Sorry, more "Newbie" questions for y'all. I've just accquired my first ever amp without a headphone jack (Ampeg SVT Pro4) and I'd like to test it out at home. The problem is, I don't keep my cab in my apartment to plug it in to. Longer term, I'd like to be able to record through it at home too (i.e. without a speaker attached). So, the question is: Is it safe to power up the amp without a cab attached and just run the pre-amp output into a mixing desk? If it is ok to do this, are there any tips on how to adjust the various levels (i.e. gain, master and line out level) for optimum sound, or can I just experiment without of fear the amp melting? Thanks in advance for your comments.