Researching a bit on the topic, though without understanding much of the technicalities, it seems that changing tubes should be able to result in both getting slightly more watts out of a tube amp, also changing it's tone notable as well as some tubes are are claimed to be easier to push into overdrive territory. I also picked up that the max output of the amp will be determined by the output transformer and that changing to different tubes will require a bias adjustment of the amp according to the tubes you use. Honestly I don't know what much of this means. The specific amp in question is a Dynacord Bass King all tube amp that is rated 50W utilizing 1 X ECC83 type tube in each of the 3 input stages, where I in reality only use one, the instrument input, and 2 X EL34 type tubes in the poweramp stage. Also I should add that as something unusual of amps from this era, the amp was produced in '63/'64, it both has an input gain control and a master volume. Now say I wanted to try to push the most watts out of it, which tubes might I then try using, and would it need any form of adjustments and/or surgeries to be able to utilize these new tubes/extra watts gained? Also say I would want to attempt to push it into overdrive, as it seems to keep amazingly clean all through it's output spectra as it is now, even with input gain set at max, which I use as default setting, which tubes could I eventual try to swap with what kind of tubes to possible achieve this, and again would such a change require any other changes to the amp than just swapping the tubes? To be perfectly honest I haven't looked into which tubes are used in my amp currently, as they had just been replaced with new ones before I received it, and I can't easily find out as the amp at the moment is located at our rehearsal place. But if I interpret the information the seller send with the amp, the tubes could very well be respectively JJ ECC83S/12AX7, 7025 tubes in the preamp stage and JJ EL34/6CA7 tubes in the poweramp stage, not entirely sure if this in fact is correct though, and, if it is, what that would mean and if those are good tubes and not least good tubes for what I had in mind.