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Post by garbulky on Jan 24, 2018 15:27:10 GMT -5
But them why buy quad differential mono blocks if you're not going to use them to the best advantage. Cheers Gary Amen! I am loving fully balanced class A! |
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Post by nickwin on Jan 24, 2018 16:26:55 GMT -5
Of course garbulky is spot on, I'm going to disagree. Maybe it's because I run 2.1 for stereo music, have for decades, but a pair of XPA-1L's are my pick in comparison to an XPA-2. It's not even close, using the XPA-1L's quad differential fully balanced circuitry with long XLR cables but short speaker cables (a monoblock advantage) gives them a totally silent sound stage that the music just appears from. The XPA-2 just doesn't have that, plus the XPA-1L's extend it further with their Class A option. As many will say, the difference between them in Class A versus AB is very subtle and hardly noticeable, but with some instruments, recordings, music it's definitely a benefit. It's not that the XPA-2 is a noisy amp in itself, just that the XPA-1L has the hardware to take advantage of being a monoblock. Absolutely no cross talk of course, plus I can locate each one close by its respective speaker, a stereo amp can't do that. Even at my loudest (party time) listening volumes there is no way that the power supplies are being remotely stretched, At 92 db my speakers are not terribly inefficient, but whilst the listening area is compact the room itself is huge with cathedral ceilings plus I have applied some discrete acoustic work. There is no way I could sit in the room with the volume high enough to anywhere near extend the power supplies. Of which there are 2, one for each channel, so one channel isn't stealing power from the other. In my system it's really a no contest, maybe if I didn't use the XPA-1L's circuitry and monoblock advantages it might be closer. But them why buy quad differential mono blocks if you're not going to use them to the best advantage. Cheers Gary Thanks for sharing! I’m always glad to get varying opinions. Do you have any experience with the XPA1 or SA250? I have experience with both of those but not the xpa2. |
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Post by audiosyndrome on Jan 24, 2018 16:42:34 GMT -5
I would stick with your SA250. Others disagree (geebo and maybe gary), but I thought the XPA-2 gen 2 was better. I found the XPA-2 gen 2 to have more bass extension and dynamics than four (yes that's right) XPA-1 L's in a quad bi amped configuration. Also tried the regular 2 as well. The XPA-1 L's sound nice and smooth though. Definitely still a winner as expected. But if I had to pick, XPA-2 gen 2. I assume the SA 250 is even better but have never heard it. Interesting, the 1L's look so good on paper! That said the lack of bass extension/dynamics might point to the undersized power supply relative to the XPA2 and SA250. I feel like the 1L SHOULD have used a 600va transformer. I actually haven't heard the XPA2, but I have been REALLY enjoying the SA250. I did find that the SA250 has a different overall signature than the other Emotiva amps Ive used, did you find the XPA-1L had more or less the same sound signature as the other XPAs? Thanks for sharing! I read Gar's comments above as the XPA-1L is somehow limited in bass extension. Possibly in his system with his speakers. My NHT fronts go down to 25 Hz and I see (hear) no lack of dynamics or bass extension in my system. I can't comment otherwise as I've never heard the other amps mentioned. Russ |
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Post by nickwin on Jan 24, 2018 16:52:33 GMT -5
Interesting, the 1L's look so good on paper! That said the lack of bass extension/dynamics might point to the undersized power supply relative to the XPA2 and SA250. I feel like the 1L SHOULD have used a 600va transformer. I actually haven't heard the XPA2, but I have been REALLY enjoying the SA250. I did find that the SA250 has a different overall signature than the other Emotiva amps Ive used, did you find the XPA-1L had more or less the same sound signature as the other XPAs? Thanks for sharing! I read Gar's comments above as the XPA-1L is somehow limited in bass extension. Possibly in his system with his speakers. My NHT fronts go down to 25 Hz and I see (hear) no lack of dynamics or bass extension in my system. I can't comment otherwise as I've never heard the other amps mentioned. Russ I think he meant that XPA-1Ls bass was less extended relative to the XPA2, not necessarily that it was lacking in general. Also, I don't think more bass is always "better" or more accurate. Obviously bass can be over accentuated just like any other frequency. At the end of the day, how much bass is "just right" will always depend on the speakers and the room. Thanks for sharing! |
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Post by DavidR on Jan 24, 2018 16:57:03 GMT -5
I LIKE da bass. I also like detail in the treble.
I edited my previous post.
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Post by audiosyndrome on Jan 24, 2018 16:59:13 GMT -5
I also doubt that the designers at Emotiva pick transformers that are not capable of providing full rated power. And just looking at the kva rating may not tell the whole story. Perhaps the manufacturer of the transformers used in the 1Ls rates his transformers at 70 degrees C. Perhaps the transformers for the other amplifiers come from a different manufacturer who rates his transformers at 25 degrees C. Everyone is just guessing here without seeing schematics and component nomenclature.
Russ
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Post by audiosyndrome on Jan 24, 2018 17:01:19 GMT -5
I read Gar's comments above as the XPA-1L is somehow limited in bass extension. Possibly in his system with his speakers. My NHT fronts go down to 25 Hz and I see (hear) no lack of dynamics or bass extension in my system. I can't comment otherwise as I've never heard the other amps mentioned. Russ I think he meant that XPA-1Ls bass was less extended relative to the XPA2, not necessarily that it was lacking in general. Also, I don't think more bass is always "better" or more accurate. Obviously bass can be over accentuated just like any other frequency. At the end of the day, how much bass is "just right" will always depend on the speakers and the room. Thanks for sharing! OK. I see how you can look at it that way. No argument from me. Russ |
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Post by nickwin on Jan 24, 2018 17:02:52 GMT -5
Two known differences with the SA-250. 1. It has much lower gain than other emo amps. 2. It has a secondary winding on its tranformer. It has selectable gain: 29dB and 23dB <EDIT> (add): It has DUAL secondary windings. Most xmfr's have a primary winding and a single secondary winding. I believe that the SA-250 uses the two 2ndary windings to feed a single side of the amp i.e. one winding for the left side and the other winding for the right side. Whereas in an XPA-2 the single 2ndary winding feeds all the storage capacitors and both sides are fed power from a single source. That's why I say the SA250 is similar to a dual monoblock amp like this RPA-1: View AttachmentCorrect, most of the Emotiva amps use one shared transformer, independant secondary windings means each channel has its own secondary. Its basically half way to fully independent power supplies. I just didn't know the SA250 used this setup. Both ways have pro's and con's. With a shared supply any given channel can use the whole power supply which results in higher output per individual channel. A PS with Independent secondaries can only use its share of the total power supply and therefore will have less output per channel, but in theory they should have less crosstalk. Also, with a shared PS, if one channel hits the rails, all channels hit the rails. |
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Post by nickwin on Jan 24, 2018 17:11:21 GMT -5
I also doubt that the designers at Emotiva pick transformers that are not capable of providing full rated power. And just looking at the kva rating may not tell the whole story. Perhaps the manufacturer of the transformers used in the 1Ls rates his transformers at 70 degrees C. Perhaps the transformers for the other amplifiers come from a different manufacturer who rates his transformers at 25 degrees C. Everyone is just guessing here without seeing schematics and component nomenclature. Russ The thing is, there is no definitive answer to "how much is enough". Ask a Krell, Levinson, or Classe designer you will get a very different answer than from a Parasound or ATI designer which will again both be different than an Emotiva designer. In my book any PS that has less VA than rated output in wattage is a relatively weak PS. My understanding is that ~1.3va/watt (at the lowest rated impedance) is pretty much the gold standard but some high end amps use much much more. XPA1, XPA2 and SA250 all have beefier power supplies on paper than the XPA-1L . Of course with 8 ohm this is probably all moot and theory doesn’t always translate to the real world. Valid point about specs! |
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Post by Gary Cook on Jan 24, 2018 18:09:06 GMT -5
I'm pretty sure that I have posted this comparison before, but maybe a refresher here;
XPA-1L Power Supply: 90,000 uF of storage capacitance, 450 VA heavy duty toroidal transformer.
XPA-2 Gen 2 Power Supply: 45,000 uF of storage capacitance, 1200 VA heavy duty toroidal transformer.
Note that each XPA-1L has double the storage capacitance of the XPA-2. A pair of XPA-1L's added together means 4 times the storage capacity of the XPA-2.
In regards to transformer capability a pair of XPA-1L's has 25% less than the XPA-2.
We could debate the merits of storage capacity versus transformer output all day (in fact many days previously), the fact is neither have what anyone could remotely call whimpy power supplies, they both have more than enough grunt.
Personally I like a responsive amp (what I call "fast"), one that reacts to the dynamic changes present in music, has punch, vigor, slam, appulse, impact etc. As a result I'll take a 300% advantage in capacitance compared to 25% less in transformer any day.
Cheers
Gary
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Post by rdperry12 on Jan 24, 2018 18:10:09 GMT -5
It's funny this topic has come up as I have recently got my hands on a SA-250 and was comparing it with my RPA1 last night. I love my RPA but the SA250 is just a better amp in every regard. It is my favorite of all the Emo amps I have had. I haven't had the opportunity to try the xpa1l but I have had all the 2 channel amps but the XPR-2.
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Post by DavidR on Jan 24, 2018 18:15:22 GMT -5
Where was all this love for the SA-250 when Emotiva was trying to sell them and people were saying it was nothing more than an under powered XPA-2 at a higher price. So glad I jumped on it.
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Post by Gary Cook on Jan 24, 2018 18:22:44 GMT -5
I'm pretty sure that I have posted this comparison before, but maybe a refresher here; XPA-1L Power Supply: 90,000 uF of storage capacitance, 450 VA heavy duty toroidal transformer. XPA-2 Gen 2 Power Supply: 45,000 uF of storage capacitance, 1200 VA heavy duty toroidal transformer. Note that each XPA-1L has double the storage capacitance of the XPA-2. A pair of XPA-1L's added together means 4 times the storage capacity of the XPA-2. In regards to transformer capability a pair of XPA-1L's has 25% less than the XPA-2. We could debate the merits of storage capacity versus transformer output all day (in fact many days previously), the fact is neither have what anyone could remotely call whimpy power supplies, they both have more than enough grunt. Personally I like a responsive amp (what I call "fast"), one that reacts to the dynamic changes present in music, has punch, vigor, slam, appulse, impact etc. As a result I'll take a 300% advantage in capacitance compared to 25% less in transformer any day. I have owned both of the above amps, but I have no experience with an SA-250, but for completeness; SA-250 Power Supply: 40,000 uF of separate storage capacitance per channel, 1200 VA heavy duty toroidal transformer Being a stereo amp, the SA-250 seems to follow what I see as Emotiva's philosophy of much smaller capacitor storage coupled with slightly larger power supply capability. Surprisingly (to me anyway) it has slightly less storage capacity than the XPA-2 with the same rated transformer. But again no one could remotely call that a whimpy power supply. All 3 amps have what I'd consider "over the top" power supplies and us debating over which one is more over the top is a bit silly. Cheers Gary |
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Post by garbulky on Jan 24, 2018 18:29:31 GMT -5
I'm pretty sure that I have posted this comparison before, but maybe a refresher here; XPA-1L Power Supply: 90,000 uF of storage capacitance, 450 VA heavy duty toroidal transformer. XPA-2 Gen 2 Power Supply: 45,000 uF of storage capacitance, 1200 VA heavy duty toroidal transformer. Note that each XPA-1L has double the storage capacitance of the XPA-2. A pair of XPA-1L's added together means 4 times the storage capacity of the XPA-2. In regards to transformer capability a pair of XPA-1L's has 25% less than the XPA-2. We could debate the merits of storage capacity versus transformer output all day (in fact many days previously), the fact is neither have what anyone could remotely call whimpy power supplies, they both have more than enough grunt. Personally I like a responsive amp (what I call "fast"), one that reacts to the dynamic changes present in music, has punch, vigor, slam, appulse, impact etc. As a result I'll take a 300% advantage in capacitance compared to 25% less in transformer any day. Cheers Gary The XPA-2 has almost the same actual caps as the xpa-1 gen 2. However it is wired differently to give a much lower number. Edit: 180,000 mf wired in paralel to give 45,000 mf for some reason |
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Post by nickwin on Jan 24, 2018 18:33:56 GMT -5
Where was all this love for the SA-250 when Emotiva was trying to sell them and people were saying it was nothing more than an under powered XPA-2 at a higher price. So glad I jumped on it. There seems to be more than meets the eye with the SA250. |
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Post by nickwin on Jan 24, 2018 18:38:52 GMT -5
I'm pretty sure that I have posted this comparison before, but maybe a refresher here; XPA-1L Power Supply: 90,000 uF of storage capacitance, 450 VA heavy duty toroidal transformer. XPA-2 Gen 2 Power Supply: 45,000 uF of storage capacitance, 1200 VA heavy duty toroidal transformer. Note that each XPA-1L has double the storage capacitance of the XPA-2. A pair of XPA-1L's added together means 4 times the storage capacity of the XPA-2. In regards to transformer capability a pair of XPA-1L's has 25% less than the XPA-2. We could debate the merits of storage capacity versus transformer output all day (in fact many days previously), the fact is neither have what anyone could remotely call whimpy power supplies, they both have more than enough grunt. Personally I like a responsive amp (what I call "fast"), one that reacts to the dynamic changes present in music, has punch, vigor, slam, appulse, impact etc. As a result I'll take a 300% advantage in capacitance compared to 25% less in transformer any day. I have owned both of the above amps, but I have no experience with an SA-250, but for completeness; SA-250 Power Supply: 40,000 uF of separate storage capacitance per channel, 1200 VA heavy duty toroidal transformer Being a stereo amp, the SA-250 seems to follow what I see as Emotiva's philosophy of much smaller capacitor storage coupled with slightly larger power supply capability. Surprisingly (to me anyway) it has slightly less storage capacity than the XPA-2 with the same rated transformer. But again no one could remotely call that a whimpy power supply. All 3 amps have what I'd consider "over the top" power supplies and us debating over which one is more over the top is a bit silly. Cheers Gary I believe the XPA-2’s 45,000uf is total, not per channel. Not positive though. EDIT: looking at a pic of the xpa2 it looks like it is indeed total, not per channel. |
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Post by Gary Cook on Jan 24, 2018 18:40:32 GMT -5
I have owned both of the above amps, but I have no experience with an SA-250, but for completeness; SA-250 Power Supply: 40,000 uF of separate storage capacitance per channel, 1200 VA heavy duty toroidal transformer Being a stereo amp, the SA-250 seems to follow what I see as Emotiva's philosophy of much smaller capacitor storage coupled with slightly larger power supply capability. Surprisingly (to me anyway) it has slightly less storage capacity than the XPA-2 with the same rated transformer. But again no one could remotely call that a whimpy power supply. All 3 amps have what I'd consider "over the top" power supplies and us debating over which one is more over the top is a bit silly. I believe the XPA-2’s 45,000uf is total, not per channel. Not positive though. Quoted as per the Manuals, so I suspect that you are correct. Cheers Gary |
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Post by nickwin on Jan 25, 2018 9:05:13 GMT -5
I’m actually starting to wonder if the XPA-1l has two caps running in series resulting in an actual system capacitance of 45,000uf. That would put it much more in line with the rest of the lineup. If not it has substantially more capacitance per watt than any other Emo amp I am aware of.
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Post by nickwin on Jan 25, 2018 9:14:48 GMT -5
source="/post/926134/thread" author=" Gary Cook" timestamp="1516835346"] All 3 amps have what I'd consider "over the top" power supplies and us debating over which one is more over the top is a bit silly. Cheers Gary By what metric? AVR standards? These are hardly even avg by pro audio standards and I honestly cannot come up with a single monoblock from another reputable brand that has less PS than the XPA1l. 450VA for 500 Watts is not a big transformer. That said if the actual capacitance is 90,000 that is quite a lot. All the capacitance in the world can’t make up for an undersized transformer though. At 1.2va/watt the XPA1 and 2 would be just about avg by pro standards and the SA250 at 1.33va/watt would be slightly beefy. 1.33 is still not particularly beefy by quality consumer audio standards but I think it’s just about the sweet spot assuming an amplifier power factor (efficiency) of .7. Some comparisons: My entry level Crown stereo amp has 1va/watt Entry level Outlaw multichannel amp has 1.1va/watt Entry level ATI amps (Monoprice) 1.5va/watt Entry level Rotel stereo amp has nearly 3va/watt! Entry level Parasound 5 channel 1.33va/watt Parasound monoblocks 1.6va/watt @ 2 ohms or 2.4@ 4 ohms Xpa1l .9va/watt |
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Post by rbk123 on Jan 25, 2018 9:31:36 GMT -5
SA-250 Power Supply: 40,000 uF of separate storage capacitance per channel, 1200 VA heavy duty torroidal transformer So 80,000 uF total? If so, that puts it in between the XPA-2 at 45k and a pair of 1L's at 180k. No idea how that translates to sound, though. |
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