Back to Yamamoto

Yamamoto Sound Craft : Vacuum tube Headphone amplifier HA-03


It is the optimal amplifier for a direction to use both headphone and a speaker.
HA-03 is the unique amplifier which designed headphone, of course aiming at the amplifier which can enjoy itself by the best sound quality also with the speaker.
The amplifier which can generally enjoy both headphone and a speaker in the optimal state is made difficult.
In this machine, I conquered the difficulty by using the highly efficient vacuum tube C3m with one-step composition.
As for vacuum tube amplifier, the simplicity of the composition appears in sound.
In the case of this machine, the charm which simplifies the composition to a limit and the vacuum tube has been pulled out to the maximum extent.
Since it is simple, freshness sound and music can be enjoyed.

Available on backorder

SKU: Yamamoto HA-03 Categories: , Tags: , ,




The amplification circuit of this machine is very simple.
Only one step is used by considering the pentode C3m of the vintage vacuum tube by German Siemens as pentode connection, and the moderate amplification rate and the highest quality are pulled out.
A negative return was not used for the circuit but the simplest and natural non-feedback system is adopted.
If a negative return is used, performance will become good, but sound becomes unnatural in many cases.
The number of the parts to pass is reduced to a limit, and degradation of sound is suppressed to the minimum.
The screen grid circuit and the plate circuit were used as another power supply in it, and the output as big as about 1W has been obtained by speaker load by constant-voltage-sizing a screen grid circuit.

Additional information

Weight 3.5 kg
Dimensions 0.325 × 0.150 × 0.125 cm