Wo-1 is a high-end pre-amp of Miyajima-Lab.
This amplifier is the unique design that the signal of the sound does not pass resistance.
This amplifier controls the volume by a change of gain not volume resistance.
The phonopermission input is 1,800mV.
It is approximately 5 times of the conventional high quality vacuum tube amplifier.
The output impedance is 1,900 Ω. (plate follower)
Watt of the output is approximately 10 times of the general amplifier.
Wo-1 has a current meter to fine-tune the balance of the vacuum tube.
A phono is 2 circuits, and this amplifier can change input impedance.