By adding deeper negative feedback and adjusting bias(offset) current accordingly. You will then jeopardise stability of the amplifier for good and will need lots of trial-errors to get it stable. Highly UNrecommended procedure.
Thanks for the response, Marakanetz. I found the info I was looking for, and there is no need for me to worry about impedence level. The ratios will be fine. Now I can pursue my tube preamp. Thanks again.