Amazon.com: A Pair of KSA100 Gold Sealed Tube High Power HIFI Enthusiast Grade MJ15024G/MJ15025G A1930/C5171 Pure Rear Grade Adjustable Class A Power Amplifier Board : Electronics
Best Stereo Tube Amp under 1000 (2021 Reviews Updated) - AMP's HQ
My newest super-cheap Chinese tube amp
Cheap Chinese tube amp kit build (with better passive components and tubes) : r/audiophile