The Aiyima specs are confusing and misleading. The
ASR review goes on to say
It all depends on how loud you want to listen. If you remember ohms law, voltage X current = power
36v 5A = 36 * 5 = 180 watts
48v 2.5A = 48 * 2.5 = 120 watts
If i'm not mistaken the Aiyima AMP has 300w + 300w output = 600 w. But in reality it never happens that there is music content that played will require 600 watts continuous output. Only for very short durations which has loud music passage with a solid bass will require such tremendous power. So in general, power supplies are fitted with large capacitors to supply full output for very short duration.
Since wattage = voltage X current, a power supply of 48 volts will give 600/48 = 12.5 A. The specs of Aiyima says it requires DC 48v with current over 7A. But I wouldn't ever run this AMP with a PS that can make the AMP deliver it's full power because this AMP doesn't have a good thermal design as per this
tear down by ASR. Amir goes on to say that he will never leave the power supply continuously on.
Max Output power | 300W+300W (4 ohm load,Under DC 48V,Current Over 7A) |
Audio input ways | 3.5mm AUX Audio input/ RCA Audio input |
Number of channels | 2.0 channels/Stereo |
Power supply | DC24-48V (outer diameter 5.5mm inner diameter 2.5mm) |
A power supply of 36 5A can give 36 * 5 = 180 watts continuous output while a PS of 48v 2.5 A can give 120 watts output which I feel is more than enough.
Also remember that with such high current, any short circuit on the output becomes a fire hazard. So the PS of 48v will reduce the value of current and make it safer compared to the PS of 36v 5 A. Remember heat generated = I²R, where R is the resistance of the load.
So both the power supplies will work but 48 v will reduce the current requirement for the same wattage. You can look at this table below from Aiyima itself as a guidline but will confuse anyone further. Also the same Aiyma brochure says
So in reality Aiyima has just picked up specs as it suits them from the TPA3255 chip and pasted 300w + 300w in bridged mode. But inspite of glarring crap in the specs, the amp is a low distortion amp and is value for money. I wouldn't read too much from the official specs and would rather buy this from hifimart which comes with the power supply.