But I tried - the FX Audio Tube 03 will seriously make the sound worse. It is just not on par at all. I instead bought a clone tube preamp from aliexpress “Cary 90 SLP”. Much much better and actually make the sound more spacious and widens the stereo image.
Those “Cary 90 SLP” clones on AE are $320 versus the $25 FX-Audio Tube 03. That isn’t a fair comparison, and I doubt that is 12 times better, which is what it costs.
I think if you want want to part swap, learning to do it on something affordable makes sense, even if it isn’t high end. I build a solid state headphone amp in 2022, and while I don’t use it often, it was still fun to do, and I learned some things.
I have the xDuoo MT-602, totally stock with original tube, and I love it, but it was nearly $100. I am exclusively an IEM & headphone guy, and probably do less than 10% of my listening on my desktop setup. The Fiio KA17 is my most used DAC/Amp. I still use my BTR5 ( replaced by the BTR15 ) for mobile use.