The PA5 II lists at € 164.14 on hifigo, but I am not sure if that is an expired sales price, because when you click on it, the price (with 19% German VAT) is € 193.11. But the A5 should really be compared to the PA5 II that has about 40% more power into 4 Ohms. It lists at € 251.33 on hifigo.
I have Amir's results for the A5 and PA5 II copied side by side. Unless the 15 kHz THD+N will tell us a different story, I'd still argue that aside from the power, the PA5 II is still a hair's breadth ahead:
- SINAD is identical
- 1 kHz 2nd and 3rd harmonic are 2 dB lower in the PA5 II (ok, that is within unit-to-unit variation), but maybe more significantly, harmonics in the 12 - 20 kHz range are about 8 dB lower for the PA5 II
- similarly, in the multitone IMD test, the grass in the 12 - 20 kHz range is about 5 dB lower in the PA5 II
- in two-tone IMD, 18 and 21 kHz products are about 2 dB lower in the PA5 II
- for the next order (16 andd 22 kHz), the PA5 II is aobout 8 dB lower
- (for the products around 38 kHz, the A5 is about 15 dB better, but I think this is owed to a steeper output filter rather than better transfer function linearity)
I did a similar side by side with archimago's tests of the A5 and PA5 II Plus, and they were more like head-to-head regarding SINAD and IMD, and with a (smaller) edge on output power for the A5 (4R: 121 vs. 102 W, 8R 62 vs. 56 W).
So other than the 10 - 20% higher output power (depending on whether you look at 4 or 8 R and the Plus version or not), I do not yet see what the A5 does better, even if it comes close or maybe draws equal.
How does the A5 achieve higher power? It does use 2x TPA3251 whereas Topping never told us what chip they use or how many.