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Post by jamscape on Mar 11, 2013 21:47:41 GMT -5
I've been away for work for the last week and a half and I come back to all this XPA-1L goodness!
Everything about these just seems right for me. I've always wanted mono's but the previous offerings left me with Goldie Locks syndrome. This one is too big, this one is too small, this one is too expensive :-)
These seem to really hit a sweet spot for me. My questions is, do you think these will be a good match with Magnepan 1.6s and are they worth the upgrade from an XPA-2? Maggies are known to perform their best with high current amps and I don't see any specs regarding the max current rating of the 1L. I do see that the wattage doubles from eight to four ohms and this is usually a sign of a high current design. Also, does the 35 watt class A rating also apply to 4 ohms? The specs page only list the class A watts for 8 ohms. My plan would be to always run the amp in the class A mode.
Thanks, Joe
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stiehl11
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Post by stiehl11 on Mar 11, 2013 21:50:39 GMT -5
^Yes, Lonnie said in an earlier post that it's 35 watts at 4 and 8 ohm.
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Post by lynxo on Mar 11, 2013 21:51:49 GMT -5
So what is the Class A output power into a 4 ohm load? The specs only mention for 8ohms.
I think the only reason to compare between the XPA-1 and XPA-1L is if you have power hungry speakers like the Maggies,etc... 30W Class A amp should be able to drive almost every other speaker.
I did at one time greatly enjoyed a pair of the XPA-1 driving my Maggie 1.6's. It truly brought out the Maggie Magic. Unfortunately things happened and they were sold. I later down graded to a pair of UPA-1 monoblocks. The magic is not there. Sold the UPA-1's.
I'm still itching to get another pair of XPA-1's. It's the mass weight of these 2 beasts that hold me back. I really wish the XPA-1 was a 2 chassis design allowing easier logistics. Split the power and amps in 2 chassis.
As Lonnie mentioned, the XPA-1L being half of the XPA-1. My curiosity still lies in if it is possible to get the Maggie magic with the XPA-1L. The smaller size is sweet but at loss of sound quality?
What I like about the XPA-1 is it allows you to listen at low level volumes with the Maggies and still get the tight bass, wide sound stage and everything else this combo has to offer.
Price wise, the XPA-1 is still an amazing deal when on sale.
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stiehl11
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Post by stiehl11 on Mar 11, 2013 22:06:21 GMT -5
So what is the Class A output power into a 4 ohm load? The specs only mention for 8ohms. I think the only reason to compare between the XPA-1 and XPA-1L is if you have power hungry speakers like the Maggies,etc... 30W Class A amp should be able to drive almost every other speaker. I did at one time greatly enjoyed a pair of the XPA-1 driving my Maggie 1.6's. It truly brought out the Maggie Magic. Unfortunately things happened and they were sold. I later down graded to a pair of UPA-1 monoblocks. The magic is not there. Sold the UPA-1's. I'm still itching to get another pair of XPA-1's. It's the mass weight of these 2 beasts that hold me back. I really wish the XPA-1 was a 2 chassis design allowing easier logistics. Split the power and amps in 2 chassis. As Lonnie mentioned, the XPA-1L being half of the XPA-1. My curiosity still lies in if it is possible to get the Maggie magic with the XPA-1L. The smaller size is sweet but at loss of sound quality? What I like about the XPA-1 is it allows you to listen at low level volumes with the Maggies and still get the tight bass, wide sound stage and everything else this combo has to offer. Price wise, the XPA-1 is still an amazing deal when on sale. I didn't see a reply to it so sorry if I missed it but did we find out if Class A power is any higher at 4 ohm or is it the same regardless of 4 or 8 ohm (class A)? Lonnie replied to my email on this. He said the XPA-1L produces it's first 35 watts in pure class A into a eight or four ohm load. No difference. ...
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Post by deltadube on Mar 11, 2013 23:39:25 GMT -5
So what is the Class A output power into a 4 ohm load? The specs only mention for 8ohms. I think the only reason to compare between the XPA-1 and XPA-1L is if you have power hungry speakers like the Maggies,etc... 30W Class A amp should be able to drive almost every other speaker. I did at one time greatly enjoyed a pair of the XPA-1 driving my Maggie 1.6's. It truly brought out the Maggie Magic. Unfortunately things happened and they were sold. I later down graded to a pair of UPA-1 monoblocks. The magic is not there. Sold the UPA-1's. I'm still itching to get another pair of XPA-1's. It's the mass weight of these 2 beasts that hold me back. I really wish the XPA-1 was a 2 chassis design allowing easier logistics. Split the power and amps in 2 chassis. As Lonnie mentioned, the XPA-1L being half of the XPA-1. My curiosity still lies in if it is possible to get the Maggie magic with the XPA-1L. The smaller size is sweet but at loss of sound quality? What I like about the XPA-1 is it allows you to listen at low level volumes with the Maggies and still get the tight bass, wide sound stage and everything else this combo has to offer. Price wise, the XPA-1 is still an amazing deal when on sale. Hey good news for you the xpa 1 is on SALE cheers..
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Post by newprometheus on Mar 12, 2013 2:09:03 GMT -5
This looks like a terrific amplifier, so I'm confused as to why Emotiva seems to be going "a bridge too far" by trying to bill this as a Class A amplifier, when by their own description it is not, but rather a high bias Class A/B amplifier.
To wit, Emotiva describes the XPA-1L thusly:
[..]
Nevertheless, Emotiva proceeds to provide details that seem to contradict this claim:
The problem is: this is precisely what a high bias Class A/B amplifier does. To be clear, a Class A amplifier works in Class A up to the full output power of the amplifier.
Just call it a high bias Class A/B amplifier -- and probably a great one at that. This kind of marketing hype is not only uncharacteristic of Emotiva, but it is also entirely unnecessary. --
Now then, the specifications all look tremendous, but with one notable exception: what is the slew rate?
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Post by garbulky on Mar 12, 2013 2:48:46 GMT -5
I don't think they are fooling anybody. They clearly stated 35 watts class a power and when the switch happens. They havent claimed it is a sole class A amplifier. When it does class A, it's pure class A.
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hemster
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Post by hemster on Mar 12, 2013 2:58:08 GMT -5
35 Watts may not seem a lot but in the Class A configuration it is substantial!
Although Class-A is very desirable as a purist, it is not suitable for high power systems unless ridiculous power dissipation is acceptable (e.g. between 800 to 1500 Watts of pure heat, in order to get ~250-300 Watts of audio). The output devices are ON all the time (i.e. throughout the entire waveform at 360o. However, it can be used for the high frequency amplifier in a bi-amplified system. Then it is feasible to reach high output without needing a dedicated air-conditioning system to dissipate the heat generated.
In the frequency range of 3 kHz and above, relatively little power is needed, and the sonic benefits should be readily apparent - crystal clean highs, without any harsh distortion components. The distortion generated may be (but is not necessarily) predominantly 2nd harmonic, and will be greatest at high power levels where it is least likely to be audible. This is where slew rate is relevant. Class-A amps generally have a high slew rate resulting from the high saturation current involved in the initial stage prior to frequency compensation.
So in summary, Class-A is an amplification mode that requires high current and consequently has higher quiescent (no signal) power dissipation (based on a nominal 24 Volt supply (+/- 12 Volts)). Such amplifiers at very best have an efficiency of less than 30% at full power - at worst, maybe 15% or less.
This amp can stay the distance for up to 35W for the whole frequency range and that is quite amazing IMHO.
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Post by audiohead on Mar 12, 2013 5:06:51 GMT -5
Anyone know what the "slew rate" is?.. newprometheus,very good point bro!Stay around, you made some very good points about this.What gear do you have?You seem too know a lot about amps.But I have too agree with "hemster" on his statement about "slew rate" His is Spot on!
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jlmac
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Post by jlmac on Mar 12, 2013 7:41:54 GMT -5
Lynxo: As Lonnie mentioned, the XPA-1L being half of the XPA-1. If the XPA-1L is half of the XPA-1, is it safe to approximate that the XPA-1 runs the first 16-17 watts in class A before changing to A/B? (I have not read anything on Emotiva's website that certifies how many class A watts the XPA-1 runs in before changing to class A/B.)
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bootman
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Post by bootman on Mar 12, 2013 7:44:06 GMT -5
Lynxo: As Lonnie mentioned, the XPA-1L being half of the XPA-1. If the XPA-1 is half of the XPA-1L, is it safe to approximate that the XPA-1 runs the first 16-17 watts in class A before changing to A/B? (I have not read anything on Emotiva's website that certifies how many class A watts the XPA-1 runs in before changing to class A/B.) No, only the first ten watts. Not on website but mentioned here in the forums. (2nd post in this thread)
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Post by ocezam on Mar 12, 2013 7:47:05 GMT -5
This looks like a terrific amplifier, so I'm confused as to why Emotiva seems to be going "a bridge too far" by trying to bill this as a Class A amplifier, when by their own description it is not, but rather a high bias Class A/B amplifier.To wit, Emotiva describes the XPA-1L thusly:
Jeez, really?! Emotiva is just about the most transparent company I know of. You are really splitting hairs here. To wit: "In Class A/B Mode, the XPA-1L is a potent, superb sounding, fully balanced mono-block Class A/B amplifier – delivering 250 watts into 8 ohms (or 500 watts into 4 ohms) with incredibly low levels of noise and distortion. Flip the switch into Class A Mode and the XPA-1L transforms into pure Class A, high bias 35 watt sweetheart... with a kick. If you exceed the 35 watt threshold, it seamlessly transitions into Class A/B mode when the signal level goes above 35 watts, allowing it to delivering its full power. You get the awesome purity of Class A for power levels up to 35 watts, with none of the high power limitations. (The XPA-1L does run a bit warmer in Class A Mode, but hey, it worth it.)"How could they be more clear than that? To imply they have to lump this in with other, "normal", class AB amps is silly. Very few amps (all of them priced 5 to 10 times higher) will do what the XPA-1L will do.
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reaper60
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Post by reaper60 on Mar 12, 2013 8:11:15 GMT -5
Agreed, a high bias class A/B amp will not give you the option of running the 35 watts of class A before switching. It will just be built in to run that way. To me it means runner hotter all the time. If it's 95 degree's here in the summer and my electric bill is already sky high, I like having the option to throw the switch to a standard A/B amplifier with far less class A and subsequently, heat! I also tend to be different from the rest in this forum in that my main system is primarily a theater. I am 70% movies, games, TV, and onlye 30% music as I have a 2 channel tube system for the music only. While the XPA-1L certainly has a juicy appeal, I will stick with my XPA-1's for now as I enjoy them very much and can't see spending the money to replace them with half power for more heat and class A.
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Post by Jim on Mar 12, 2013 8:43:56 GMT -5
The problem is: this is precisely what a high bias Class A/B amplifier does. To be clear, a Class A amplifier works in Class A up to the full output power of the amplifier. Just call it a high bias Class A/B amplifier -- and probably a great one at that. This kind of marketing hype is not only uncharacteristic of Emotiva, but it is also entirely unnecessary. So you'd rather have a class A amp that starts clipping above 35W? OK then.... I'm sure Emotiva could build one, but whats the point? A space heater with limited output. If you really think that class A is the be-all-end-all, just figure out where the 35W level is and stick below it. I wouldn't call it hype. I'd call it flexibility. It's like a car. Want good gas milage? Stay at a reasonable speed. Want to punch it? No problem, your fuel consumption will just go up. I'd LOVE to see someone prove in a double blind test that they could hear the difference between A and A/B peaks.
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Post by laserman35 on Mar 12, 2013 9:43:52 GMT -5
I do not know if i could hear a difference in between class A or A/B.
But i like it, I think i might sell my XPA-5 and replace it with 2-3 of these.
Was $699 the sale price, I would be more interested in this upgrade at $599.
I know it's the best value in the market today. I'm going to think allot about this before making this upgrade. I have a problem with upgrades unless there is a significant difference.
With my XMC-1 upgrade coming soon i might just pull the trigger and get a few of these.
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KeithL
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Post by KeithL on Mar 12, 2013 10:12:47 GMT -5
Slew rate is one of those often-misunderstood measurements. The ONLY reason slew rate matters is because, if it is insufficient, it will cause certain distortions (especially in amps with feedback). We may get around to measuring the slew rate in the XPA-1L or not but, IF IT WASN'T GOOD ENOUGH, that fact would show up in the frequency response and distortion figures. The amazingly good distortion figures for the XPA-1L prove that its slew rate is quite adequate Anyone know what the "slew rate" is?.. newprometheus,very good point bro!Stay around, you made some very good points about this.What gear do you have?You seem too know a lot about amps.But I have too agree with "hemster" on his statement about "slew rate" His is Spot on!
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Post by KeithL on Mar 12, 2013 10:25:05 GMT -5
No. All Class A/B amps run in Class A mode for some few watts (or a fraction of a watt) at very low power levels. This is what distinguishes Class A/B amps from Class B, and why they sound better. The XPA-1L is designed specifically so that, when it is in Class A mode, it will be running in Class A up to levels where most people listen to music most of the time. In Class A/B Mode, the XPA-1L is comparable to the XPA-1 (although at half the power). The XPA-1 is a Class A/B ONLY amp, doesn't have a Class A switch, and does not run in Class A mode to sufficient levels that you can expect to be listening to it in Class A very much of the time. (Of course, it sounds superb in Class A/B.) The actual number of watts which the XPA-1 delivers in Class A depends on how warm it is, and several other factors, and so we don't specify it precisely. Article #1 of the EmoZine will cover this in more detail (look for it by the end of the week). emotivalounge.proboards.com/index.cgi?board=magazineLynxo: As Lonnie mentioned, the XPA-1L being half of the XPA-1. If the XPA-1L is half of the XPA-1, is it safe to approximate that the XPA-1 runs the first 16-17 watts in class A before changing to A/B? (I have not read anything on Emotiva's website that certifies how many class A watts the XPA-1 runs in before changing to class A/B.)
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Post by KeithL on Mar 12, 2013 10:27:45 GMT -5
The XPA-1L is indeed a high-current amp, is totally stable into low-impedance loads, and will just LOVE Magneplanars I've been away for work for the last week and a half and I come back to all this XPA-1L goodness! Everything about these just seems right for me. I've always wanted mono's but the previous offerings left me with Goldie Locks syndrome. This one is too big, this one is too small, this one is too expensive :-) These seem to really hit a sweet spot for me. My questions is, do you think these will be a good match with Magnepan 1.6s and are they worth the upgrade from an XPA-2? Maggies are known to perform their best with high current amps and I don't see any specs regarding the max current rating of the 1L. I do see that the wattage doubles from eight to four ohms and this is usually a sign of a high current design. Also, does the 35 watt class A rating also apply to 4 ohms? The specs page only list the class A watts for 8 ohms. My plan would be to always run the amp in the class A mode. Thanks, Joe
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Post by Jim on Mar 12, 2013 11:20:52 GMT -5
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Post by newprometheus on Mar 12, 2013 11:37:47 GMT -5
I don't think they are fooling anybody. Let me be clear: I am a big fan of Emotiva, so I don't think they are trying to fool anyone, but I am a vigilant advocate for intellectual honesty. My apologies in advance, as I do not intend to be argumentative but I think I have a valid point. They clearly stated 35 watts class a power and when the switch happens. They havent claimed it is a sole class A amplifier. When it does class A, it's pure class A. The product description for the XPA-1L indicates that it features "selectable Class A and Class A/B mode switching", but it does nothing of the sort. Instead, it should be described as featuring "selectable bias switching". After all, when "switched" to Class A mode, the XPA-1L does not "transform into pure Class A" amplifier (as described), since by definition, a pure Class A amplifier works in Class A mode up to the full output power of the amplifier. Instead, switching to "Class A mode" on the XPA-1L only adjusts the bias so that it operates in Class A mode for an increased portion of the full output power of this superb Class A/B amplifier.
On a lighter note...
my main system is primarily a theater.
LOL: I originally read this as "my main system is primarily a heater"
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