2 of
these cost 1500 EU tax included, more than twice the price for a few extra watts is wild.
The cost of the audiophonics.fr amplifiers based on the Purifi modules is attractive, agreed.
The two channel implementation has a tremendous write up from Amir (
https://www.audiosciencereview.com/...ics-hpa-s400et-review-stereo-amplifier.32014/) noting the "Purifi 1ET400A modules [are] fed by their own custom buffer/pre-amp gain stage". Audiophonics do not specify the op amps used in the buffers, but cannot be any other than very good, given the review. Unfortunately I am unable to find a dual-mono version on the web page, which would allow the buffer boards to be upgraded at some point in the future. It does not look like it is possible to replace the buffer board(s) with a drop-in upgrade.
On the monoblock versions there is a wiring cluster over the buffer boards with a very tight fit in the case, making may or may not make a difference.
The Audiophonics HPA-S400ET is
great value, based on Amir's review, but, given the layout of the monoblocks and the narrow-case two channel amplifiers, the measured performance may be a shade below that of the of the review sample.