Quick update:
The folks from r/budgetaudiophile helped me out a bunch. They stated a few things:
- The differences between the Ayima A07 and SMSL amps with Infineon MA12070 amps are only slight. So I'm wondering if I'll notice a difference switching from my Tripath amp.
- Shoot for 70s and 80s amps in the vintage market. No need to spend over 100€. These amps should be well-built and over-engineered.
- I skimmed through my local classfields and found a bunch of really old vintage Marantz, Pioneer, Akai... amps for 100~600€. Most of the sellers live pretty far away. I'm kinda put off.
- I let the algorithm work in the background and I stumble upon lesser-known, lesser-priced brands like Dual and Continental Edison.
- I eventually purchase a Continental Edison PA 9109 (20W @ 8 ohm) for 40€ from an old guy who lives 2km away. He was also selling a bunch of NOS amplifier tubes from the 60s/70s for a few euros. But I'm no expert and I don't know where to resell those.
- The exterior of the unit is cheap and tinny. The bottom of the unit is fiber board. But peaking inside you can see the oversized components neatly layed out in a minimal layout. Regret kinda settles in.
- I hook the amp up and wow! It slaps. I don't even want to use a sub. The noise floor is slightly higher than the Tripath amp but still negligeable. Comparitively, the Tripath amp feels... grey. And so did my Yamaha RN402 amp from memory. Perhaps the Tripath would have sounded more exciting if I could increase the volume more. I haven't tried the Aiyima A07 yet so I can't comment more on that point.
Conclusion: Vintage Continental Edison amps are criminally underrated. Buy them while they're cheap. Pair them with decently resolving speakers and you'll be tapping your toes.