Which ECC83 / 12AX7 tubes are the best for the EAR834 phono preamp?

Due to the currently frequent inquiries about the China clone, we have dealt extensively with the EAR834 and tried many options. The best tube is the ECC83 Premium 12AX7 S4A, followed by the 12AX7G ECC803S Tung-Sol Gold Pin and the ECC83 Genalex Gold Lion. The S4A plays with good resolution, pleasant spatiality and many details, but not analytically. It remains pleasant and you can still tell that it is a tube preamp. The Tung-Sol is similar, but plays warmer, with a slightly smaller soundstage. The Genalex sounds a little more forward and open, but has slightly more noise than the other two. In our setup, the PSVANE Art and JJ ECC83S were not a good match.