A Very Pleasant Surprise
The poor ancient Kenwood, which is over 30 years old, has been powering a variety of my speakers for several decades. Over that time it has developed some grounding issues and the higher end intermittently becomes quite muffled making movie dialog a little hard to hear. As percussive maintenance and a quick flick to the equalizer resolves these problems, it has stuck around as it is still just good enough. There is also the fact that many modern amps do not have posts for bare wires, so an upgrade would likely involve new speakers as well as an amp. It also sports front and rear channels in addition to left and right, as well as one of the first incarnations of Dolby Surround, neither of which is provided by the Fosi TB10D TPA3255.
After a bit of work, the wire transplant was successful and the TB10D TPA3255 is ready to try powering an obnoxious amount of speakers. A flick of the power button and suddenly the room is filled with clearer and louder sound than it has been since I last pulled my NAD amp out for testing. The signal is just stereo, with no front nor rear channels but there was no question those channels were perfectly separated and fully audible all around the room.
The audio is not delayed at all compared to the source, though it certainly does overwhelm it. The amp offers very clean voice performance for watching TV, and there is no question the treble and bass switches do exactly as much as you’d expect. When swapping over to movies, the separation continues with the effects being just as loud as you like while not fuzzing out dialogue. The amp really shines when you fire up your favourite music, with very clear audio. Those that prefer a warm tone might not favour the TB10D TPA3255, as it doesn’t have quite the same warmth as the old Kenwood. The lack of Dolby Surround is telling, but that would not matter at all if these were used in a more normal fashion and hooked up to a pair of high end bookshelf speakers.