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:
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:
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:
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:
As noted, noise is somewhat an issue and we can see that in signal to noise ratio:
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:
More complex speaker loads may make this worse (or better).
Crosstalk is OK:
Here is our power level versus distortion+noise at 4 ohm:
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:
So definitely not conservatively rated.
8 ohm load naturally produces a lot less power:
Typical of ICE modules, they don't behave evenly across the frequency range:
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.
Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
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:
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:
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:
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:
As noted, noise is somewhat an issue and we can see that in signal to noise ratio:
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:
More complex speaker loads may make this worse (or better).
Crosstalk is OK:
Here is our power level versus distortion+noise at 4 ohm:
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:
So definitely not conservatively rated.
8 ohm load naturally produces a lot less power:
Typical of ICE modules, they don't behave evenly across the frequency range:
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.
Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/