Only the 12AX7 are preamp tube, the 12AT7 are driver tube.
If driver tube are not installed, the power amp will not work.
Integrated tube amp as amp only
My Jolida 1000rc has a main in so it can absolutely be used as an amp only. My question is can I take out the preamp tubes and move them to my tube preamp. They use the same 4 tubes. Turn on the Jolida with the pre tubes removed while using it as an amp only? Is it safe? Or do I need to order another 4 preamp tubes.