Picked up a Yaqin Tube amp to power my Chorus II speakers. So far I'm loving the sound but the Tubes are stock. I already changed out the driver tubes with some new JJ's. I'm looking for opinions on the EL34B power tubes. They currently have 6CA7 big bottle branded Yaqin (do they make their own?). I'm not even sure what I'm looking for in sound, but controlled bass, neutral warm highs, and wide soundstage would be ideal. I mostly listen at lower levels so rocking the house is not a priority. From reading multiple articles, I've narrowed down to the Genelix Gold Lion KT77 (most expensive), Tungsol EL34, or the Electro-Harmonix 6CA7. Any strong opinions on these choices? The Gold Lion's are almost twice as much as the others and wondering if I'll hear twice as good of an audible difference. Thanks in advance!