The 300B provides truly appropriate power and voltage swing for headphones and makes a remarkable

The 300B provides truly appropriate power and voltage swing for headphones and makes a remarkable line driver. The impedances are not too low and the power requirements are not too high, it is ideal for this kind of tube in a single-ended configuration.

Manley combine the historic 300B with another classic, the large octal based 6SL7GT, for the input stage- all triodes running in pure Class A operation. To complement this 'retro' feel, Manley implemented vacuum tube rectification (two 5AR4's) and regulation (two OD3's) in the power supply along with plenty of capacity. Manley also developed an additional (and innovative) ripple rejection circuit to filter out power supply noise making this an incredibly low-noise preamplifier- especially critical for headphone users.