This is a review and detailed measurements of the Earthquake XJ-300ST stereo amplifier. It was kindly donated by a member for testing. It costs US $462.83 from the company website.
I like the compact packaging and old school but solid feeling switchgear. Likewise, having a low-pass filter (no doubt to drive subs for which they are famous), filter corner frequency and phase come in handy. And of course the integrated volume control. Back panel is typical with the exception of crossing terminals (for bridging):
12 volt trigger is icing on the cake.
Unit runs is a "class J" amplifier and was cool and comfortable during testing.
Amplifier Measurements
Here is our usual dashboard:
We have massive mains spike which I could hardly reduce no matter what I did. I am assuming it is internal leakage. Can't figure out why one channel is so much more distorted than the other. Averaging the two, the amp falls in "poor" category of all tested with a SINAD of 59:
Frequency response showed strong roll off at both ends of the spectrum:
There is a note about a 15 Hz high pass but nothing about the top end. I tested the programmable lowpass by more or less setting it to 80 Hz and got this:
Crosstalk is very poor:
SNR was poor likely due to high levels of power supply/mains noise:
Power is modest:
I have no idea how they have arrived at their power spec:
Finally, here is the 8 ohm performance:
Conclusions
Not much to hang your head on here other than the compact size and functionality. Not sure how it is suitable for subwoofer duty when it has so little power. Can't recommend it.
------------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
I like the compact packaging and old school but solid feeling switchgear. Likewise, having a low-pass filter (no doubt to drive subs for which they are famous), filter corner frequency and phase come in handy. And of course the integrated volume control. Back panel is typical with the exception of crossing terminals (for bridging):
12 volt trigger is icing on the cake.
Unit runs is a "class J" amplifier and was cool and comfortable during testing.
Amplifier Measurements
Here is our usual dashboard:
We have massive mains spike which I could hardly reduce no matter what I did. I am assuming it is internal leakage. Can't figure out why one channel is so much more distorted than the other. Averaging the two, the amp falls in "poor" category of all tested with a SINAD of 59:
Frequency response showed strong roll off at both ends of the spectrum:
There is a note about a 15 Hz high pass but nothing about the top end. I tested the programmable lowpass by more or less setting it to 80 Hz and got this:
Crosstalk is very poor:
SNR was poor likely due to high levels of power supply/mains noise:
Power is modest:
I have no idea how they have arrived at their power spec:
Finally, here is the 8 ohm performance:
Conclusions
Not much to hang your head on here other than the compact size and functionality. Not sure how it is suitable for subwoofer duty when it has so little power. Can't recommend it.
------------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/