave Matthews/Tim Reynolds bluray in Dolby TrueHD through my buddies Marantz 6003 with and without the amp hooked up.We used an SPL meter, a blind fold, and also played the Marantz at higher volumes to dispell the louder is better theory.The presence and clarity that comes out with the amp is noticeable.The guitar strums and plucks really come out at you and when you switch to the receiver it still sounds nice but seems to recede back into the speakers,this is the best way I can describe it.I had similar results with my Denon 3300 which is why I kept the amp but it was nice to try it with a new receiver also.There are already many posts and opinions on this just thought I'd share mine and that there is nothing wrong with trying to achieve more Oomph!

And Gumption. What we need is oomph and gumption.

And a beer. In a tree.

Well. You've got a lot of gumption asking for a beer in a tree!!

And, I think if you ask for a beer in a tree, you should get it! Ha! Thanks all for supporting my quest for oomph. I finally got another email from emotiva and they say the buzz is normal for amps like this. So, I will be sending it back. I feel like I've read 4 books-worth of information online this past week and am still in pursuit of oomph, and a beer in the sun in 80 degrees on a pontoon boat. My newest thought today is that perhaps a very nice 2 channel amp would be good to start with and I believe I will have to ask about whether or not it is silent from now on. Do Bryston's (like 4bsst) play nicely with m80s? Interesting that they are both Canadian, but are they rivals? I have heard that the Bryston's are quiet and now I may be looking to that as a main feature (plus powerful). I use a Jolida tube phono preamp, so a nice ss amp might be good. Lots of choices - but scared to mess up again. Still - opinions are very helpful! Thanks! More beer and oomph for all!

Well, that should probably just be the mantra of the week.

Bryston makes very well-respected equipment. I've never heard anyone say anything bad about Rotel, and wid promotes his incessantly I've also heard people say good things about ATI.

Honestly, I think Emotiva just has overwhelming QA problems right now.

...and ATI builds Outlaw's multi-channel amps. If you are interested in ATI, and want to build up an amp over time, adding channel modules as you need it, go with ATI. If you're going to buy all at once, get the Outlaw. Put another way, if you like smaller payments over time, you can go that way with ATI. But if you're going to spend all at once you can save a little money with Outlaw; they just don't sell a partially full chassis.

I did not know that, Chris. Thanks.

Laura, we now know a good deal about your system. But I did not see any details on your room and setup. The amp problem is just that, an amp problem. You can get a new or used amp from many well known companies and not have to worry about the issues you have right now. Two channels would like do it, as the 3808 can clearly run the other channels. Open any audio website and the trusted names will be published and reviewed often - e.g., Parasound, Krell, Bryston, McIntosh.

But I'm struck by the fact you have the 3808 as a pre-pro. You are nearing the price of separates, and have separates, yet you have a wasted amp section in the 3808 and a sub-par pre-pro for the price. Why didn't you want a dedicated pre-pro? Just curious.

Given the general confidence that people have in the 3808's amp section, and the size of your room, I'm thinking you could use some time/money on speaker placement and room treatments. You are clearly willing to pay to get good sound, but no amp or tube will fix the first order reflections blurring your image, or the modes of your room causing muddy bass, etc. (It will fix loud, which I like!) Have you plotted the frequency response of your room? If not, try that. If/Once you have that data, you will find lots of advice here about how to improve your room to get the most out of what you have - which is plenty for an audiophile system, with or without a separate amp.

Just wondering Tom if the "Beer in Tree" was a reference to Bob and Doug Mackenzie's version of 12 Days of Christmas or was it simply the dream of a stout guzzling squirrel?

Take off you hoser!

Thanks, Zimm. I didn't go with dedicated pre/pro because I'm still learning and when I got the denon at least I knew it would be a great receiver with the proper number of hdmi jacks and good video stuff. Thought it would be the end of the road, but then I've kinda tweaked my analog setup and wanted to be sure I was doing what I could with that. I have a crazy setup and room is at a premium. I'll try to post an image somehow, but I also run a simultaneous quadraphonic system (wait 'till you see the huge La Scala fronts) with all that dedicated hardware (that is all upgraded and/or in great condition) and even a small panasonic receiver that now uses analog out of directv hd-dvr to drive my bose outdoor speakers mounted on my patio (old yamaha did this, but denon uses those two channels to run my channels 6 and 7, so bought used little receiver). I love my quad stuff when I'm in that mode, but I love my more pristine sounding 2 channel and hi-rez stuff when I'm in that mode, so I guess I have a nice system for a schizophrenic! I like what I like, so some people just wouldn't get it, but it is cool. Anyway, I digress. I will try to put a picture here and you might get to see my 1963 Ami/Rowe Continental Jukebox too (all this is why I have fun but not the savings account!). Thanks for the input, everyone, on amps. I'll be watching audiogon most likely - I'm scared to try anything with modules again, so will probably stick to the bryston-type amps. And, in the meantime, I may just find that the denon is fine. Oh - big thanks on the room treatment idea. I believe that will be a weak link and maybe hard to remedy - and wish I understood about the curve things, but all I have done is setup with audyssey (too many times to count). Someday I might get there. Thanks again. Happy beer in a tree!
Laura

Oops - I see you have to have some sort of url to post a pic. I have no idea about all that. I was hoping for a cut and paste type thing. If I figure anything out, I will post a pic, but doubtful. Sorry.

Laura:
Posting photos on the Axiom boards isn't too bad.

Open a free account at Photobucket.com. Check out this FAQ and the "Photobucket Overview" questions on the left. You'll want to make your photos smallish so they don't end up gigantic when posted.

After you've uploaded images, hover over the image that you want to post here in the forums. A little box will pop up under the image. Move your mouse over the bottom one and click it to copy it (on some computers it will copy the info as you click it, others you'll have to copy the info).

Now, in the Axiom forums, click "paste" in a text box when composing a message and it'll put in all the right info. You can preview your Axiom post to make sure it worked!

Laura, Zimm has given great advice yet again.

You can use photobucket to host pictures and then paste the img tags here.

Murph, it was both

Laura, after mentioning room treatment, I went to the RealTraps site to get a test tone generator for myself (free). I found a few videos that go through the basics of room treatment and might help you understand your acoustic environment better. Room Treatment With all due respect, as much as you appear to enjoy music and as much as you have invested, you can't hide from learning some acoustic theory at this point.

Before you buy that Bryston amp, review the videos and see if you notice any glaring problems with your room. You might find that some simple position changes, or cheap DIY changes can fix most of what you don't like. People with much bigger rooms find the 3808 to be a very good amp. For a small room, you don't need more power. It won't hurt, but unless money is no object, I'd bet you Adrian's M80s that your dollars would go 5 times as far dealing with reflections in your room. (and that would also benefit your Quad setup) I have been surprised at the improvement in imaging and clarity in my room with modest changes. (Although my response graph still looks like OJ's lie detector test results!)

Hey! That sounds easy. I will play with it tomorrow. I appreciate the heads up.
Laura

Hands off the M80s Feel free to bet my 28 yr old JVC/Sansui/no-name combo downstairs that is home to the various species of basement crawlers though.

Thanks again, Zimm. You are right - I think I need to open my brain to learning about this. Thanks for the link, I will check it out and I would be delighted to make some cheaper changes, especially when it will benefit all my music and HT hobbies. I guess all I needed was a pointer in the right direction. Also, for anyone still interested, I believe the customer service folks at Emotiva are going to work with me about the return shipping. This means so much to me that I just needed to let people know. (I'll know for sure next week to be 100% positive I'm hearing it right from them). It sure makes a person feel better about the company and it isn't like they just ignored me, so I have to say that I am happy with their customer service at this point, no matter how trying it has been on my end. Onward! I also look forward to posting pics of my unusual setup for y'all. Thanks!
Laura

Trying to post some pics - hope this works!

Holy cow. Look at all of that gear.

More - going around room (you'll note my sound issues in the room layout). Hope you enjoy and this isn't too irritating.

One last pic - camera hasn't cooperated that much: This pic is before I added the extra shelf to the lovan rack to the left of the tv. Also, when I had bellari phono stage (now I have the jolida). My room issues are that it is obviously dense with furniture, rugs, dog stuff; it has windows all around (I love them all!), short hallway enters rear of room and there is an open window-ish hole to kitchen and a door to the living room up front by the left la scala. Anyway, at least now you can see my simultaneous quad and stereo/HT system. Thanks for looking and telling me about photobucket! Oh - amp is packed and ready for return (took hours to uninstall modules and reconnect just denon).

Wow... nice setup....8-tracks even!! A woman after my own heart!

Thats a very nice room Laura. Actually, it dosn't look to bad acoustically. The bookshelves on the right side are great for diffusion and you have a fair amount of furniture to further break things up. You should get decent imaging in that setup.

And the dog looks to be a great source for absorption........................ of love!
Awwwwww!

Even the dog is colour coordinated with the speakers and the decor!!

Thanks guys! Yes, chapin the gimpy wonder dog is color coordinated! Never thought of that!

And, in case anyone has followed this whole saga, here is my latest: I do not miss the emotiva. I started listening to the music more than analyzing the sound last night. I think the denon somehow does a great job running all the speakers. I listened to several m/c sacd's and they sounded great. My take on the amp thing is to get more oopmph, turn up the denon volume. I really thought I'd miss the emotiva, but I don't. I wish I knew what a fine 2 channel amp would sound like, but I am going to be fine without it. If anyone is going down this path, I'd suggest they stick to axiom amps (we know the axiom quality and customer service and they will surely play well together) or demo some locally. In the end, I guess it is a personal issue, but the expense, in my system anyway, is too much for too little gain. I don't know what I am missing, but I'm now thinking that on my budget it's probably not worth worrying over. To my ears, the denon/axiom sounds great. I'm sure upgrade-itis will still rear its ugly head, but maybe I can just live vicariously and enjoy what others find in their pursuits of better sound. Thanks for all the help.

Laura, sorry I missed this earlier. I have an Emo MPS-1 amp and now that I've got the bugs worked out, I'm a happy camper. Most of the bugs were due to other problems, but I didn't find the one Emo problem until I fixed the others. Before I put the sound system together, I decided to go "green" throughout the house and I installed compact fluoros. When I put the sound system in the buzz/humm was deafening. I tracked most of the humm to the ground screw on the EP500. The next biggest humm came from a ground loop issue with the cable for the TV. One of Axioms isolators did the trick there. Then I figured out that the compact fluoros in the room (and a few others on the same circuit) were the last cause. THEN I found the problem with an Emo amp module. Not a humm or buzz, but more like a lit fuse; a sort of crackling hiss. Emo took care of this without question.

Sounds like you have a solution, though.

Scott

Laura, your room looks like an oasis of sound. I would make one suggestion that should cost less than the Emotiva amp, but ask that other comment before you would act, as I am no expert. But the hardwood walls and glass are the likely cause of your dissatisfaction. They look great - I love wood - but you are getting reflections going that won't end any time soon. My suggestion: consider putting a heavy drapes along each wall. you can open them when you want, but during critical listening, they will keep the image clear. Cost is dependant on style and DIY skill, but for less than a new or used amp I think you could up your sound quality dramatically.

Hopefully other will jump in, but you have the makings a great oasis, but you are dealing with a room almost as active as the hypothetical cement bunker used to explain echos and reflections. But a new amp won't fix this. You have to kill the reflections and the improvement will floor you.

Beautiful system, house and of course dog...

Can't help but love the doggies.

Never mind, I figured it out. My math was waaaay off. Upon further calculation, it looks like the real problem is the glass of wine. By my estimation, it is about 76.84% too full. Correct that, rinse and repeat, and the problem should be fixed.

Worked at my house anyway!

Ha! I agree and I like the rinse and repeat remedy - will try that tonight. Glad you noticed - funny that made it into the pic!
Laura

As someone who has followed Laura's posts on AVS as well as here, I have to give a big group hug to everyone here who tried to help out.

While the AVS Forum quickly devolved into an argument about amplifier quality and then split into fifteen different unrelated discussions, you guys actually worked through and tried to help Laura solve the problem.

Laura - for what it's worth, I think you made the right decision and should be happy that you figured out you don't "need" the amp while you could get rid of it for only the cost of shipping. Plus you now don't have to play the "what if" game with yourself and can be happy knowing you've got a great sound setup. Upgraditis can never truly be cured, but at least you've generated temporary immunity to separate-amps-disease.

Jason

PS: Some of the things I hear about Emotiva's customer support are amazing. "Noise like this is normal in these kinds of amps" What?!

Yeah, that was surprising. I know several people here have Emotiva and are problem free, but some of the tech support comments are truly out of left field.

Thanks myrison! I agree about how helpful folks are on this site (and persistent!). Yes - I think I have a temporary cure.

Laura,

I have had my MMC-1/MPS-2 setup for over a year now (using only two channels at this time) and the sibilance in the upper frequencies of the audio range still exists.

Separate from that, I also have a hum coming from one of my modules. Lonnie from Emotiva assured me that the root cause of this hum is electro-mechanical and does not have effect the quality of audio. Even so, he offered to replace the module causing the hum. In my case the hum was only audible within a foot and with dead silence so I didn't bother to tear apart my rig.

The sibilance however continues to grate on me. A flagship amplifier shouldn't sound like this. I have read great reviews of this amplifier and its predecessor (MPS-1). It could be bad modules but something tells me no since it occurs across both channels. I am afraid it's inherent in the design.

So you ended up sending yours back? I do not have that luxury now that I am a year+ into ownership. Maybe I'll hit up Emotiva support again and see what they say. Did they have any comments for you as to the cause of the sibilance?


Thanks,

Paul