Some (and garbulky's in their number) contend that traditional "heavy iron" with LOTS of capacitance is the only way to go.
But the majority of the world is going in the other direction. Theoretically, and unless you want HIGH current at LOW frequency for SUSTAINED periods (think trance, synth, & pedal organ tones), the switching supplies are every bit as good as traditional supplies. The DIY car audio and subwoofer guys seem to prefer traditional supplies, but for 99% + of the music you'll ever listen to, you shouldn't ever be able to tell which type of supply is in the amp.
After all - DC power supply rails are judged on few things - Ideally - No voltage sag - As much amperage as the circuit will call for - Inaudible ripple & noise. Meet those criteria, and you're golden!
Now the traditionalists will NEVER agree, but I think switching supplies are just fine for audio.
Coming week's system:
Roon on a Mac Mini via USB to Black Ice Audio FX tube DAC MCM passive volume pot Emotiva PA-1 power amplifiers + Emotiva T2 speakers
I will answer with a question. Who cares? Listen...decide if you like it.
Personally, I would have cared years ago because people told me I should care. Now, I own Class D amps that people pay big $ for and say they are as good as any amps they have heard.
Why should I care what class they are? Only ancient history...IMHO... I do not care at all.
XMC-1 DIRAC Full; Oppo 105/Roku Ultra to Panny AE4000 w/106" screen; UltraRendu to LH Labs Geek Pulse X-Infinity; nCore nc400's or Prima Luna Premium Prologue to Maggie 1.7's; Rythmik F25; XPA-5 to CC-470v3 Center/ERD-1's; Thorens TD166 MkII/Denon DL207/XPS-1; 5-zone Sonos w/Def Tech AW5500's @ deck/pool/master bath & Sony SS-MB105/Polk R10 @ great room & kitchen. Two headphone setups: Hifiberry/BasX A100 and Allo BOSS/Schiit Asgard 2 (each to Senn 600's). PC w/Airmotiv 3b's. Roon user.