Out of interest I bought one of these;

https://www.ebay.co.uk/itm/TPA3116-D...72.m2749.l2649

It's ridiculous. Just finished a 20-minute session and my ears are ringing like hell - this thing is damn loud and barely gets warm. I used a tube preamp pedal straight into it and got a really big sound with plenty of low-end thump-in-the-chest. If there's one drawback it's that there's a steep fall-off in the top-end, possibly caused by the excessive filtering necessary for a digital amp. Easily corrected by turning up the treble on the preamp. It's also susceptible to noise and needs an enclosure rather than sitting on a sheet of paper on my bench. So cheap it could be considered a consumable and you can buy 6 for the price of a single EL34.