They are not 300b powered, but Audio Mirror 45w SET mono blocks may be worth a look. Really like mine. No problem driving my 86db speakers. They sound great.
High powered single end 300b recommendations
I would like to try a se 300b integrated to find out what the famed sound is like. However, at 86db, my Harbeth S-HL5 are not very efficient. They need more like 25-30W to drive them.
Any recommendations on an 300b amp that will work with these speakers?