Just curious, but what are your qualifications for stating this?
I could tell you I've worked with audio for years and seen and repaired countless DACs, ADCs, pre-amplifiers and power amps, and that would be as good as saying I was an ex-Capcom employer, but honestly I couldn't give a flying fuck about it, so just take a look at the board and see it for yourself:
https://www.arcade-projects.com/forums/index.php?threads/capcom-q-sound-amp-help.1291/post-17063 (thanks to
@acblunden2 for the pic)
Nothing magical, that would be the exact same circuit you'd find on low end amplifiers.
And just to make sure: all the filtering and phase shifting is done during the recording process and then you just need a stereo set up to enjoy it, otherwise you'd need special equipment and this wasn't the goal of this technology (to know more about this:
https://en.wikipedia.org/wiki/QSound ), hence some albums were marketed as "recorded in Qsound" like The Soul Cages from Sting or Amused to Death by Roger Waters (i have both, nothing groundbreaking, although very well engineered, just like most material from that era).
But if you enjoy having a Q-Sound amp in your cab there's nothing wrong with it, but, IMHO, you'd better get a cheap modern amp and stick with it which will give you a better sound experience.