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Post by jackfish on Apr 4, 2010 10:52:30 GMT -5
I'm a little unsure about the roles large toroidal transformers and high secondary capacitance play in amplifier performance. The Emotiva UPA-1 monoblock is rated at 200 watts into 8 Ohms and 350 watts into 4 Ohms and has a 300VA toroidal transformer and 80,000uF secondary capacitance (600VA and 160,000uF stereo equivalent in a pair), while the Emotiva XPA-2 stereo amplifier is rated at 300 wpc into 8 Ohms and 500 wpc into 4 Ohms and has 1,200VA toroidal transformer and 45,000uF secondary capacitance. It appears the XPA-2 delivers its noted "slam" due to the front end power of its large transformer (twice as large as the UPA-1 pair) and hence needs less capacitive power for peaks and transients, while the UPA-1 will have a bit less up front "slam" with half the transformer voltage but will easily handle peaks and transients with almost 4 times the capacitive power. Does this adequately explain the differences between these two amps or is there more detail or clarity someone could add?
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DYohn
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Post by DYohn on Apr 4, 2010 11:12:19 GMT -5
I'm a little unsure about the roles large toroidal transformers and high secondary capacitance play in amplifier performance. The Emotiva UPA-1 monoblock is rated at 200 watts into 8 Ohms and 350 watts into 4 Ohms and has a 300VA toroidal transformer and 80,000uF secondary capacitance (600VA and 160,000uF stereo equivalent in a pair), while the Emotiva XPA-2 stereo amplifier is rated at 300 wpc into 8 Ohms and 500 wpc into 4 Ohms and has 1,200VA toroidal transformer and 45,000uF secondary capacitance. It appears the XPA-2 delivers its noted "slam" due to the front end power of its large transformer (twice as large as the UPA-1 pair) and hence needs less capacitive power for peaks and transients, while the UPA-1 will have a bit less up front "slam" with half the transformer voltage but will easily handle peaks and transients with almost 4 times the capacitive power. Does this adequately explain the differences between these two amps or is there more detail or clarity someone could add? Close, but, not quite. In general the way a linear power amplifier works is the output stages draw their current from the capacitive bank, and the caps draw their power from the transformer. The voltage remains relatively stable with a properly designed power supply. So in theory, a larger capacitive bank means the output stage has more current "on tap" to draw from, and the transformer is sized to recharge the caps. There is a point of diminishing returns where creating a larger power supply has very little to no effect on the amp's performance because the output stages are only capable of so much. Most commercial amplifier designs are optimized for the best trade-off between a large enough power supply to provide the current the output stage requires and a the smallest possible power supply to minimize manufacturing costs.
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cgolf
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Post by cgolf on Apr 4, 2010 14:46:48 GMT -5
Just bought a pair of UPA-1s to compare against my XPA-2. Reviews, thoughts and results coming next weekend.......... ;D
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hemster
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Post by hemster on Apr 4, 2010 14:51:44 GMT -5
Just bought a pair of UPA-1s to compare against my XPA-2. Reviews, thoughts and results coming next weekend.......... ;D I'm eagerly awaiting this feedback. Can't wait. Happy listening!
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Post by orangeLollies on Apr 7, 2010 16:20:26 GMT -5
Damn it guys!!!! ...now I'm havin dreams about doing blind comparisons between XPA-2 and 2xUPA-1s ....The XPA-2 won btw, a lot cleaner, dynamic, contrast...etc, whereas the UPAs were all muddy and compressed...That'll be Lonnies fault for using the 'laid-back' term. For those who missed it, the above statement was based on a dream, not reality - so don't start slamming me, asking how I came to this conclusion and how my tests were conducted ;D Only a few days ago, I was contemplating an actively bi-amped XPA-5 over an XPA-2, I decided to stick with the XPA-2. Now ya got me thinking about UPA-1s. It's tough, cos on one hand I like to listen to the likes of Nora Jones nice n quiet. And on the other hand I like to listen to Dream Theater, Porcupine Tree, Opeth, Tool at rock concert levels. ;D Starting to think this indecision is a bit like standing in a queue at the supermarket. We all know what happens when ya change queue's in the supermarket aye... You end up regretting it, as you watch the queue you 'were' in suddenly speed through... It's a hard life. Look forward to reading some more comparison reviews.... Hopefully Dan sends some UPA-1s to 'Secrets' and 'Audioholics...
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Post by sadams2206 on Apr 8, 2010 19:37:26 GMT -5
Reading through this thread has provided me with tons of information on these 2 amps, thank you to the folks who pointed me to the thread. I am still undecided though. The isolation of the UPA1 really intrigues me and was my initial choice, but the power of the XPA2 is also of interest. As discussed louder isn't always better and that is not my ultimate goal. I listen to music and movies about 50/50. I have magnepan 1.7s which is where my dilema comes to play. These speakers are rated at 4 ohms and their sensitivity is 86dB/Wm and I fear that the UPA may not have enough power to really push these speakers. Am I being foolish, can anyone comment on performance with a speaker with a similar sensitivity? I guess ultimately I am currently running an Sony AV which claims to output 125 wpc and I still haven't gone to the max volume, with that in mind I would assume the UPA power should provide more than enough volume for my room.
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Post by BillBauman on Apr 8, 2010 20:33:15 GMT -5
Reading through this thread has provided me with tons of information on these 2 amps, thank you to the folks who pointed me to the thread. I am still undecided though. The isolation of the UPA1 really intrigues me and was my initial choice, but the power of the XPA2 is also of interest. As discussed louder isn't always better and that is not my ultimate goal. I listen to music and movies about 50/50. I have magnepan 1.7s which is where my dilema comes to play. These speakers are rated at 4 ohms and their sensitivity is 86dB/Wm and I fear that the UPA may not have enough power to really push these speakers. Am I being foolish, can anyone comment on performance with a speaker with a similar sensitivity? I guess ultimately I am currently running an Sony AV which claims to output 125 wpc and I still haven't gone to the max volume, with that in mind I would assume the UPA power should provide more than enough volume for my room. Plenty of headroom, yes. I think the only difference you'll get is XPA = more forward, UPA = more refined. And you'll get better separation with the UPA-1's.
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ntrain42
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Post by ntrain42 on Apr 8, 2010 21:40:29 GMT -5
Reading through this thread has provided me with tons of information on these 2 amps, thank you to the folks who pointed me to the thread. I am still undecided though. The isolation of the UPA1 really intrigues me and was my initial choice, but the power of the XPA2 is also of interest. As discussed louder isn't always better and that is not my ultimate goal. I listen to music and movies about 50/50. I have magnepan 1.7s which is where my dilema comes to play. These speakers are rated at 4 ohms and their sensitivity is 86dB/Wm and I fear that the UPA may not have enough power to really push these speakers. Am I being foolish, can anyone comment on performance with a speaker with a similar sensitivity? I guess ultimately I am currently running an Sony AV which claims to output 125 wpc and I still haven't gone to the max volume, with that in mind I would assume the UPA power should provide more than enough volume for my room. Plenty of headroom, yes. I think the only difference you'll get is XPA = more forward, UPA = more refined. And you'll get better separation with the UPA-1's. The XPA-2's only advantage is about 1-2db more headroom. That ain't much. Unless max volume in a large room(with low sensitivity speakers) is your concern, the UPA-1's are a better choice. And if really more power IS needed over the UPA-1's(which are actually really powerful monoblocks as 200/350 watt numbers are nothing to sneeze at), I would bypass the XPA-2 and go to a pair of XPA-1's.
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Post by BillBauman on Apr 8, 2010 22:04:41 GMT -5
Plenty of headroom, yes. I think the only difference you'll get is XPA = more forward, UPA = more refined. And you'll get better separation with the UPA-1's. The XPA-2's only advantage is about 1-2db more headroom. That ain't much. Unless max volume in a large room(with low sensitivity speakers) is your concern, the UPA-1's are a better choice. And if really more power IS needed over the UPA-1's(which are actually really powerful monoblocks as 200/350 watt numbers are nothing to sneeze at), I would bypass the XPA-2 and go to a pair of XPA-1's. I agree.
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Post by orangeLollies on Apr 8, 2010 22:05:49 GMT -5
Plenty of headroom, yes. I think the only difference you'll get is XPA = more forward, UPA = more refined. And you'll get better separation with the UPA-1's. The XPA-2's only advantage is about 1-2db more headroom. That ain't much. Unless max volume in a large room(with low sensitivity speakers) is your concern, the UPA-1's are a better choice. And if really more power IS needed over the UPA-1's(which are actually really powerful monoblocks as 200/350 watt numbers are nothing to sneeze at), I would bypass the XPA-2 and go to a pair of XPA-1's. +1 Yep, I'm slowly side-stepping over to the other 'checkout queue' (UPA1s)... The more research I'm doing on amp & speaker science, the more I'm leaning toward the UPA-1s, as 'headroom' does not appear to be a limiting consideration anymore... and with all the benefits of a mono-block ;D
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Post by BillBauman on Apr 8, 2010 22:27:20 GMT -5
The XPA-2's only advantage is about 1-2db more headroom. That ain't much. Unless max volume in a large room(with low sensitivity speakers) is your concern, the UPA-1's are a better choice. And if really more power IS needed over the UPA-1's(which are actually really powerful monoblocks as 200/350 watt numbers are nothing to sneeze at), I would bypass the XPA-2 and go to a pair of XPA-1's. +1 Yep, I'm slowly side-stepping over to the other 'checkout queue' (UPA1s)... The more research I'm doing on amp & speaker science, the more I'm leaning toward the UPA-1s, as 'headroom' does not appear to be a limiting consideration anymore... and with all the benefits of a mono-block ;D Uh-huh. ;D I can't wait to hear these things. Mine will be here early next week. If they are as good I really expect them to be, I think these things are going down as one of the best values in high-end amplifier history. Honestly, a $350, 200wpc/8ohm monoblock built with high quality components? Seriously, if it makes sound and doesn't blow up my living room, then it's a champ.
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ntrain42
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Post by ntrain42 on Apr 9, 2010 9:32:15 GMT -5
The XPA-2's only advantage is about 1-2db more headroom. That ain't much. Unless max volume in a large room(with low sensitivity speakers) is your concern, the UPA-1's are a better choice. And if really more power IS needed over the UPA-1's(which are actually really powerful monoblocks as 200/350 watt numbers are nothing to sneeze at), I would bypass the XPA-2 and go to a pair of XPA-1's. +1 Yep, I'm slowly side-stepping over to the other 'checkout queue' (UPA1s)... The more research I'm doing on amp & speaker science, the more I'm leaning toward the UPA-1s, as 'headroom' does not appear to be a limiting consideration anymore... and with all the benefits of a mono-block ;D Hehe yeah, so many people I find really do not comprehend the output abilities of the UPA-1. In terms of power going from 200 watts to 300 watts 8ohms is identical to going from 50 watts to 75 watts at 8ohms, not really a big difference. Hell going from the UPA-1's to the XPA-1's itself is only a true 4db in linear output. Even that is not a really big difference. You need to double your power everytime just to gain 3db. To double the sound output(10db) you need 10 times the power. Those UPA-1 monoblocks are a bargain in reality. $600 for a pair cannot be beat.
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Post by BillBauman on Apr 9, 2010 10:07:36 GMT -5
I'm going to start a new thread: "BillBauman + ntrain42's UPA-1 Lovefest"
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ntrain42
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Post by ntrain42 on Apr 9, 2010 10:29:56 GMT -5
I'm going to start a new thread: "BillBauman + ntrain42's UPA-1 Lovefest" Well, it is what it is. Don't know another company that makes a good powerful monoblock for $300............unless you turn to the rack mountable pro audio dept.
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Post by moodyman on Apr 9, 2010 11:16:05 GMT -5
Honestly, a $350, 200wpc/8ohm monoblock built with high quality components? There have been several complaints that the binding posts on the UPA-1 are pretty lousy. And I still say that due to the fact that the XPA-2's transformer dwarfs the UPA-1 transformer and the XPA-2 has 12 outputdevices/channel vs 6 for the UPA the XPA-2 will supply significantly more current than the UPA-1 which would benefit people who like to blast their music/movies and not run out of juice during a particualry dynamic passge/scene. Do I think the UPA-1 is probaly a great amp?? I sure do...Do I think the XPA-2 provides more advantages to a user then just 1-2dB more headroom..yes. Am I slightly biased cuz I own an XPA-2?
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Post by BillBauman on Apr 9, 2010 12:24:55 GMT -5
Honestly, a $350, 200wpc/8ohm monoblock built with high quality components? There have been several complaints that the binding posts on the UPA-1 are pretty lousy. And I still say that due to the fact that the XPA-2's transformer dwarfs the UPA-1 transformer and the XPA-2 has 12 outputdevices/channel vs 6 for the UPA the XPA-2 will supply significantly more current than the UPA-1 which would benefit people who like to blast their music/movies and not run out of juice during a particualry dynamic passge/scene. Do I think the UPA-1 is probaly a great amp?? I sure do...Do I think the XPA-2 provides more advantages to a user then just 1-2dB more headroom..yes. Am I slightly biased cuz I own an XPA-2? No arguments from me here. If one or the other were clearly so vastly superior we couldn't keep our heads on straight listening to it, Emotiva wouldn't be selling both. As I've stated, I have the monoblocks rock bias. I would likely never buy an XPA-2, I just don't think its sound would be worth its cost - to me. I think its sonic signature will be similar to an XPA-5, 2-channels powered. At some point I'm going to get somewhere that I can listen to all of these at the same time and see if I agree or disagree with myself. Hopefully I can get someone to do the switching for me, I love blind A/B. The last thing I want is my own placebo effect setting in. Bring it on! If my ears can't hear it, I want to be the first to admit it.
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cgolf
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Post by cgolf on Apr 9, 2010 13:52:12 GMT -5
My UPA-1s are sitting in my living room waiting to be opened, hooked up and compared. I'll start that process tonight. I have some TSO that I have listened to multiple times (10x10... ;D) on the XPA-2 and that will be my comparison music tonight with the UPA-1s.
I've sold the XPA-5 in my game room so either the XPA-2 or the UPA-1s go in there for replacement.
1st place stays in the media room. 2nd place goes to the game room. No losers!!! ;D
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Post by monkumonku on Apr 9, 2010 13:56:44 GMT -5
My UPA-1s are sitting in my living room waiting to be opened, hooked up and compared. I'll start that process tonight. I have some TSO that I have listened to multiple times (10x10... ;D) on the XPA-2 and that will be my comparison music tonight with the UPA-1s. I've sold the XPA-5 in my game room so either the XPA-2 or the UPA-1s go in there for replacement. 1st place stays in the media room. 2nd place goes to the game room. No losers!!! ;D I for one, a happy XPA-2 owner, am eagerly awaiting your findings! Please don't delay!!
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Post by BillBauman on Apr 9, 2010 13:58:24 GMT -5
My UPA-1s are sitting in my living room waiting to be opened, hooked up and compared. I'll start that process tonight. I have some TSO that I have listened to multiple times (10x10... ;D) on the XPA-2 and that will be my comparison music tonight with the UPA-1s. I've sold the XPA-5 in my game room so either the XPA-2 or the UPA-1s go in there for replacement. 1st place stays in the media room. 2nd place goes to the game room. No losers!!! ;D I for one, a happy XPA-2 owner, am eagerly awaiting your findings! Please don't delay!! Yeah, cgolf, dude, seriously, we're waiting... It's been a good 15 minutes now. Ok, I just checked.. 6 minutes. But who's counting? ;D
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cgolf
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Post by cgolf on Apr 9, 2010 14:04:14 GMT -5
Hey Doc, give me an excuse to leave work and I'm on my way.. ;D This waiting is driving me crazy!!!!!!!!!!!!!!!!! ;D
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