klinemj
Emo VIPs 
Official Emofest Scribe
Posts: 15,088
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Post by klinemj on Jan 5, 2017 17:23:37 GMT -5
AMPS shouldn't sound different but I have found this to not be true. Not saying more expensive means better but I can hear a difference between my QSC USA 900 and my PS Audio cx amp. THe PS Audio has a much fuller cleaner sound. The QSC isn't bad but I can say it doesn't sound nearly as good as the PS audio does. Fan noise is a issue for me with PA amps and actually the reason I'm looking for a new amp. I currently have a mixture of Crown and QSC amps for my base 7 channels and a Carver 5 channel for my atmos speakers. The PA amps have lots of overhead which I like but the fans are a big issue for me. Haven't heard Odyssey amps but they look really nice as well pretty big price jump from Emotiva though. 3 channels for the price of 7. Would probably be out of budget for me at this time. Generally, I agree they should not sound different. In my experience, the Emotiva amps tend to offer great "real" power per $. I did find, with my XPA-2 gen 1 that there was a little bit of upper end harshness, and that went away with my nCores. From all I have read, the gen 3 should also solve this. Frankly, having lived with smps for a couple years with my nCores,don't worry about the power supply not keeping up. That said...loving tubes these days! Mark |
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Post by leonski on Jan 5, 2017 18:00:14 GMT -5
I'll be curious to see how many years it'll take for the SMPS myth to finally be accepted as busted. What is the SMPS 'myth'? That it is good as a well-designed linear? That is ISN'T as good? Makes noise? Doesn't have as good a dynamic power as a good linear? (this one is apparently true) Or? Fill-In-Blank? |
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Post by Casey Leedom on Jan 5, 2017 18:03:14 GMT -5
Amplifiers "shouldn't" sound different, but some of them do even to untrained ears. Some of those measurements have real impact. For instance, want really nice clean, controlled, punchy bass: pay attention to Damping Factor and Slew Rate, not just absolute power.
When I first got my MPS-1 way back in September 2007, one of the 7 EPM-300 Power Modules had a very slight hum. (The module itself, not the amplified signal being sent to the speaker.) This gave me occasion to call Emotiva which resulted in a replacement. I mentioned on the phone to, I think it might actually have been Lonnie, that the MPS-1 made my Vandersteen sound so much better, especially in the bass range — I felt like I had new speakers! He, whomever it was, responded regarding the effect of having decent Damping Factor.
And a lot of amplifiers sound different because they're explicitly and unapologetically not faithfully reproducing an amplified duplicate of their inputs. And some people like that sound. In the end of the day, it's what you like that counts. There is no difference between the smile of someone eating a Grilled Cheese Sandwich made with American Cheese, and that of someone eating Fillet Mignon at a high-end New York Restaurant: they're both Really Happy, and neither one is "better" then the other in this metric space.
Casey
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Post by leonski on Jan 5, 2017 18:16:15 GMT -5
All this talk, discussion and debate about different amps sounding different is a bunch of hogwash. To me, it's no different than the argument about cables, ie. Monster cables vs. Monoprice cables, and on and on. $5 vs. $500. Which is better, etc. etc.
Yes, there are differences, miniscule, and most unnoticable to the human ear (although maybe not to the human brain!! :-)). An amp's purpose is to amplify sound, not color, change or modify it and any decent amp will do just that and nothing more!!
I've been running Emotiva amps since the beginning and have never been able to tell the difference in sound from any of them. Last year, I experimented and sold a couple of Emo amps and purchased a Carvin amp for my surrounds and a QSC amp for my fronts. No difference in sound or quality. The only difference is in the fan level noise. A bit higher on these amps when paying attention but still unnoticable when listening to music or watching movies.
Just my thoughts!! 
AMPS shouldn't sound different but I have found this to not be true. Not saying more expensive means better but I can hear a difference between my QSC USA 900 and my PS Audio cx amp. THe PS Audio has a much fuller cleaner sound. The QSC isn't bad but I can say it doesn't sound nearly as good as the PS audio does. Fan noise is a issue for me with PA amps and actually the reason I'm looking for a new amp. I currently have a mixture of Crown and QSC amps for my base 7 channels and a Carver 5 channel for my atmos speakers. The PA amps have lots of overhead which I like but the fans are a big issue for me. Haven't heard Odyssey amps but they look really nice as well pretty big price jump from Emotiva though. 3 channels for the price of 7. Would probably be out of budget for me at this time. FIRST and LAST: Amps DO or rather CAN sound different. And here's WHY/ Amps may be classed as 'power into a resistor'. In this case voltage and current RISE and FALL together. The 'waveform', as it were. Nice? Easy? Convenient? Yes to all three and utter BS. This is why specs should be ignored, mostly. BUT. All amps which measure the SAME or just for the sake of argument, within maybe 2db of each other will NOT provide the same power into a REACTIVE LOAD. Speakers can look like a capacitor or an inductor to an amp, depending on frequency. Add in the fact that a speaker may have an impedance which ranges from 2 or 3 ohms to 16 or even 20 ohms and there 'ya go. Have a good LOW impedance dip at the same place as a good high phase angle and THERE YOU GO. The amp is 'incapable' of driving the load to the level needed for the REST of the bandwidth. Distortion might be the least of your worries at that point. EVERYBODY on these forums thinks they have a 'difficult load' for a speaker. This is also nonsense, especially since most HT speakers are designed to NOT stress an amp to its max. This feeds the idea which I TEND to agree with that most amps which are NOT STRESSED Can and DO sound pretty much alike. It is at the fringes of performance that the differences become apparent, and not always to the good. Try a couple different amps with some REALLY reactive speakers. Like THIS speaker: www.stereophile.com/content/bampw-800-diamond-loudspeaker-measurements#twjo4Z595B5XZUiA.97And while it IS a 90db sensitive speaker, that don't mean beans when you start looking at the reactance to impedance characteristics. Just look at the first graph and read the first couple paragraphs. |
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Post by thxultra on Jan 25, 2017 11:35:24 GMT -5
Finally pulled the trigger. Ended up getting a XPA-2 and a XPA-5 used. Really wanted to stick with a traditional class a/b design (Class A would have been nice but a bit out of budget). Looking forward to getting them they will be my first Emotiva products. Always read rave reviews so excited to get these. Thanks everyone for all your help.
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Post by leonski on Jan 25, 2017 13:45:48 GMT -5
Finally pulled the trigger. Ended up getting a XPA-2 and a XPA-5 used. Really wanted to stick with a traditional class a/b design (Class A would have been nice but a bit out of budget). Looking forward to getting them they will be my first Emotiva products. Always read rave reviews so excited to get these. Thanks everyone for all your help. You couldn't afford the shipping on 7 channels of real class 'A' amps. Figure AT LEAST 2lb per watt or more. Not to mention needing several NEW runs of power Each on their own breaker. The new line of Pass amps are very heavy. The XA60.8 which is a VERY high bias A-A/B design tips the scales at nearly 90lb. For a mono block. For your 7 channel application? Over 600lb. Don't let the 60 watt 'rating' fool you. Real power is maybe 4 to 6 db higher. And will drive ANY speaker, including electrostats. High Bias 'A-A/B' is another matter. Not to mention the Electric Bill needed to run 'em. 'A' amps have huge idle current (not doing anything) demands. They are a little lighter, perhaps. I think you will be quite satisfied with your new XPA amps. |
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Post by thxultra on Jan 25, 2017 14:21:02 GMT -5
Finally pulled the trigger. Ended up getting a XPA-2 and a XPA-5 used. Really wanted to stick with a traditional class a/b design (Class A would have been nice but a bit out of budget). Looking forward to getting them they will be my first Emotiva products. Always read rave reviews so excited to get these. Thanks everyone for all your help. You couldn't afford the shipping on 7 channels of real class 'A' amps. Figure AT LEAST 2lb per watt or more. Not to mention needing several NEW runs of power Each on their own breaker. The new line of Pass amps are very heavy. The XA60.8 which is a VERY high bias A-A/B design tips the scales at nearly 90lb. For a mono block. For your 7 channel application? Over 600lb. Don't let the 60 watt 'rating' fool you. Real power is maybe 4 to 6 db higher. And will drive ANY speaker, including electrostats. High Bias 'A-A/B' is another matter. Not to mention the Electric Bill needed to run 'em. 'A' amps have huge idle current (not doing anything) demands. They are a little lighter, perhaps. I think you will be quite satisfied with your new XPA amps. Ya if my wallet allowed I would have liked to have gone class A on my mains. Pair of XPA-1's may be a option one day... Don't think my air conditioner would be able to keep up with 7 channels of class A power even if my wallet and electric could... Really looking forward to my new XPA amps as they will be replacing some Crown and QSC amps which while nice for PA use have fans that are way to loud for Home Theater/ home music listening. Had them on hand so used them for the time and they served me well but expecting a huge jump in sound quality with the new XPAs. Still need a 4 channel amp for my in ceilings to replace the old carver I'm using now but that will be a project for a later date.... Maybe a BASEX or another XPA... |
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Post by Casey Leedom on Jan 25, 2017 14:51:10 GMT -5
The incredible Weight/Watt of Class A amplifiers might be addressed with the Krell "iBias" (and what looks like a similar scheme Boulder), where they do Current Feedback to adjust the bias on the output devices. This seems to be a take on wanting Class A benefits, but not the Class A high Idle Current. Apparently this differs from Class H topologies where the input signal is measured to rapidly change the Voltage Rail. Instead the circuit measures the actual current being drawn by the reactant speaker load and uses that to change the bias on the output devices. I'm sure someone like KeithL or Lonnie could offer a far more complete, accurate and technical commentary on this. Casey |
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Post by vcautokid on Jan 25, 2017 20:15:47 GMT -5
Actually I have been following Odyssey Amps for a long time. Got to talk to Klaus a few times. Real nice guy, and down to earth. That was a few moons ago. But yes, Odyssey is in my "yeah that is good 'un". |
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Post by hpc on Jan 26, 2017 19:31:27 GMT -5
I would look at the XPA-100 as the competitor to the Stratos mono and the XPA-200 as the competitor for the Stratos stereo. The Emotiva amps are half the price but unfortunately they have been discontinued.  XPA-100 I have the XPA-200; nice amp, good price. Sound-wise - cannot hold up against the Odyssey Khartago's and don't even think about it being comparable to a Stratos (even a base model). I have both the Khartago monoblocs and the Stratos-Kismet (hybrid - Kismet internals in the larger Stratos chassis). AND Odyssey offers upgrade paths for all of their amps; EMO, not their business model. |
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Post by teaman on Jan 26, 2017 19:58:52 GMT -5
Personally I sold my Outlaw amps as I found they lacked dynamics and punch compared to my Emotiva amps. I have had plenty of failures in my Monoprice cables and inexpensive items, to the point that I would never drop that kind of money on their product. ATI would be another company I would look into.
Tim
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Post by Casey Leedom on Jan 26, 2017 20:27:57 GMT -5
I thought that the Monoprice amplifiers were just rebranded ATI amplifiers ... is that not true?
Casey
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Post by rdperry12 on Jan 26, 2017 20:34:29 GMT -5
ATI makes the Monoprice amp and the outlaw amps. They also make the Cary and Lexicon amps.
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Post by thxultra on Jan 27, 2017 9:49:37 GMT -5
ATI makes the Monoprice amp and the outlaw amps. They also make the Cary and Lexicon amps. Correct the Monoprice amp seems like a great deal as well. I heard the outlaw amps have bigger power supplies then emotiva and more output transistors which people say sounds better. Pretty sure I'm going to be really happy with my XPA-2 and XPA-5 though especially going from some older crown and qsc pa amps with loud fans. Getting rid of the fan noise is going to be huge. Odyssey stuff looks really nice but a big price jump as well. |
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Post by leonski on Jan 27, 2017 13:19:08 GMT -5
All depends on your speakers. And listening habits. And the room.
Bigger / Louder and Less sensitive all make demands for more power on any amp.
If you had a pair of the some 100db sensitive speakers, you could probably make due with 10 or 20 watts per speaker and STILL get evicted.
Are the Cary / Lexicon amps the 'same' as ATI or made from different designs?
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Post by leonski on Jan 27, 2017 19:48:22 GMT -5
The incredible Weight/Watt of Class A amplifiers might be addressed with the Krell "iBias" (and what looks like a similar scheme Boulder), where they do Current Feedback to adjust the bias on the output devices. This seems to be a take on wanting Class A benefits, but not the Class A high Idle Current. Apparently this differs from Class H topologies where the input signal is measured to rapidly change the Voltage Rail. Instead the circuit measures the actual current being drawn by the reactant speaker load and uses that to change the bias on the output devices. I'm sure someone like KeithL or Lonnie could offer a far more complete, accurate and technical commentary on this. Casey H power supplies will have 2 or more power rails at different voltages. maybe 15v, 30v and 45v. or just 2 rails. iBias sounds like a scheme to adjust bias IN TIME to the music. Carver did this (or similar) with his tracking power supply and his earlier 'magnetic field' PS. In either case the PS stored Very Little energy (no huge PS Caps) and turned the PS on/off in time to the music. If iBias works, it'll cut down on how much heat sink you need and the electric bill a full 'A' amp can generate. 2 different things. iBias works on the output transistor bias level while the H power supply makes avaialbe higher voltages instantly on demand. I'm a little leery of anything that even feels like MORE FEEDBACK, which the iBias certainly has. I may look up a measurement oriented review to see how it does and if you really can have a class 'A' amp that doesn't weigh a ton and come with enought heatsink to cool a house. |
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Post by charlieeco on Jan 28, 2017 0:34:27 GMT -5
All depends on your speakers. And listening habits. And the room. Bigger / Louder and Less sensitive all make demands for more power on any amp. If you had a pair of the some 100db sensitive speakers, you could probably make due with 10 or 20 watts per speaker and STILL get evicted. Are the Cary / Lexicon amps the 'same' as ATI or made from different desi gns? |
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Post by rdperry12 on Jan 28, 2017 2:52:59 GMT -5
I was referring to the the GX and ZX 7 model amplifiers from Lexicon. The GX 7 Cary audio 7.125 and the outlaw 7125 as well as the JBL ava 7 are all the same amplifiers made by ATI.
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Post by Casey Leedom on Jan 28, 2017 12:34:51 GMT -5
H power supplies will have 2 or more power rails at different voltages. maybe 15v, 30v and 45v. or just 2 rails. iBias sounds like a scheme to adjust bias IN TIME to the music. Carver did this (or similar) with his tracking power supply and his earlier 'magnetic field' PS. In either case the PS stored Very Little energy (no huge PS Caps) and turned the PS on/off in time to the music. If iBias works, it'll cut down on how much heat sink you need and the electric bill a full 'A' amp can generate. 2 different things. iBias works on the output transistor bias level while the H power supply makes avaialbe higher voltages instantly on demand. I'm a little leery of anything that even feels like MORE FEEDBACK, which the iBias certainly has. I may look up a measurement oriented review to see how it does and if you really can have a class 'A' amp that doesn't weigh a ton and come with enought heatsink to cool a house. So I see various comments with some people arguing in one way or the other regarding "feedback". I'm a little confused about this because I work in systems where Control Theory is used to stabilize Dynamic Systems and, generally speaking, viewed Very Favorably. And integral component of Control Theory is the use of Feedback to measure a System's actual operational performance and feed that back into the Control of the system. So why would the "FEEDBACK" you're talking about be a Bad Thing™? Or are we talking about different definitions of "feedback"? Casey |
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Post by leonski on Jan 28, 2017 14:21:51 GMT -5
Feedback or more properly in an Audio Application Negative Feedback, is another 3rd rail topic. passlabs.com/press/audio-distortion-and-feedbackHere is an article from Pass Labs which might help straighten things out. A little! The article should talk about the 2 main uses of NFB in audio gear. Global feedback is from output BACK to input. The other main type is from stage-to-stage of an amp where each STAGE has its own feedback loop. I worked in an industry which had very precisely controlled furances for the manufacture of semiconductors. One thing I DID notice is that feedback control circuits ALL introduce a form of Overshoot / Ringing. I saw that in both Tempreture control AND gas flow control using Mass Flow Controllers of very high accuracy. |
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