Here's Why Vacuum Tube Amplifiers Are Reemerging on the Audio Scene – Robb Report
Audiomat Ópera Réference Class A Integrated Tube Amplifier, High End! – Holt Hill Audio
FX-AUDIO TUBE-P1 Valves Amplifier with Phono MM Input 6J1 + 6P1 Stereo Black - Audiophonics
10 Tube Amplifiers that Are Essentially Works of Art – Robb Report
Kora
Vacuum Tube French CSF 6080WA 6N5P 6080 6AS7 421A for Tube Amplifier HIFI Audio Amplifier Original Exact Match - AliExpress
Amazon.com: Dared I30BT HiFi Vacuum Tube Integrated Amplifier, Audiophiles Stereo AMP, 30W x 2 Output, DAC and Line Input, 6L6G, 12AX7, 12AU7 Tube : Electronics
Tube Power Amplifiers PA100 Jadis Electronics
Archimago's Musings: MEASUREMENTS: Melody Onix SP3 Mk. II (~2006) Class AB Tube Integrated Amplifier. (And it isn't "diminishing returns" on sound quality, often there are simply "no returns".)
HI-FI GEAR — Manley Laboratories, Inc.
Jadis JA80 Tube Monoblocks w/Sound Anchor Stands - Made In France
Audio Research VT80SE Tube Power Amplifier Review - HomeTheaterHifi.com
Amazon.com: Fosi Audio T20 Bluetooth 5.0 Tube Amplifier Headphone Amp Support aptX HD Stereo Receiver 2 Channel Class D Digital Mini Hi-Fi Power Amp for Home Passive Speakers with 6J4 Vacuum Tubes :
Willsenton R300 single ended 300B integrated | Headphone Reviews and Discussion - Head-Fi.org
The Miracle of a $150 (or Less) Tube Amplifier - WSJ