I have that same preamp. I like vintage Ge 12ax7WA/6201 tubes. You should be able to get a matched pair from any reputable seller on ebay for less than 50 bucks!
The GE JG-12AT7WA vintage tube is a rugged, American-made workhorse produced for the U.S. military and used for computers and targeting equipment. This tube is usually very low in microphonics due to its rugged construction. The GE JG-12AT7WA had to work well under arduous conditions and was made with solid support rods and short, gray plates.
The GE JG-12AT7WA vintage tube is a rugged, American-made workhorse produced for the U.S. military and used for computers and targeting equipment. This tube is usually very low in microphonics due to its rugged construction. The GE JG-12AT7WA had to work well under arduous conditions and was made with solid support rods and short, gray plates.