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XTZ EDGE A2-300 Review (amplifier)

amirm

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#1
This is a review and detailed measurements of the XTZ A2-300 class D amplifier. It is on kind loan from a member and costs US $500 from the company direct (which is located in Europe). It is based on B&O ICE 300ASC or its newer name, 300A1.

While you won't mistake the enclosure for A2-300 as a high-end, custom design, it has enough extra touches to set it above typical DIY type cases:

XTZ A2-300 Review Class D Amplifier.jpg


There are some nice looking vents on the side. Note however that all the heat is centralized in the center bottom panel as is typical of class D amp modules. In use though, the bottom barely got warm although I could smell heat generation through side vents.

I was disappointed to not see balanced inputs:
XTZ A2-300 Review Class D Amplifier back panel.jpg


The gain potentiometer will make the unit flexible but they are typically not good for reliability. Since these controls don't get used often, then tend to go bad. If you buy this unit, be sure to turn the control left and right once a few months.

Binding posts are substantial which I liked.

XTZ A2-300 Measurements
As usual, we start with our dashboard of 5 watts into 4 ohm:
XTZ A2-300 Measurements Class D Amplifier.png


As noted, I adjusted the gain control to give me roughly 29 dB which is the standard value I use for my testing (and matches the THX recommendations). Distortion is fairly low at -98 dB or so but there is enough noise to cost you 10 dB and a bit more in the other channel. This makes SINAD still above average:
XTZ A2-300 Review Class D Amplifier.png


As noted, noise is somewhat an issue and we can see that in signal to noise ratio:

XTZ A2-300 Measurements SNR Class D Amplifier.png


Notice how one channel is 3.5 dB worse than the other.

I was a bit disappointed to see frequency response being impacted by my simple resistive load, showing peaking around 20 kHz:
XTZ A2-300 frequency response Measurements Class D Amplifier.png


More complex speaker loads may make this worse (or better).

Crosstalk is OK:
XTZ A2-300 Measurements crosstalk Class D Amplifier.png


Here is our power level versus distortion+noise at 4 ohm:

XTZ A2-300 Measurements Class D Amplifier power into 4 ohm.png


We see the same noise differential here and some distortion differential as well (although the latter is somewhat common). Power is way short of 300 watts. Letting distortion rise to 1% which is what the spec calls for, we are still shy of that:
XTZ A2-300 Measurements Class D Amplifier max and burst power into 4 ohm.png


So definitely not conservatively rated.

8 ohm load naturally produces a lot less power:
XTZ A2-300 Measurements Class D Amplifier power into 8 ohm.png


Typical of ICE modules, they don't behave evenly across the frequency range:

XTZ A2-300 Measurements Class D Amplifier power versus frequency versus distortion.png


That is quite a variation in distortion and noise relative to power. In some sense then our previous tests using 1 kHz are not as representative of the total performance.

Conclusions
I started the review liking the enclosure. But then got a bit more jaded with unbalanced only inputs, and higher than expected noise level, high frequency dependency on both frequency response and distortion+noise. Then again, performance is still above average compared to many amplifiers I have tested. This produced a quandary for me. I could recommend it and justify it. At the end, I decided to not recommend it but without strong feelings one way or the other. You have the data to decide for yourself.

------------
As always, questions, comments, recommendations, etc. are welcome.

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sigbergaudio

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#2
Fun to finally see a review with measurements of this unit, shoutouts to the member who sent it to Amir!

A bit disappointing results, I have two of these units and have been very happy with their performance - especially given the price.

With regards to power levels, I think XTZ suggests the gain control can be used as a max volume limiter. Could we perhaps expect it to reach the rated 300W if the gain was increased? Where was the gain level at when tested at 29dB gain? (1/2, 3/4 of max?)
 

vkvedam

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#3
Finally, thanks. Another one got ticked off the list, phew! Search continues...
 
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amirm

amirm

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Thread Starter #4
With regards to power levels, I think XTZ suggests the gain control can be used as a max volume limiter. Could we perhaps expect it to reach the rated 300W if the gain was increased? Where was the gain level at when tested at 29dB gain? (1/2, 3/4 of max?)
The position is as you see in the picture. And no, you can't get more power as it clips at this level already and protection circuit current limits. This happened at 1.2 volts so definitely no more juice to be had. It could be power supply limited.
 

digitalfrost

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#5
Use this as a subwoofer amplifier with a AHB2 for the satellites. I wanted something that uses low power and can be on all day. Bit disappointing results, but for the money it's alright I guess.

Crown XLS 1502 could be a good alternative. It has worse SINAD, but also more power, features and costs less. It's doesn't necessarily look like it belongs in a living room though.

Given it clips at 1.2v input, that means for a 2v output DAC, I should put the volume at -4.4dB so it doesn't clip at full scale, right?
 
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amirm

amirm

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Thread Starter #6
Given it clips at 1.2v input, that means for a 2v output DAC, I should put the volume at -4.4dB so it doesn't clip at full scale, right?
Well, you would be setting the volume to whatever listening level you want. :) If you turn it up too much the amp will clip and you will hear it. If not, then you are already below the max level.
 
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#8
Thanks for this very useful review. I'm considering these amps for surround duty in my home theatre.

Now the only untested amp among the modular designs remains the Ice Edge 1200AS2 which I currently use for my L+R speakers.
 
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#9
Finally! A measurement of this unit. Rather disappointing. Looks like Hypex NCore and siblings are still the better option. It is a great audiophile injustice that despite being manufactured in my country (Malaysia), the Hypex modules are NOT available for purchase directly in Malaysia. The modules are shipped all the way back to the Netherlands and then can be purchased from there and shipped back to the original country at great expense. Just have to bite the bullet.
 

martijn86

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#10
I'm glad to see EU Internet direct companies get some love here. I had no idea how XTZ would do with a full range amplifier but I know they use a similar amplifier in their Edge line of subwoofers and they seem to be great performers at very competitive prices.

Are there more EU Internet direct audio companies that people can share with me?
 

Tangband

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#11
Finally! A measurement of this unit. Rather disappointing. Looks like Hypex NCore and siblings are still the better option. It is a great audiophile injustice that despite being manufactured in my country (Malaysia), the Hypex modules are NOT available for purchase directly in Malaysia. The modules are shipped all the way back to the Netherlands and then can be purchased from there and shipped back to the original country at great expense. Just have to bite the bullet.
Yes it was disappointing. It seems that Aiyima a07 shows better measurements than this XTZ in some ways.
 

Matias

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#12
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hmt

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#13
Fun to finally see a review with measurements of this unit, shoutouts to the member who sent it to Amir!

A bit disappointing results, I have two of these units and have been very happy with their performance - especially given the price.

With regards to power levels, I think XTZ suggests the gain control can be used as a max volume limiter. Could we perhaps expect it to reach the rated 300W if the gain was increased? Where was the gain level at when tested at 29dB gain? (1/2, 3/4 of max?)
I Think the power supply gets you 440W (this is what I read somewhere). So you get about 400W out of the amps which is quite what Amir meaured. The 300W figure is 4 Ohms and one 1 channel driven.
 

DSJR

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#14
Finally, thanks. Another one got ticked off the list, phew! Search continues...
You know, I don't think this amp measures any worse than a significantly far more expensive Naim amp confection and that's current models tested to have up to 20dB better distortion than the old 'CB case' models I used to sell in the 80's - I'm using fairly recent Stereophile measurements and 80's 'Choice tests here.

By ASR standards, this amp isn't cheap. In domestic audiophile land, it's beer-budget I reckon.
 

Matias

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You know, I don't think this amp measures any worse than a significantly far more expensive Naim amp confection and that's current models tested to have up to 20dB better distortion than the old 'CB case' models I used to sell in the 80's - I'm using fairly recent Stereophile measurements and 80's 'Choice tests here.

By ASR standards, this amp isn't cheap. In domestic audiophile land, it's beer-budget I reckon.
See it for yourself. :)
https://docs.google.com/spreadsheets/d/1ZlTOYxmPs938gqHjtDABkWS-MApu7uJjzIGnJ2Elm6Y/edit?usp=sharing
 

pma

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#16
Thanks for the review, @amirm . The measurements result is not nice, output spectrum is dirty and noisy, and the amplifier non-linearity is very bad between 5 and 15kHz. I see no advantage compared to cheap AIYIMA A07, except for "nicer" case, implemented power supply and probably bigger heatsink. On the other hand, the power supply inside the unit degrades output noise. Will you post a photo of the unit without the top cover?

BTW, there seems to be higher freq. response peaking with 4ohm load than with 8ohm load and this is strange. Aren't the 4 and 8 ohm plots swapped?
 
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Ron Texas

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#18
OK actually. This amp might be a nice companion for a MiniDSP 2x4 HD due to its higher than average sensitivity for modern class D amplifiers and unbalanced inputs.
 

hmt

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#19
Thanks for the review, @amirm . The measurements result is not nice, output spectrum is dirty and noisy, and the amplifier non-linearity is very bad between 5 and 15kHz. I see no advantage compared to cheap AIYIMA A07, except for "nicer" case, implemented power supply and probably bigger heatsink. On the other hand, the power supply inside the unit degrades output noise. Will you post a photo of the unit without the top cover?

BTW, there seems to be higher freq. response peaking with 4ohm load than with 8ohm load and this is strange. Aren't the 4 and 8 ohm plots swapped?
As I see the usual PSU delivered with that amp is 32V and 5A. The XTZ will be significantly more powerful that that, even when you use a 48V PSU.
 
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