My previous post about the 300B tube amplifier build was a breakthrough. At least for myself. That was my first 300B amplifier build which if I remember, a decade ago, it will never across my mind to build such this expensive amplifier.
I learn a lot from that build and the 300B tube by its nature is direct-heated triode which I read everywhere saying that DHT will always have small hum present at the output, especially when pairing with the speaker sensitivity above 90 db.
My 300B amplifier built intended to drive a headphone. It is also can act as pre-amplifier. Small hum might be a problem for the listening enjoyment. Probably I should accept it.
But when the amplifier is done, the hum is worse than my expectation. It is loud and not at the acceptable level at all. The hum always presents at all time, even with the volume control fully closed.
I think more than a month and I tried to figure it out how to solve this issue. With the help of my friends, now this 300B amplifier is completely free of hum.
Yes, you are read it correctly. No hum at all, it is dead silent.
Only great music.
