One of the things our customers love to do is customize the sound of their Bottlehead Crack with new tubes. Audio enthusiasts call this tube rolling. We ship every kit with one 6080 and one 12AU7 (or equivalent tubes), but we encourage experimentation.
Over the years our Bottlehead Forum members have identified which tubes can be swapped in. Some of these tubes can be dropped in with no modifications while others require some work. Still others seem like they could be compatible with the Crack but aren't. Here's the list forum member Dr. Toobz has compiled:
Drop-in Equivalents
Tubes that work without modification to your Bottlehead Crack.
Input Tubes (Originally a 12AU7)
- 12AU7(A)(WA)
- ECC186
- ECC82
- ECC802(S)
- E8025
- E82CC
- CV4003
- CV4122
- CV491
- 5814(A)
- 6189(W)(WA)
- 6680 (WL6680)
- 6067
- 7489
- 7316
- 5963 (computer version of 12AU7)
Power/Output (Originally a 6080)
- 6AS7G
- 6H13C
- 5998
- 7236
- 6N13
Important note: the 6SN7 tube will not work in the Bottlehead Crack without an adapter. Sellers such as Garage1217 make adapters that will make a 6SN7 usable in the Crack. Bottlehead is not affiliated with Garage1217 and cannot guarantee their products, but forum members have had success with them in the past.
Pick up your own Bottlehead Crack, build it the way you want it, and roll in the tubes that create your specific sound.
What do I need to build my own Bottlehead kit?
What does a Bottlehead manual look like?