I am glad you like your BHSE. Another set of NOS tubes coming your way from me soon as well. Enjoy.
BTW would you say the tube upgrade from stock is worth the cost v SQ hike? I noticed quite a difference in smoothness especially in the treble on David's BHSE with the 009s. So I did prefer the sound with those NOS Mullards in. The amp with stock tubes to me sounded brighter.
Thanks Julian. Honestly I don't even care enough to even get a new-stock set for comparison (and re-bias twice, etc). I've done plenty of tube-rolling in various amps, and even with output & driver tubes slots that are supposed to be "not sensitive" to tube rolling, there is a substantial difference. There are exceptions when you have an amp build that forces such a strong voice of its own (e.g. VAC gear), but I don't think that applies to the BHSE design.
When possible, I've always preferred vintage tubes over new stock, and I almost always find the differences more than worthwhile (I run KT120 in my monoblocks because I need 12 and that's not realistic to get in vintage KT88; run EH 6N30pi in my preamp because there's no alternative there). So if I do any tube rolling in the BHSE it will be for British Mullard vs. my current Holland EL34.