VHT Pitbull Model C-5084-T

Model C-5084-T serial number DE970135
Question regarding my C-5084-T. Is it ok to run this amp with the power tubes removed and no speaker connected? I want to use the preamp section, go out the effects loop and into a separate stereo tube amp because I use stereo effects. If not, is it ok to run the amp with power tubes in and speaker connected but nothing coming back in on the effects loop?