Check out Emotiva's new XPA-1L Class A/AB Amp!

[admin]

Emotiva's new XPA-1L has selectable Class A/Class A/B operation! Do you think they'll implement this Class A switch to their entire line?

Discuss "Emotiva Audio XPA-1L Class A Amplifier Preview" here. Read the article.

 

[3db]

Not bad for the money. The idea of an amp that switches from class A to class A/B has been around for eons but not at that price point. I don't understand why it took so long for a company like Emotiva to toss one out into the park at prices most of us could easily afford.

 

[slipperybidness]

I dunno....it seems too much like a gimmick to me

 

[jinjuku]

I dunno....it seems too much like a gimmick to me

If they have an audibly transparent switch that adjusts the biasing level I don't see why it would be a gimmick.

 

[Irvrobinson]

If they have an audibly transparent switch that adjusts the biasing level I don't see why it would be a gimmick.

I was all ready to disagree with slipperybidness too, but after thinking about it I have to agree with him. If you want a Class A amp just get one; switching back and forth is something you'll probably do on the first day you get the amp and never do it again. Unless you choose the Class A mode and then find you're running into clipping later.

I'm also not liking that recommendation from Emotiva to avoid speakers that fall below 4 ohms. A lot of great speakers fall below four ohms in some part of their bandpass, and it seems to me those are some of the most likely speakers to benefit from Class A operation.

 

[jinjuku]

I would rather have the flexibility than not. To each their own.

 

[j_garcia]

My PM7200 does this as well (the reason I bought it) and you really can't tell that it is doing anything. Sounds great in class A, as it can be configured for A - A/B switching or pure class A; though in pure class A it gets really hot after a while It is 25W in class A and 95W in A/B.

 

[Steve81]

I'm also not liking that recommendation from Emotiva to avoid speakers that fall below 4 ohms. A lot of great speakers fall below four ohms in some part of their bandpass, and it seems to me those are some of the most likely speakers to benefit from Class A operation.

I'm a little curious where that came from; there is a note in the XPA-1L's manual that the minimum recommended load impedance is 4 ohms, but that same note is in the XPR-1's manual as well.

 

[ocezam]

I dunno....it seems too much like a gimmick to me

I was all ready to disagree with slipperybidness too, but after thinking about it I have to agree with him. If you want a Class A amp just get one; switching back and forth is something you'll probably do on the first day you get the amp and never do it again. Unless you choose the Class A mode and then find you're running into clipping later.

Yeah it's a gimmick. Just like these gimicky amps:

https://passlabs.com/products/amplifiers/x.5

I'm a little curious where that came from; there is a note in the XPA-1L's manual that the minimum recommended load impedance is 4 ohms, but that same note is in the XPR-1's manual as well.

I'm curious also. Emotiva never rates their amps into less than a 4 ohm (nominal) load. The key word here is nominal. There are reports of them being stable to two ohms, it's just not rated.

 

[ocezam]

I bought a pair of these. They'll be here Friday.

Independent test results put actual power at:

At 8 ohms with a 1Khz sine wave:
XPA-1L; 363 watts

At 4 ohms with a 1Khz sine wave:
XPA-1L; 553 watts

I think these will prove to be some killer mono blocks!

 

[Irvrobinson]

Yeah it's a gimmick. Just like these gimicky amps:

https://passlabs.com/products/amplifiers/x.5

How are Pass Labs amps gimmicky? I think their circuitry is pretty cool.

 

[Mopkins]

Nice work guys! I'm interested in taking a listen and I already know someone who I'll recommend taking a look as he's in the market for class A..4ohm may be an issue though...

 

[gene]

Guys; realize the amp has differential outputs which bridges two-channels together. Each side of the amp sees 1/2 the load impedance so that is why they likely rate it for 4 ohms. It will work with 4 ohm speakers fine but won't be able to double down into a 2 ohm load due to current limitations. I'm running XPR-1s on my Status speakers that dip down to 2 ohms at bass frequencies, and they don't even break a sweat!

 

[internetmin]

Class A Emotiva or higher power Monoblock?

Guys, I'm not the engineer so I have a question about the XPA-1L. If you were to compare (on paper at this point) the XPA-1, the XP-1L, and the XPR-1, which one in theory would sound better and why?

Is it ultimately more power that makes the difference? Is it the Class A that makes the difference?

d

 

[j_garcia]

Guys, I'm not the engineer so I have a question about the XPA-1L. If you were to compare (on paper at this point) the XPA-1, the XP-1L, and the XPR-1, which one in theory would sound better and why?

Is it ultimately more power that makes the difference? Is it the Class A that makes the difference?

d

There is an entire thread on that here: http://forums.audioholics.com/forums/amps-pre-pros-receivers/84632-can-you-hear-difference-sound-between-audio-amplifiers.html

 

[internetmin]

There is an entire thread on that here: http://forums.audioholics.com/forums/amps-pre-pros-receivers/84632-can-you-hear-difference-sound-between-audio-amplifiers.html

Thanks J. I had previously read the article; however my question is not so much whether or not they sound different in a theoretical sense but from an engineering POV when you pit Class A at X watts/channel vs Class A/B at Y watts/channel (x being < Y) then what are you gaining or losing between the two in sound difference. I'm talking about two amps that are using different kinds of amplification and also different wattage and that's where my question lies; it's not in having Amp 1 vs Amp 2 at the same wattage and class and telling the difference. That's the essence of what I'm asking and asking it from an engineering POV.

 

[j_garcia]

I referenced that thread because there is a lot of discussion about why some amps sound different - more regarding the design and characteristics, not so much the wattage.

Wattage alone will not account for a difference in sound unless there wasn't enough of it. I guess I see it like this: you need 100W unclipped to achieve your desired listening level. A 500W amp won't suddenly make things sound like a million dollars compared to a capable 200W amp. BOTH of those amps will be an improvement over a 50W amp that struggles to achieve that 100W unclipped.

My PM7200 in class A sounds basically smooth and clean, like looking at something through a window vs opening the window. Not totally different, but more clear I guess?

 

[gene]

Thanks J. I had previously read the article; however my question is not so much whether or not they sound different in a theoretical sense but from an engineering POV when you pit Class A at X watts/channel vs Class A/B at Y watts/channel (x being < Y) then what are you gaining or losing between the two in sound difference. I'm talking about two amps that are using different kinds of amplification and also different wattage and that's where my question lies; it's not in having Amp 1 vs Amp 2 at the same wattage and class and telling the difference. That's the essence of what I'm asking and asking it from an engineering POV.

At low listening levels, possibly. At higher listening levels, always go with the more powerful amp, all other things being equal.

 

[internetmin]

At low listening levels, possibly. At higher listening levels, always go with the more powerful amp, all other things being equal.

Thanks Gene... and in theory that would be because of greater dynamics and greater control of the speakers with the more powerful amp?

 

[internetmin]

I referenced that thread because there is a lot of discussion about why some amps sound different - more regarding the design and characteristics, not so much the wattage.

Wattage alone will not account for a difference in sound unless there wasn't enough of it. I guess I see it like this: you need 100W unclipped to achieve your desired listening level. A 500W amp won't suddenly make things sound like a million dollars compared to a capable 200W amp. BOTH of those amps will be an improvement over a 50W amp that struggles to achieve that 100W unclipped.

My PM7200 in class A sounds basically smooth and clean, like looking at something through a window vs opening the window. Not totally different, but more clear I guess?

First, I forgot to mention how I laughed when I saw your tag, "Seriously, I have no life." Hysterical.

Secondly, in your case, you do notice a difference with class A mode on the Marantz amp.

One of my friends who's not an electrical engineer but an engineer nonetheless basically said that the class A would yield a "better" (smoother, more accurate, etc) sound because of the purer wave in class A mode. However, he was also saying that if the speakers are really power hungry then having an amp with as much wattage as possible would exhibit more control and refinement.

I'm not the engineer but I just don't like going by audiophile folklore. I want to understand a bit of the science behind it as much as possible. Simple statements just don't do it for me.