XPA-1 vs XPA-2

[michaelg523]

Hi!

I´ve got a XPA-2 (gen 1) since a couple of years with which I´m very pleased. Recently I got myself a new pair of speakers (Revel Studio2) which are less effective than my old ones, but on the other hand they can handle more power. Therefore the XPR-2 seems to be the natural choise. Unfortunately these don´t ship to Europe. And that´s why I´m posting here.


When I read about XPA-1 and take a closer look at specs and measurements, it seems to me as if it beside twice the power (per chanel compared to XPA-2) - also has got considerably lower distortion. And this is what my questions are about. Have I read the specs/measurements correctly? And if so - is the lower grade of distortion audible? (Or more correctly - is the higher grade of distortion of XPA-2 audible?)

Kind regards, Michael

Ps. English isn´t my native laguage. Hopefully You´ll understand what I´m trying to say anyway.

[jackpine]

None of the amps will have audible distortion at their rated outputs. An amp with a better spec might play just higher above the rating before it distorts. You would have to look at the graphs to confirm this though. The main benefit of the XPA-1 pair over the XPR-2 would be the benefit of having mono blocks. You also get the ability to run them in Class A up to sixty watts which some people prefer the sound of.

[garbulky]

I can't tell if you'll hear this difference. But...the XPA-1 is fully balanced unlike the XPA-2. Which means a reduction in a certain type of distortion. Also the class A watts may be beneficial. Now will it sound better? I don't know. I never heard it. But I did hear the XPR-2 and an XPA-2. They sound slightly different. Both benefit from an XSP-1 pre-amp driving them (imo).

[tchaik]

Jul 7, 2015 19:01:56 GMT -5 garbulky said:

I can't tell if you'll hear this difference. But...the XPA-1 is fully balanced unlike the XPA-2. Which means a reduction in a certain type of distortion. Also the class A watts may be beneficial. Now will it sound better? I don't know. I never heard it. But I did hear the XPR-2 and an XPA-2. They sound slightly different. Both benefit from an XSP-1 pre-amp driving them (imo).

in my conversation with lonnie at the last emofest, he felt the XPA-1's were better sounding, more refined yet just as powerful as the XPR-2 and definitely more refined and more powerful than the XPA-2. the differential reference design and 60 watts class A were the key ingredients in his mind.



tchaik……………..

[Gary Cook]

Perhaps it might help if we knew what else is in your system and what's the room like acoustically? Maybe there are more effective things to spend your money on.

Cheers
Gary

[michaelg523]

Thank You all for Your input!

jackpine; What is the benefit of having mono blocks? Or is it just a matter of preferenses which is more practical? The benefit of class A would be even lesser distortion, but according to the measurements I´ve seen, there is a bigger difference in distortion between XPA-1 and XPA-2 than there is between class A and class A/B in XPA-1. Or is it about different kind of distortions? (I don´t know - just speculating...)

garbulky; The difference in sound between XPA-2 and XPR-2, was it audible within respective amps working area?

tchaik; This indicates perhaps lesser audible distortion in class A.

Gary Cook; My main sound sorces are an Arcam CD-player, a PC with HDMI and a Thorens TD166 turnable with Goldring pu. All my interconnects are RG62 with good connections (just feelgood - I don´t really hear any difference compared to original interconnects . A Denon X4000 receiver acts pre in music listening and takes care of the surround channels in movies. Emotiva XPA-2 feeds my main speakers (Revel Studio2) and are connected with 10 meters of 5mm2 (about 10 AWG) electrical wire. A SVS PB12/2 subwoofer takes care of the lowest octave i movies and music. (So I ended up with three americans; Emotiva, Revel and SVS!) The room is about 23 square meters (about 250 ft2) with a carpet on the floor and drapery on about 1/3 of the walls. On the rest of the wall there are bookshelves etc. I´ve tried to avoid empty parallell spots. The sofa is about a meter in the room (with a Bookshelf along the entire back wall).

Just for the record; I know how hard it can be to really hear any differenses sometimes. And I know how easy it can be to hear large differenses where really aren´t any.

Michael

[garbulky]

It was in the sound signature and it was rather subtle. Depending on your setup you may not hear any difference. The XPR-2 sounded similar to the old UPA-2 (or current XPA-200). However it was better than the UPA-2...just a similar sound signature. It was a laid back relaxed sound. A slightly laid back or diminished treble. There was a bit better 3 dimensional body - maybe because of the treble signature, maybe not. The power being delivered was delivered in a relaxed way.
Compared to the XPA-2, the XPA-2 had a bit more in common with the rest of the XPA series sound signature at least in spirit.
The XPA-2 however had a really nice "speed" to things versus the UPA-2 I had.
Directly compared to the XPR-2, the difference was the sound signature I mentioned.

The XPA-2 btw shares a good bit of similarity with an XPA-1 in terms of design. I believe it is an XPA-1 repurposed to be a stereo amp with some differences.

If you don't have a stereo pre-amp I would reccomend an XSP-1 instead of an amp upgrade for value for money. Both those amps I noticed perked up in terms of dynamics with the XSP-1 versus direct to amps from a processor or DAC.

The monoblocks allow you to have TWO power supplies. One per channel. It also completely cuts out interchannel distortion. Having said that the XPR-2 really has excellent interchannel distortion specs.
Another thing monoblocks allow you to do is to place the amp right next to the speaker. Less wire legnth. Not sure if that makes any difference. The class A of the XPA-1 gen 2 also eliminates a thing called crossover notch distortion when in class A.
This distortion is present in every single wave cycle in class AB but absent in class A.
The first pic is class A. The second is class B (AB).

[Gary Cook]

I agree with garbulky on this one, you have good sources, good amplifier, good speakers and a room that reads as though it should be OK. So for stereo 2.1 music I think the best benefit would come from a quality pre amp, like an XSP-1. Quite a sound quality step up from a processor, especially for vinyl, the XSP-1 phono pre amp is a ripper.


Cheers
Gary

[vcautokid]

As long as all of your components are fully balanced ahead of the amp, you'll really appreciate, the dynamics, better signal to noise, and all the detail that goes with a fully balanced, fully differential system. For example the XSP-1, and the XPA-1 and the ERC-3. These all run this way fully balanced, and fully differential.

[michaelg523]

Thank You for input!



I started this thread of curiosity if the dramatically lower distortion by XPA-1 compared to XPA-2 would give any audible advantages. The answers in this thread and on other places at the Emotiva Lounge seems to stretch from "no significant audible differense" to "XPA-1 sounds clearly better". Well I don´t expect any groundbraking differenses, so i recon I primarily get the double power (+3 dB/channel) and then I maybe will get a perhaps somewhat more high resolution treble.

But then some of You have ideas of a better preamp - XPS-1. Well this isn´t what I was looking for, but I have to admit you´ve made me curious. I am contend with the sound at home. In fact I´ve never heard anything clearly better anywhere, no matter the price. But I´ve heard a lot of sound systems that sounds worse. And in many cases, only the cables costs more than my entirely sound system! Still I hear from audiophils that I never will get a good sound with a Denonreceiver, or a CD-player that doesn´t cost XXX $$, or better power chords, etc. Nevertheless the music sounds better by me, than in most plases. This of course make me somewhat sceptical to putting money in electronics that will give me anytning but raw power.

At the same time I am curious of; can it sound even better? So now I really don´t know what to think. 

[monkumonku]

Throwing in my two cents here... first off, a question: What, if anything, with your present system is not satisfying to you? By this I mean is there anything that bothers you because the sound is not satisfactory (i.e., is anything substandard or below your minimum expectations).

Now assuming your system meets your minimum expectations, what exactly do you want to improve? What's your goal?

You say your new Revel's are "less effective" than the old ones. What do you mean by that, or do you really mean less "efficient."

It seems to me that without knowing the answers to the above, we really can't give you an intelligent answer. Instead, we just answer you based on our own ideas of what you need even though we don't know what that is.

[garbulky]

What is your source? I have found that when a certain resolution level is reached that the source tends to be more important. If you are using a Revel studio 2 and running it off a reciever, I can promise you that you are not driving those speakers to their full potential.

Also if you haven't done so already. You really want room treatments. Even ONE will help. Stick this on the wall behind your couch at head level. Best improvement for your money.
www.atsacoustics.com/item--ATS-Acoustic-Panel-24-x-48-x-2--1001.html

[KeithL]

I have to step in and make a minor correction here.

The picture of the second waveform (with the big crossover notch) would be fair for a Class B amplifier, but NOT for a Class A/B amp.

In a Class B amplifier, there is a slight "time gap" between when one transistor switches off and the other switches on, which creates the flat spot or glitch at the zero crossing. In a Class A/B amplifier, current remains flowing at all times in both transistors, and so neither shuts fully off - so the big notch like in the picture is NOT present in Class A/B amps. In a typical Class A/B amp, there will instead be two points above and below the zero crossing where the current flow in one transistor continues to change while that in the other does not, but the result is a very slight bit of distortion - so slight that it almost certainly won't be visible on an oscilloscope trace.  

The "Class B notch", as shown in the picture, is especially unpleasant because, as you reduce the power level, the overall waveform gets smaller but the notch does not - resulting in distortion that, as a percentage of the overall signal, rises sharply, and becomes very audible at very low power levels. In contrast, the slight nonlinearities caused by Class A/B operation occur mainly away from the zero crossing, and actually disappear altogether when the signal drops to a low enough level that the amp is in its Class A operating range. (An oscilloscope picture of the output of a Class A/B amp looks about the same as the output of a Class A amp; the difference only shows up as a slightly higher amount of THD, and a slightly different distortion spectrum.)

Jul 8, 2015 3:11:46 GMT -5 garbulky said:

It was in the sound signature and it was rather subtle. Depending on your setup you may not hear any difference. The XPR-2 sounded similar to the old UPA-2 (or current XPA-200). However it was better than the UPA-2...just a similar sound signature. It was a laid back relaxed sound. A slightly laid back or diminished treble. There was a bit better 3 dimensional body - maybe because of the treble signature, maybe not. The power being delivered was delivered in a relaxed way.
Compared to the XPA-2, the XPA-2 had a bit more in common with the rest of the XPA series sound signature at least in spirit.
The XPA-2 however had a really nice "speed" to things versus the UPA-2 I had.
Directly compared to the XPR-2, the difference was the sound signature I mentioned.

The XPA-2 btw shares a good bit of similarity with an XPA-1 in terms of design. I believe it is an XPA-1 repurposed to be a stereo amp with some differences.

If you don't have a stereo pre-amp I would reccomend an XSP-1 instead of an amp upgrade for value for money. Both those amps I noticed perked up in terms of dynamics with the XSP-1 versus direct to amps from a processor or DAC.

The monoblocks allow you to have TWO power supplies. One per channel. It also completely cuts out interchannel distortion. Having said that the XPR-2 really has excellent interchannel distortion specs.
Another thing monoblocks allow you to do is to place the amp right next to the speaker. Less wire legnth. Not sure if that makes any difference. The class A of the XPA-1 gen 2 also eliminates a thing called crossover notch distortion when in class A.
This distortion is present in every single wave cycle in class AB but absent in class A.
The first pic is class A. The second is class B (AB).

[michaelg523]

What, if anything, with your present system is not satisfying to you? By this I mean is there anything that bothers you because the sound is not satisfactory (i.e., is anything substandard or below your minimum expectations).

My system sounds really good - among the best I´ve ever heard. Which proves "my" thesis that speakers + room + enough power will do it. The rest is more about scratching the serface. 

Now assuming your system meets your minimum expectations, what exactly do you want to improve? What's your goal?

The ability to play even louder; i.e. more power than XPA-2 can produce. That´s why I consider XPA-1.

You say your new Revel's are "less effective" than the old ones. What do you mean by that, or do you really mean less "efficient."

Yes, I think so. The Revel´s output is about 88 dB/w/m, while my older speakers was about 91 dB/w/m.

It seems to me that without knowing the answers to the above, we really can't give you an intelligent answer. 

English isn´t my native laguage, so I find it rather difficult to express myself adequate. I´m sorry if this makes me somewhat confusing. My first goal is more power. And my initial posting was just abot whether the difference in distortion between XPA-1 and XPA-2 is audible, or not. Just a question - nothing more. But when multiple members of the lounge recommends XPS-1 for better sound, I get curious. Not that I expect anything ground braking, rather a "scrath on the Surface".  But even the right kind of scratch can justify an interest.

Garbulky; My sources are an Arcam CD-player, PC with HDMI, and a Thorens turnable. My Denon receiver is just preamp. I´m driving my Revel´s with a XPA-2. My room is rather well treated with a thick carpet, drapery on the walls near to the speakers, and bookshelves on the rest of the walls. I´ve no problems with standing waves in my listening postition. I´m sitting about 1 meter from the back wall. barely 3 m from the speakers, and yet another meter from the front (speakers-) wall.

[garbulky]

It sounds to me like you are running a two channel setup. I think this would be perfect for the clarity of the XSP-1 vs the Denon. The thick carpet helps a LOT! The drapery helps a little. You likely have reflections in your room. I would still reccomend the ats acoustics. I too have thick carpet and drapery. I was so surprised at how much reflections reduced. I didn't even realize I had reflections. The one I showed you does very little to reduce standing bass waves. It however does reduce reflections in the mid range clearing up the sound significantly. Well worth the $50 bucks!

As for the XPA-2. Your studio is a rather large speaker. However did you know how power requirements change for loudness? For instance at moderate volumes (less than a 100 watts) you can double the volume level easily by upping the amp power. But when you get to the level of power that the XPA-2...twice the power doesn't get close to twice as loud. I think it's really something more like 3 db. When I think it takes 10 db (or was it 6 db) to double the perceieved volume.
Having said that. I'm not saying don't get the very fine XPA-1. It's a fine amp

I just think you may be more satisfied with my other suggestions.

Also if your Arcam CD player is relatively old...say 5 years old...there have been remarkable strides in digital audio reproduction. It doesn't have to make your Arcam CD player obsolete. But you could purchase an external DAC like the very finely reviewed Schiit Ygdrassil (Expensive though) and likely see an improvement by connecting it to the CD player via digital output. The Schiit Ygdrassil is one of the lowest priced multi bit DACs out there along with some other remarkable groundbreaking features that make it unlike other DACs out there.
schiit.com/products/yggdrasil


But for all that you are going to need an XSP-1. Currently with your Denon you are losing the fully balanced signal path as it is not fully balanced - even if it has XLR outputs.

Also you may not know this. I'm more worried about your Denon.
Depending on the Denon, it is likely converting the high quality analog signal of the Arcam (and even the Thorens turntable !!!! ) BACK into digital by the analog to digital converter in the Denon. Then the Denon would reduce the volume digitally from maximum to match the volume level you need by literally chopping bits off. This digital truncation lowers the resolution of the signal when it turns it down thereby lowering quality.
The reason for this is the Denon usually does not have an analog volume control. So all that high quality analog has to be converted TO digital so that it's digital processors can reduce the volume using a digital volume control.
So here resolution loss is found both by the analog to digital conversion. But also the digital volume control chopping bits.

After it does that.... the DAC in the Denon will then reconvert the digital signal back into analog using its onboard DAC. So here resolution loss occurs and whatever you paid for your Thorens turntable can be somewhat limited because it can only sound as good as the DAC in the Denon.

I say this because the XSP-1 can completely do away with all those resolution lowing conversions ....plus offer a fully balanced signal path for your upcoming XPA-1 both of which the Denon lacks. Hope this stuff helps. I think your Revels look like amazing speakers. You must have a lot of fun listening to them. Do you have any pictures?

[jackpine]

Your new speakers are 3Db less efficient doubling your amplifier power will give 3Db more volume. This will get you back to approximately where you were before volume wise. It's an improvement but not a big one for the money spent. A high quality stereo pre-amp like the XSP-1 will likely give you a bigger improvement in two channel listening. Think of it this way 80% of the circuitry in your Denon is for all sorts of features and multi channel, not specifically for 2 channel sound. If you want louder, better control of the bass ect. get the bigger amps. If you want a deeper soundstage, better separation of instruments and voices, finer low level detail get a high quality stereo pre-amp.

[garbulky]

I just read my wall of text. My apologies! Long story short. It's possible your Denon will convert the nice analog signal to digital thereby limiting the quality of your turntable and CD player by the digital circuitry in the Denon. Hence my reccomendation of the all analog XSP-1.

[monkumonku]

You must like to play your stuff loud! Personally, within their intended usage I don't think you would hear any difference in sound between the XPA-2 and XPA-1 - you are not going to hear audible distortion as long as they are operating within their intended ranges. The XPA-1 has more headroom so if it is power you want and you are unable to get the XPR series because of being overseas, then the XPA-1 would be the next best thing. I think you will benefit from getting a dedicated preamp like the XSP-1. As others have pointed out, the Denon is more like a jack of all trades which means stuffing a lot of circuitry into the box that doesn't have as specialized a use as would be an XSP-1.

But as far as hearing distortion, if you operate the XPA-2 at or below 300 watts into 8 ohms and the XPA-1 at or below 500 watts, then you are not going to hear any distortion and my two cents is you won't be able to tell which amp is which in a blind test. It is only if you need the extra headroom that the XPA-1 gives you, that you will hear a difference.

[novisnick]

Jul 9, 2015 9:19:40 GMT -5 monkumonku said:

You must like to play your stuff loud! Personally, within their intended usage I don't think you would hear any difference in sound between the XPA-2 and XPA-1 - you are not going to hear audible distortion as long as they are operating within their intended ranges. The XPA-1 has more headroom so if it is power you want and you are unable to get the XPR series because of being overseas, then the XPA-1 would be the next best thing. I think you will benefit from getting a dedicated preamp like the XSP-1. As others have pointed out, the Denon is more like a jack of all trades which means stuffing a lot of circuitry into the box that doesn't have as specialized a use as would be an XSP-1.

But as far as hearing distortion, if you operate the XPA-2 at or below 300 watts into 8 ohms and the XPA-1 at or below 500 watts, then you are not going to hear any distortion and my two cents is you won't be able to tell which amp is which in a blind test. It is only if you need the extra headroom that the XPA-1 gives you, that you will hear a difference.

Well written and very well thought out! Yes, a preamp, I love the XSP-1, will raise the quality of the music about 10 fold.
well,,,,,,,,,,,,,,almost!! 

[monkumonku]

Jul 9, 2015 9:54:14 GMT -5 novisnick said:

Jul 9, 2015 9:19:40 GMT -5 monkumonku said:

You must like to play your stuff loud! Personally, within their intended usage I don't think you would hear any difference in sound between the XPA-2 and XPA-1 - you are not going to hear audible distortion as long as they are operating within their intended ranges. The XPA-1 has more headroom so if it is power you want and you are unable to get the XPR series because of being overseas, then the XPA-1 would be the next best thing. I think you will benefit from getting a dedicated preamp like the XSP-1. As others have pointed out, the Denon is more like a jack of all trades which means stuffing a lot of circuitry into the box that doesn't have as specialized a use as would be an XSP-1.

But as far as hearing distortion, if you operate the XPA-2 at or below 300 watts into 8 ohms and the XPA-1 at or below 500 watts, then you are not going to hear any distortion and my two cents is you won't be able to tell which amp is which in a blind test. It is only if you need the extra headroom that the XPA-1 gives you, that you will hear a difference.

Well written and very well thought out! Yes, a preamp, I love the XSP-1, will raise the quality of the music about 10 fold.
well,,,,,,,,,,,,,,almost!! 

I'm surprised you didn't contend with my remark about the XPA-1 and XPA-2 sounding the same. What kind of monoblock CEO are you, anyway???