Tried tubes and LOVED it, now what?

Have it modded by someone who really knows their stuff.

I took a look at the circuitry of the unit and the design is nicely simple with no real circuit boards.

A prime candidate for easily noticeable qualitative upgrades. Ie, where the work done ---is easily heard.

Mods done? maybe $400 tops.

Upgrade? selling hassle and spend twice the money for little change upward and probably a notable amount of lateral shifting.

I enjoyed a Jolida 502P for years with a very substantial dual mono balanced blah blah preamp (Kavent S-33 Vincent clone), and those were great together (I've been tube guitar amp user for 5 decades). I started learning more about "single ended" tube amps (one of my newer "boutique" guitar amps is single ended) and happened upon a slightly used Dennis Had Firebottle SEP HO (High Output single ended pentode) on Ebay. A relatively low power amp does limit you to higher sensitivity speakers, so there's that, but my Klipsch Heresy IIIs are 99db so this rig can kick it. I also bought a new Schiit Freya so it's all tubular around here, and I've never looked back...the sound my gear pile is now astonishingly well sorted.

First off congrats on finding the light......I'm not a fan of KT88's,great bass but the mids are no where near as lit up as EL34...You could:
Consolidate all speakers to 1 pair of Hi Eff.& go 300B SET or something S.E.Triode Strapped or 300B Push Pull...
 Consolidate all speakers to 1 REALLY good pair & try some tube rolling,especially the small signal tubes along with some cable rolling...
 Stick with what you have & try tube/cable rolling...
Is the room treated?You will be surprised how much an untreated room affects the tone...Good luck...

@freediver the kt88 tubes were replaced with el-34s by seller and I liked the result. My room is (overly) treated with acoustics foams and panels. Ive been having fun playing with diff power cords and ICs but so affraid on trying diff tubes, bias, rolling etc. I don’t mind keeping the amp for a bit longer.
@teo_audio   Who is here familiar with modding the cayin A88-T will h great result?