here is my tube rolling experience w/ MHDT Orchid. (before & after mods by Grannyring)
Before mod:-
I had some OS 6SN7s laying around & NOS Tung Sol & Sylvania 2C51
Sylvania 2C51 sounded better...but not something I wanted to live with.
I got adapter from Garage1217....
Of all the 6sn7s..Sylvania Jan CHS 6sn7WGT was the best ...a bit flat, but something I can live with and enjoy the music.
But wanted to see if I can get better sound out of Orchid. After talking with 2 people, who offer mods for Orchid, I decided to use Grannyring. He was willing to tweak his mod to suite my music listening preference (cannot have bright sound at all)
After receiving the mod:-
1) The order of preference for 6Sn7s changed.
Tung-Sol UCn-CTL-6sn7wgta sounded better (more relaxed) than SYlvania.
2) Also the Sylvania 2C51 sounded much better.
almost seemed like the mod was specific to make 2C51 sound better.
So I tired the following 2C51/5670 family tubes