Tanzan Akira previewed headphone amplifier of the Fire Stone Audio "Fireye Series"

Fireye HD　

In the finest model of "Fireye" series, 

smartphone size headphone amplifier classified in relatively large grade.

HD(High Difinition) named comes from emphasizing 

the basic function such as analog input and headphone output, 

and having the confidence in particular to the quality of sound. 

Charging battery, Lithium-ion battery that allows for 8 hours continuous drive, 

mounted with input gain switching circuit and bass boost circuit.

Alpha

Fireye DA

Headphone amplifier with built-in USB DAC 

at a size of about half of "FireyeHD", but also suitable to carry. 

Power supply, compatible with USB bus power. 

Characterized by such a multi-function that in addition 

to USBDAC headphone amplifier 24bit/96kHz, 

supports a mini-jack line output of 3.5mm, 

can also be used as a DA converter, 

and can also be used as DDC with S / PDIF (optical terminal output).

Fireye HA

Headphone amplifier, cheap model at a size of about half of the best grade "FireyeHD". 

Equipped with lithium-ion battery that allows 12 hours continuous driving 

and input gain switching circuit and a bus boost circuit,

 while limiting the thickness to 16 mm. 

In the own analog circuit, in pursuit of sound quality, 

incorporated with a function to limit POP noise when generated in ON / OFF, 

and function to switch the input gain(High / Low).