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Post by teaman on Jul 19, 2021 12:49:13 GMT -5
Did you really just try to compare a 70 watt per channel amp against a 450 watt amp in price? I was being sarcastic  Thank you for clarifying, you never know in here....lol |
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Post by rbk123 on Jul 19, 2021 12:57:15 GMT -5
I remember a not too flattering review by Sound&Vision also, where I believe the measurements on an XPA-5 Gen 3 were out of whack. I also remember Dan coming in here after the review mentioning he was going to reach out to them to address the inconsistencies. I read them monthly, and have never seen any rebuttal from Dan or anyone else in regards to their findings. I believe that was Stereophile where he said the unit they sent them had an issue and he was going to dig up the specific amp and get things cleared up. Of course he never did. On Amir's numbers, I'm curious about 2 things: 1. Did he measure the prior gen amps and/or the BasX? If so, how were those findings? 2. Did Amir ever measure an amp, change the power cord to something supposedly better, and then re-measure? Oneguy's post about his DIY power cord made me think this would be one of the better uses of Amir's testing. Reading through the comments in that thread is pretty interesting - they sure do like their Class D amps. I can only assume those must measure better than A or A/B amps, since they love their numbers. |
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Post by goodfellas27 on Jul 19, 2021 13:33:05 GMT -5
I remember a not too flattering review by Sound&Vision also, where I believe the measurements on an XPA-5 Gen 3 were out of whack. I also remember Dan coming in here after the review mentioning he was going to reach out to them to address the inconsistencies. I read them monthly, and have never seen any rebuttal from Dan or anyone else in regards to their findings. I believe that was Stereophile where he said the unit they sent them had an issue and he was going to dig up the specific amp and get things cleared up. Of course he never did. On Amir's numbers, I'm curious about 2 things: 1. Did he measure the prior gen amps and/or the BasX? If so, how were those findings? 2. Did Amir ever measure an amp, change the power cord to something supposedly better, and then re-measure? Oneguy's post about his DIY power cord made me think this would be one of the better uses of Amir's testing. Reading through the comments in that thread is pretty interesting - they sure do like their Class D amps. I can only assume those must measure better than A or A/B amps, since they love their numbers. |
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Post by davidl81 on Jul 19, 2021 15:05:42 GMT -5
Eh, my DR-2 sounds amazing. I’m not super concerned at all about a measurement. And honestly there is a lot of really good here out there that the majority of us would never tell the difference between in a blind test.
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Post by goodfellas27 on Jul 19, 2021 15:16:53 GMT -5
Agree -- but the asked price to performance ratio is objectively questionable. Eh, my DR-2 sounds amazing. I’m not super concerned at all about a measurement. And honestly there is a lot of really good here out there that the majority of us would never tell the difference between in a blind test. |
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Post by davidl81 on Jul 19, 2021 15:18:40 GMT -5
It absolutely is not in the case of the DR-2. I don’t care what these measurements show. I know how good it sounds in my system compared to other amps, and it’s price point deliveries plenty of value.
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Post by rbk123 on Jul 19, 2021 15:32:27 GMT -5
On Amir's numbers, I'm curious about 2 things: 1. Did he measure the prior gen amps and/or the BasX? If so, how were those findings? 2. Did Amir ever measure an amp, change the power cord to something supposedly better, and then re-measure? Oneguy's post about his DIY power cord made me think this would be one of the better uses of Amir's testing. So no prior gen2/gen1 or BasX amps then (since I don't care about the headphone amp)? No amp measurements while trying different power cords (doesn't have to be an Emotiva amp)? |
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Post by goodfellas27 on Jul 19, 2021 15:45:14 GMT -5
He has videos with different power cables See the YouTube channel. Not Emotiva tho So no prior gen2/gen1 or BasX amps then (since I don't care about the headphone amp)? No amp measurements while trying different power cords (doesn't have to be an Emotiva amp)? |
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Post by garbulky on Jul 19, 2021 15:49:30 GMT -5
So no prior gen2/gen1 or BasX amps then (since I don't care about the headphone amp)? No amp measurements while trying different power cords (doesn't have to be an Emotiva amp)? Why power cords? |
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Post by rbk123 on Jul 19, 2021 16:01:07 GMT -5
So no prior gen2/gen1 or BasX amps then (since I don't care about the headphone amp)? No amp measurements while trying different power cords (doesn't have to be an Emotiva amp)? Why power cords? If there ever was a time when these measurements and graphs would be useful, it would be to see if power cords do or do not affect an amp's performance. Since interconnects aren't part of the testing setup, nor speaker wire, that pretty much only leaves power cords. Most don't believe a power cord affects an amps performance so this would actually be some useful science to support or rebutt that premise. |
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Post by rbk123 on Jul 19, 2021 16:11:37 GMT -5
He has videos with different power cables See the YouTube channel. Not Emotiva tho So no prior gen2/gen1 or BasX amps then (since I don't care about the headphone amp)? No amp measurements while trying different power cords (doesn't have to be an Emotiva amp)? Got a link? I checked and he has 46 videos, with a couple on speaker wires and a couple on interconnects, but nothing on power cords that I could see. I'd think it would be as straight forward a test as there is - provide the amp measurements with the stock power cord, then re-measure with different cords and see if there's any difference or not. Since his measuring doesn't really apply to real world music listening/performance, it applies perfectly to power cords. |
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Post by garbulky on Jul 19, 2021 16:31:23 GMT -5
If there ever was a time when these measurements and graphs would be useful, it would be to see if power cords do or do not affect an amp's performance. Since interconnects aren't part of the testing setup, nor speaker wire, that pretty much only leaves power cords. Most don't believe a power cord affects an amps performance so this would actually be some useful science to support or rebutt that premise. I'm not sure how much a power cable can change the outcome unless the gauge is too small and resistance too high. Now what would be interesting is to see how much max power the power supply (I assume the wall) is able to deliver. Also if the amp had poor noise rejection, the shared devices or power issues may have impacted the output on the test. An amp is supposed to be able to reject power supply aberrations, so it would not be good if the Emo amp is not as immune to power supply issues as expected, but it may end up showing a cleaner signal if it was tested on its own outlet. Keith said the Emotiva amp has a regulated power supply so it should be more immune to these issues. Amir mentioned that the testing was done on a shared 20A outlet. The other link over here showed the amp was capable of even more power than this test showed so it was probably limited by the power line for the higher end of the output. |
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Post by goodfellas27 on Jul 19, 2021 16:38:56 GMT -5
There are videos of review units he does and shows you the "differences" in cables. Also, Gene from Audioholic has done this. The best power cable is the one that comes with the unit. That's their conclusion. If you want dive in, here are the many links, but I am not going to look for it. www.audiosciencereview.com/forum/index.php?search/26083952/&q=power+cable&c[users]=amirm&o=relevance He has videos with different power cables See the YouTube channel. Not Emotiva tho Got a link? I checked and he has 46 videos, with a couple on speaker wires and a couple on interconnects, but nothing on power cords that I could see. I'd think it would be as straight forward a test as there is - provide the amp measurements with the stock power cord, then re-measure with different cords and see if there's any difference or not. Since his measuring doesn't really apply to real world music listening/performance, it applies perfectly to power cords. |
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Post by garbulky on Jul 19, 2021 16:43:45 GMT -5
(And, while too much distortion can be a problem, we are not in a contest to produce the world's lowest distortion amplifier.) [/div] [/div] I hear you on how much distortion is "really" a problem. The number is much higher than we think. However.... the DR-2 marketting page is all about how accurate this amplifier is. So the ad specifically says the amp is supposed to deliver the best "technical performance". once again "vanishingly low distortion" is clearly not the case with spurious harmonics at -65, not even middling performance here. We've seen lower distortion and nonlinearity with a non-balanced amp. Same story here The real ad should be this amplifier has more distortion than most current gen amps but it has lots more power and sounds great which I think is a fair assessment. For instance the Emotiva PA-1 has substantially less distortion and it's also quite a bit cheaper. |
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Post by rbk123 on Jul 19, 2021 21:22:46 GMT -5
Bummer. Would be pretty simple to just rerun the same tests and show the distortion/etc. numbers are the same (or not). Would be pretty conclusive evidence to finally settle things (pretty much at least). I'll keep digging around; seems he's pretty much focused on interconnect cables and the likes. |
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cawgijoe
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Post by cawgijoe on Jul 20, 2021 4:54:00 GMT -5
I remember a not too flattering review by Sound&Vision also, where I believe the measurements on an XPA-5 Gen 3 were out of whack. I also remember Dan coming in here after the review mentioning he was going to reach out to them to address the inconsistencies. I read them monthly, and have never seen any rebuttal from Dan or anyone else in regards to their findings. I don't own a Gen 3 amp, and doubt I ever will, as I am quite happy with my plethora of Gen 1 and 2 amps in my stable. I remember though that the THD was quite low on the first two generations of amps, and usually had test results posted to prove it. When Bryston amps can offer .004% THD in a 250 wpc amp into 8 ohms, I don't think distortion should be looked at as a non issue. It should be addressed promptly, and if design changes need to be made....make them. I realize Bryston costs significantly more than the Emotiva, but I believe this company still needs to reach for further refinement in order to stay relevant and in demand. The more poor reviews make their ways around the AV scene, the worse the reputation becomes. I think in the past Dan, Kathy, Keith and Lonnie have always been welcoming of criticism and have strived to do better, I hope that is still the case moving forward...because I still refer a lot of people in here! Tim I am quite happy with my Gen 3 XPA 5 amp. To me it sounds just as good if not better than the XPA 5 Gen 1 it replaced due to a failure. Could have repaired, but decided to trade it in. No regrets buying Emotiva amps. |
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richb
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Post by richb on Jul 20, 2021 10:56:22 GMT -5
So, let's see now, THD of 0.07% at 5 watts... on an amplifier that can deliver over 700 watts... and this is supposed to be so awful WHY?
If you're trying to find the world's best numbers...
I believe the current record for "lowest THD" is held by Halcro... (they start around $40k) And perhaps someday Amir will design an even better one... In the mean time... if you want an amplifier to listen to... pretty well everyone we know is quite pleased with our XPA-DR series...
Just looking at the Halcro DM58, the benchmark AHB2 bests it, often by an order of magnitude. The AHB2 has limited power, 100/180 WPC 8/4 homes and 380/500 WPC 8/4 ohms bridged. www.stereophile.com/content/halcro-dm58-monoblock-power-amplifier-measurements-part-2www.stereophile.com/content/benchmark-media-systems-ahb2-power-amplifier-measurementsI have setup an A/B switch driven by a 4 DAC MiniDSP SHD capable of level matching to .1 DB using DSP. I have compared the AHB2 to my old Sunfire and ATI AT525NC (NCore) amps and the AHB2 is cleaning with more detail in the high-end attacks, cymbals and such. Send me a DR2 and I'll let you know - Rich |
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KeithL
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Post by KeithL on Jul 20, 2021 11:19:37 GMT -5
Let me start by saying that I have not personally heard either the Halcro or the Benchmark amp... In the distant past Halcro clearly led the pack in terms of "ridiculously low THD numbers"... But it wouldn't surprise me if Benchmark has finally surpassed them...
I did have one of the original Sunfire Load Invariant Power Amps for several years...
However.... I would expect the nCore amp to sound at least slightly different with different loads (because if has a reconstruction filter which will interact, at least slightly, with different loads). (I've heard them and they sound fine to me... but different amps do sound slightly different.)
I thought the Sunfire amp I had sounded just fine... but it was not the best sounding amp I've ever owned. I am also forced to ask whether the "extra detail" you hear from the Benchmark is more accurate... or whether it might be artificially boosting the detail... Again, I haven't heard the Benchmark amp, so I don't have an opinion either way, but "more" is not always "better"... (And I can most certainly vouch for the fact that certain DAC chips DO create an artificial illusion of additional detail... which sometimes sounds nice but isn't necessarily more accurate.)
I should also point out that your MiniDSP is almost certainly making a contribution to the sound of the overall signal chain... And, unless you're using mechanical relays, so are the switches you're using... (And, as far as the people who insist that different cables sound different, they'll probably insist that different brands of relays do too. )
And, sorry, but I can't exactly send you one... But we DO have a 30 day return policy if you want to try one...  (And we don't get many of them back.)
So, let's see now, THD of 0.07% at 5 watts... on an amplifier that can deliver over 700 watts... and this is supposed to be so awful WHY?
If you're trying to find the world's best numbers...
I believe the current record for "lowest THD" is held by Halcro... (they start around $40k) And perhaps someday Amir will design an even better one... In the mean time... if you want an amplifier to listen to... pretty well everyone we know is quite pleased with our XPA-DR series...
Just looling at the Halcro DM58, the benchmark AHB2 bests it, often by an order of magnitue. The AHB2 has limited power, 100/180 WPC 8/4 homes and 380/500 WPC 8/4 ohms bridged. www.stereophile.com/content/halcro-dm58-monoblock-power-amplifier-measurements-part-2www.stereophile.com/content/benchmark-media-systems-ahb2-power-amplifier-measurementsI have setup an A/B switch driven by a 4 DAC MiniDSP SHD capable of level matching to .1 DB using DSP. I have compared the AHB2 to my old sunfire and ATI AT525NC (NCore) amps and the AHB2 is cleaning with more detail in the high-end attacks, cymbals and such. Send me a DR2 and I'll let you know - Rich |
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richb
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Post by richb on Jul 20, 2021 12:04:37 GMT -5
Let me start by saying that I have not personally heard either the Halcro or the Benchmark amp... In the distant past Halcro clearly led the pack in terms of "ridiculously low THD numbers"... But it wouldn't surprise me if Benchmark has finally surpassed them...
I did have one of the original Sunfire Load Invariant Power Amps for several years...
However.... I would expect the nCore amp to sound at least slightly different with different loads (because if has a reconstruction filter which will interact, at least slightly, with different loads). (I've heard them and they sound fine to me... but different amps do sound slightly different.)
I thought the Sunfire amp I had sounded just fine... but it was not the best sounding amp I've ever owned. I am also forced to ask whether the "extra detail" you hear from the Benchmark is more accurate... or whether it might be artificially boosting the detail... Again, I haven't heard the Benchmark amp, so I don't have an opinion either way, but "more" is not always "better"... (And I can most certainly vouch for the fact that certain DAC chips DO create an artificial illusion of additional detail... which sometimes sounds nice but isn't necessarily more accurate.) I should also point out that your MiniDSP is almost certainly making a contribution to the sound of the overall signal chain... And, unless you're using mechanical relays, so are the switches you're using... (And, as far as the people who insist that different cables sound different, they'll probably insist that different brands of relays do too. ) And, sorry, but I can't exactly send you one... But we DO have a 30 day return policy if you want to try one... (And we don't get many of them back.)
The MiniDSP has 4 DACs that permits copying, for example, 1 to 3 and 2 to 4. It is a DAC but the same DAC is used so it is a constant. I have also swapped the A/B and to eliminate cabling between the amps. The switch is a 12 pole A/B switch and also verified that there is no common ground. These are my observations but in a sighted A/B, is is well controlled. If you know what a cymbal sounds like, it is clear which one sounds right. I absolutely agree that amps can and do sound differently. It may be that feedback is less effective at higher frequencies but that is pure conjecture. - Rich |
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Post by muslhead on Jul 21, 2021 10:06:38 GMT -5
If you're happy, it is not bad :-) But this could scare off potential buyers. Emotiva should address it. Bad bad, I have both a DR2 and DR 3. Probably should have been addressed at the time of design, testing and definitely before release, no? |
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