@infection I mentioned earlier about how you can't just buy tubes off the shelf and expect them to work in a high performance circuit.
Lew's advice is good- those tubes are in there for a reason. This isn't saying that you can't do better- you can, just expect that when you buy a hot-shot tube be it boutique or NOS, that it may not be as quiet or low microphonics as you expected and you may have to return it and try again.
We buy tubes 100 at a time, so we have more examples to go through to find the tubes in the box that sound right. I'm sure that's what Keith is doing too.
Lew's advice is good- those tubes are in there for a reason. This isn't saying that you can't do better- you can, just expect that when you buy a hot-shot tube be it boutique or NOS, that it may not be as quiet or low microphonics as you expected and you may have to return it and try again.
We buy tubes 100 at a time, so we have more examples to go through to find the tubes in the box that sound right. I'm sure that's what Keith is doing too.