MODERATOR: Please move to a tube/Crack thread.
My Crack is still in the mail, so I’ve been researching build and setup options. I expect to spend up to a month or two on the build before using it (wood finishing can be painfully slow with dry times).
Stream of consciousness here:
One of the Crack’s standard tubes is a 12AU7. These are “a dime a dozen” and I have about a dozen that I bought for a prior amp. With that amp, the most obvious changes were associated with the metal mass inside the tube. They come in “short plate” and “long plate” versions. The short ones were routinely brighter while the long ones were bassy. The factory tube and my first aftermarket tube were both short plate, so there wasn’t much change and I wasn’t impressed. I restarted tube rolling later with different internal designs.
Beyond tone, some tubes are very resonant/harmonic/fuzzy while others are cleaner. This property varies even within specimens of the same model/brand. Some vintage tubes sound like cr*p too. Worn out, flat, and lifeless, with weird whines and artifacts. YMMV, but don’t be shocked in the vintage market. Don’t trust “New Old Stock” or NOS marketing either, as sellers sometimes don’t understand that Not Used By Me <> New. The inventory of old tubes is dwindling too.
I’ve never owned or rolled a Crack, so…we’ll see… [Insert body anatomy jokes HERE.]