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Weird phenomenon with Emotiva XPA Gen3

anphex

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Hi folks, greetings from Berlin!

due to a pretty big upgrade in my hifi system I came to occupy myself with looking for a fitting power amp. The speakers are Nubert NuVero 170 which are said to be very power hungry with 85db/1W and mercilessly monitor like (they are). I was powering them with a Denon AVR6400 but I was thinking it will reach it's power and distortion limits pretty soon.
So first I got an expensive Class D amp but I always felt that the sound was way too agressive and sharp in the highs which made me omit Class D for the future.
Next was an Emotiva XPA-5 Gen3 which I got with a pretty good second hand deal. This one sounded better than the Class D, but I felt weird listening to music on it. It all seemed a little mushy, pressed together or to but it plainly, as if a compressor was enabled. Transients like kicks, snares and quick sounds were kind of swallowed. To confirm that I wasn't going crazy I plugged back into my "cheap" Denon 6400 and indeed the life came back into the music. Good dynamics and lot's of punch even at rather high volumes. Now I am confused. What is happening there? I've read that Emotiva are actually Class H, meaning that they continously switch between different power rails as needed in very fine steps. Maybe the Emotiva power management is a few milliseconds too slow so the power can't keep up with incoming transients. But wouldn't that cause clipping instead of compression? I tested different modules of the XPA-5 and switched back and forth in disbelief. So far the Denon AVR6400 with its small A/B monoblocks takes the win.

This also made me wonder: Is this amp impulse response also tested in here? Does this even need testing? What would be the value to measure the max power spike of an power amp?

Edit to make a few things clearer: The XPA was already sold, but I am considering to bite into the sour apple once and get the Benchmark ABH2 which seems to be the endgame for power amps. BUT it says that it is also Class H so I am very cautious right now about anything that isn't true AB.
 
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AdamG

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Hi folks, greetings from Berlin!

due to a pretty big upgrade in my hifi system I came to occupy myself with looking for a fitting power amp. The speakers are Nubert NuVero 170 which are said to be very power hungry with 85db/1W and mercilessly monitor like (they are). I was powering them with a Denon AVR6400 but I was thinking it will reach it's power and distortion limits pretty soon.
So first I got an expensive Class D amp but I always felt that the sound was way too agressive and sharp in the highs which made me omit Class D for the future.
Next was an Emotiva XPA-5 Gen3 which I got with a pretty good second hand deal. This one sounded better than the Class D, but I felt weird listening to music on it. It all seemed a little mushy, pressed together or to but it plainly, as if a compressor was enabled. Transients like kicks, snares and quick sounds were kind of swallowed. To confirm that I wasn't going crazy I plugged back into my "cheap" Denon 6400 and indeed the life came back into the music. Good dynamics and lot's of punch even at rather high volumes. Now I am confused. What is happening there? I've read that Emotiva are actually Class H, meaning that they continously switch between different power rails as needed in very fine steps. Maybe the Emotiva power management is a few milliseconds too slow so the power can't keep up with incoming transients. But wouldn't that cause clipping instead of compression? I tested different modules of the XPA-5 and switched back and forth in disbelief. So far the Denon AVR6400 with its small A/B monoblocks takes the win.

This also made me wonder: Is this amp impulse response also tested in here? Does this even need testing? What would be the value to measure the max power spike of an power amp?

Edit to make a few things clearer: The XPA was already sold, but I am considering to bite into the sour apple once and get the Benchmark ABH2 which seems to be the endgame for power amps. BUT it says that it is also Class H so I am very cautious right now about anything that isn't true AB.
Welcome Aboard @anphex.
 

pozz

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Hi folks, greetings from Berlin!

due to a pretty big upgrade in my hifi system I came to occupy myself with looking for a fitting power amp. The speakers are Nubert NuVero 170 which are said to be very power hungry with 85db/1W and mercilessly monitor like (they are). I was powering them with a Denon AVR6400 but I was thinking it will reach it's power and distortion limits pretty soon.
So first I got an expensive Class D amp but I always felt that the sound was way too agressive and sharp in the highs which made me omit Class D for the future.
Next was an Emotiva XPA-5 Gen3 which I got with a pretty good second hand deal. This one sounded better than the Class D, but I felt weird listening to music on it. It all seemed a little mushy, pressed together or to but it plainly, as if a compressor was enabled. Transients like kicks, snares and quick sounds were kind of swallowed. To confirm that I wasn't going crazy I plugged back into my "cheap" Denon 6400 and indeed the life came back into the music. Good dynamics and lot's of punch even at rather high volumes. Now I am confused. What is happening there? I've read that Emotiva are actually Class H, meaning that they continously switch between different power rails as needed in very fine steps. Maybe the Emotiva power management is a few milliseconds too slow so the power can't keep up with incoming transients. But wouldn't that cause clipping instead of compression? I tested different modules of the XPA-5 and switched back and forth in disbelief. So far the Denon AVR6400 with its small A/B monoblocks takes the win.

This also made me wonder: Is this amp impulse response also tested in here? Does this even need testing? What would be the value to measure the max power spike of an power amp?

Edit to make a few things clearer: The XPA was already sold, but I am considering to bite into the sour apple once and get the Benchmark ABH2 which seems to be the endgame for power amps. BUT it says that it is also Class H so I am very cautious right now about anything that isn't true AB.
It was likely a gain staging issue, such as clipping the inputs of the Emotiva or running out of headroom with your Denon preouts (can only guess at this point).

Your reasoning about why it sounded like it did is incorrect. Too bad you sold the Emotiva, since you could have tried a few different configs.

Max/peak output of power amps is tested with a very short burst signal. It's included in the recent reviews here.
 
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anphex

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Thank you for your response! Yeah, I'm a little impatient when it comes to error searching, but in this case I saw no way to adjust anything for the better since the Emotiva have fixed input sensivity. Also the preouts worked very fine when I had the Class D plugged in. The only thing I could have tried was maybe using a chinch/XLR adaptor and use the XLR inputs.
 
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anphex

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I asked Emotiva support about this and after a while I got a response:

Hello! Thank you for your message.

I took a look at your speakers and I think I know why it sounds compressed. You are essentially running the amplifier right up on the internal limiter. As you mentioned already, your speakers are rather intensive @85 dB and have a 4-ohm impedance rating. What these specs tell me is that you need a lot more power but also an amplifier that can handle higher current to push a larger load to the speakers. For these speakers, you'd need something like our XPA-DR2 for the best results: https://emotiva.com/collections/amps/products/xpa-dr2

I understand this like the XPA has a lot of power on RMS(400W) but weak short burst peak power? So the Denon X6400 AVR has less RMS(about 160W) power but more short burst peak power? That can't be it, right? On the other hand this would explain the behavior.
 
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anphex

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Another update. I really appreciate that Emotiva seems to have dug deeper into this. I am not used to get such good support from manufacturers.
After some research, It looks like you may be maxing out/clipping the pre-out stage of the Denon. What you are then hearing is the amplifier amplifying a clipped/compressed signal which is not the amplifier's fault. The Denon you have appears to have a pre-out output voltage of 1.2V while the XPA-5 you have has an input sensitivity of 1.5V. This means you would have to turn the volume up rather high on the Denon to achieve louder volumes at which point the Denon is clipping the signal to keep up with the volume demand. Adding the DR2 might actually help your issue here since it has a lower input sensitivity at 1.1V. This means you don't need to turn up the Denon as much to get the desired volumes and you wouldn't be losing transients and other detail that is typically lost at volume levels that cause clipping (of the preamp or amplifier).

What do you think about this? I am kind of interested of trying it out I don't want to cause unnecessary trouble for the German reseller of emotiva and the package is also quiet havy and annoying to return.
 

AndreasW

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Another update. I really appreciate that Emotiva seems to have dug deeper into this. I am not used to get such good support from manufacturers.


What do you think about this? I am kind of interested of trying it out I don't want to cause unnecessary trouble for the German reseller of emotiva and the package is also quiet havy and annoying to return.

Well, what does MD-Sound (the german reseller) say? The last answer from Emotiva sounds reasonable. Its a pitty you sold the your amp already, i am looking for a used one (and live in Berlin).
 
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anphex

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I didn't take any further steps in this regard since my post above since it was an issue I never had with any amp in my lifetime and I am inclined to think that it's just some Emotiva quirk and that the DR2 won't be much different. Today or tomorrow I'll get my Hypex NC400 mono kits for my last try with Class D. If those aren't satisfying I will reconsider the Emotiva DR2.
 

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Will you build them on your own? Which ones have you ordered? I might buy Audiophonics ones. Maybe we can have a chat in Berlin and talk about amps ;-).
 
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anphex

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I saw too late that there is a German shop that sells them preassembled for +25 € each. Now I ordered them at boomaudio where they were cheaper and will build them buy myself. I hope I won't have to solder with the new kits but when it comes to it I am prepared :)
I don't know Audiophonics, to be honest I am net even that interested in amps, I just see ASR like a Stiftung Warentest for audio gear and make my decisions based on the price/value ratio of the gear. And Hypex is very high up there. Still, I am eager to see wether the Hypex NC400 have the same Class D sound and issue like the NuPower D. If that's the case, then I am more or less sure that Class D isn't just for me and I will look back to Emotiva or maybe even Benchmark ABH2, though this one hurts money-wise.
 

AndreasW

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I saw too late that there is a German shop that sells them preassembled for +25 € each. Now I ordered them at boomaudio where they were cheaper and will build them buy myself. I hope I won't have to solder with the new kits but when it comes to it I am prepared :)
I don't know Audiophonics, to be honest I am net even that interested in amps, I just see ASR like a Stiftung Warentest for audio gear and make my decisions based on the price/value ratio of the gear. And Hypex is very high up there. Still, I am eager to see wether the Hypex NC400 have the same Class D sound and issue like the NuPower D. If that's the case, then I am more or less sure that Class D isn't just for me and I will look back to Emotiva or maybe even Benchmark ABH2, though this one hurts money-wise.
Which store in Germany is selling preassembled? Can't find any.
 

MakeMineVinyl

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Emotiva's explanation sounds reasonable. Honestly though unless there is something strange going on with with your speakers, any class of amplifier should sound for all intents and purposes very close if not identical. Is your room extremely large and are you listening at very high volumes to need such high power outputs? At any rate, the Benchmark is as good as it gets and should serve you well.
 
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anphex

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Emotiva's explanation sounds reasonable. Honestly though unless there is something strange going on with with your speakers, any class of amplifier should sound for all intents and purposes very close if not identical. Is your room extremely large and are you listening at very high volumes to need such high power outputs? At any rate, the Benchmark is as good as it gets and should serve you well.

Even though they are a little exotic they are really just 85db/1w 4 ohm speakers. Nothing alien. And I would agree with if the two other amps with it's own quirks wouldn't have sounded "right". My room is rather small, has good acoustic treatment and the speaker distance in the sweet spot triangle is about 3 metres. I tend to listen rather loud but I won't probably surprass even 50 watt peaks. That's part of the reason I have my doubts that the XPA is hitting it's limits with 400 watt rms.

Which store in Germany is selling preassembled? Can't find any.

Here: https://www.soundimports.eu/de/hypex-nc400-94813975.html You must select the option for 25 €.
 

Abe_W

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Hi folks, greetings from Berlin!

due to a pretty big upgrade in my hifi system I came to occupy myself with looking for a fitting power amp. The speakers are Nubert NuVero 170 which are said to be very power hungry with 85db/1W and mercilessly monitor like (they are). I was powering them with a Denon AVR6400 but I was thinking it will reach it's power and distortion limits pretty soon.
So first I got an expensive Class D amp but I always felt that the sound was way too agressive and sharp in the highs which made me omit Class D for the future.
Next was an Emotiva XPA-5 Gen3 which I got with a pretty good second hand deal. This one sounded better than the Class D, but I felt weird listening to music on it. It all seemed a little mushy, pressed together or to but it plainly, as if a compressor was enabled. Transients like kicks, snares and quick sounds were kind of swallowed. To confirm that I wasn't going crazy I plugged back into my "cheap" Denon 6400 and indeed the life came back into the music. Good dynamics and lot's of punch even at rather high volumes. Now I am confused. What is happening there? I've read that Emotiva are actually Class H, meaning that they continously switch between different power rails as needed in very fine steps. Maybe the Emotiva power management is a few milliseconds too slow so the power can't keep up with incoming transients. But wouldn't that cause clipping instead of compression? I tested different modules of the XPA-5 and switched back and forth in disbelief. So far the Denon AVR6400 with its small A/B monoblocks takes the win.

This also made me wonder: Is this amp impulse response also tested in here? Does this even need testing? What would be the value to measure the max power spike of an power amp?

Edit to make a few things clearer: The XPA was already sold, but I am considering to bite into the sour apple once and get the Benchmark ABH2 which seems to be the endgame for power amps. BUT it says that it is also Class H so I am very cautious right now about anything that isn't true AB.
You are not alone...every class H I've tried ( emotiva, tonewinner, even the older Technics) has been returned. I've gotten too spoilt by a couple of class A amps. I am ok with some ABs as well. Class H and Class D are for the utilitarian Joes who look at graphs and watch movies. Class A and AB are for guys who wanna be submerged into the music.
 
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