Took your advice and got a LA90 for comparison. This comparison will not be meaningful for some, unless you have very low distortion equipment in front of these amps. Here is how I see it:
LA90 is tonally neutral, ultra transparent, has lowest distortion and reveals low level details incredibly well (most audiophiles have not heard this level of transparency). Worth $900 but wish it was 150 watts at the price--for me--a keeper.
Topping PA5 is tonally neutral, transparent, very low distortion and reveals low level details almost as well as LA90--maybe 95%. Wish it had more power but at $400, it's a steal (according to some feedback, it can have quality issues--mine does not)--for me--a keeper.
Purifi Eigentakt is tonally neutral, low distortion, but not as transparent as either--maybe 80%. Has enough power (a big plus) and great control of speakers. For me--not a keeper after having heard the other two.
BPT/Chris H.
LA90 is tonally neutral, ultra transparent, has lowest distortion and reveals low level details incredibly well (most audiophiles have not heard this level of transparency). Worth $900 but wish it was 150 watts at the price--for me--a keeper.
Topping PA5 is tonally neutral, transparent, very low distortion and reveals low level details almost as well as LA90--maybe 95%. Wish it had more power but at $400, it's a steal (according to some feedback, it can have quality issues--mine does not)--for me--a keeper.
Purifi Eigentakt is tonally neutral, low distortion, but not as transparent as either--maybe 80%. Has enough power (a big plus) and great control of speakers. For me--not a keeper after having heard the other two.
BPT/Chris H.
FYI:
Received my Connex 300 64V supply (added some low ESR caps on the output) and it sounds great. Overall, very similar to the stock LA90 supply (using the stock LA90 DC power connection cord) with just a tad more solidity in the lower midrange. Looking inside the LA90, the DC power connection from the back panel to the amp board is a nice pair of 14 AWG wire, however their stock DC cord to the unit is 1m of 18AWG---this makes no sense--to do it right inside the unit but wrong going to the unit. So, I made up a new DC power connection cord twisted pair, using 14AWG UPOCC copper wire about 1/2m long. Now we're talking. Overal it sounds smoother, ever so slightly more powerful and even more transparent. A mod worth doing but since it voids warranty--not for the faint of heart.
CJH
Received my Connex 300 64V supply (added some low ESR caps on the output) and it sounds great. Overall, very similar to the stock LA90 supply (using the stock LA90 DC power connection cord) with just a tad more solidity in the lower midrange. Looking inside the LA90, the DC power connection from the back panel to the amp board is a nice pair of 14 AWG wire, however their stock DC cord to the unit is 1m of 18AWG---this makes no sense--to do it right inside the unit but wrong going to the unit. So, I made up a new DC power connection cord twisted pair, using 14AWG UPOCC copper wire about 1/2m long. Now we're talking. Overal it sounds smoother, ever so slightly more powerful and even more transparent. A mod worth doing but since it voids warranty--not for the faint of heart.
CJH