Getting the itch to roll again

I built my VTA ST-70 about this time last year. My small signal tubes are some NOS JAN Sylvania 1967 6189. I started with the new production Tung-Sol EL34B which I liked but have since moved on to some new production Tung-Sol 6550 for the power tubes. I use this amp mostly as my desktop amp with some Wharfedale Diamond 220 speakers and Macbook Pro/Audioquest Dragonfly Red as the source. I have taken it down to listen with my main system sometimes. Main system is Monitor Audio Silver 8 speakers with either Marantz NA6005 network player, Oppo BD-105 disc or U-Turn Orbit Custom turntable with Ortofon 2M Red cartridge as the source. I really like the combo of the JAN Sylvania 6189 and Tung-Sol 6550 in either system but getting the itch to roll. The 6550 sound clearer over the bandwidth than the 34B. Music selection is all over the place. Anybody running KT66 or 7581a? Should I look to some other small signal tubes? Can't go crazy on the budget. Loaded questions I know. What are you all running these days?

Run KT-66's in mine, 1967 RCA clear tops and a 5AR4 rectifier with diode mod. Have rolled input tubes but love the RCA's. Have not messed with the KT-66's because they are great. God Lions.