Using Tube Head without power tube

[Bonzai_Musik]

Hello,
I have a B15 clone but I would like to use only its preamp section before attacking a more powerful SS amp.
It has as a preamp out, but would it be safe to run regularly without its power tube ( as to not damage the output transformer since it won't have a load)
Thanks

 

[MagnetoSound]

Measure the B+ voltage without the tubes in.

If it is still within the limits of the capacitor voltage ratings, there will be no smoke.