Improving the bass of the valve preamplifier

摘要

Your valve preamplifier in the January 2016 issue is a great project and I'm interested in building one to try the "valve sound" for myself. I've tried many op amp and discrete semiconductor preamp designs over the years and have tended to prefer the sound of simpler designs based around a complementary-feedback pair of bipolar transistors or discrete op amp types over the ultra-low THD op amp versions, so I expect to like the valves.