Please answer for dummies: Any way to increase power from a Chinese tube amp?

I decided to set up a second audio system in my bedroom mostly to learn and play around with.  Initially I had an old Marantz receiver but became interested in some of the Chinese knock-offs.  I bought a pair of the Mistral "LS3/5a" speakers and was pleased with them for the price.  Then I decided to see what a vacuum tube amp sounded like and bought a Chinese tube amp (Reisong 12 watts per channel).  I like that too except that now I am wanting to play it louder and some sources seem to have less volume than others.  So...I was wondering if there is anything I can do inexpensively that would would work with the Chinese tube amp to give it more power.  I listen to everything from classical to 70s rock to jazz and country and I mostly either stream from Amazon Prime via a Sonos Connect or play vinyl on my Teac TN300 with an Ortofon 2M Red or listen to an occasional CD on my Denon DCD 620.  I am nearly 80 and can't afford to purchase new audiophile level pieces. And did I say that I do not understand most of what I read on these threads so write simply.