Two pots

It's been awhile since I last posted with Agon and my rig has changed somewhat. I will be recieving a Golden Voice tube intergrated in the near future and with only one input I'm forced to use my ASL pre for more sources. Both units have pots so how will I incorporate the two. The intergrated is only 12 watts but I don't anything about it's gain potenial. My ASL is a 12au7 piece with plenty of gain but I don't want to overdrive the units. I'm sure this post has been answered at some point but I appreciate any help in this matter. Enjoy the music!