Sorry for the delayed response. I haven't ordered the tubes because I have a NOS matched pair of 805s that use the top caps I'd like to try out first (I'm currently using the non-capped Psvane 805A-T). I'm waiting to hear back from Line Magnetic about whether the cage will fit when using the top-capped Psvane 805Ts with the lead wires/cap receptacles. I put the cage on when I'm not using the amp along with a makeshift dust cover. I'm glad to hear that you're enjoying the 508IA! I used the amp at NFB setting #3 for the first few months and then found that I liked it even more at NFB setting #2. Those Tung Sol VT 231 black plates are supposed to be fantastic! Please let us know what you think of them. I've really enjoyed my NOS Sylvania VT 231s (the only other 6SN7 I've tried aside from the stock tubes), and of course the Tung Sol 6sU7GTY black glass with black oval/round plates.