??tube="huh huh tube" Please see the video in the bottom how to pronounce..

What is it?

VFD(DM160) based high-resolution USB audio DAC. DAC is Asahi Kasei AK4490, with SA9023 controlled by 12 MHz TCXO. AK4490 is controlled through I2C, which command is published by ATMega88PA for its initialization. I guess you have no experience of VFD sound, indeed neither me just a few weeks ago. But its sound quality is something addictive. Wonderful sound is produced through VFD.

Why did you make it?

Actually I bought this VFD just for real indicator. I had a plan to make audio level meter using it but when I checked its data sheet, I got to know it is "direct-heated triode", as same as Nutube and 3A5 and, high-end 300B! I stopped "audio meter" plan and swapped it with Nutube and confirmed its wonderful sound quality. The sound quality is wonderful and something addictive. I've compared it with general subminiature tubes, but I found this VFD has better sound! Incredible!!!, and now way to avoid making amp with VFD!

What makes it special?

• DM160(IV-15) direct-heated triode based stereo high-resolution USB audio amplifier.

• Asahi Kasei AK4490 audio DAC controlled by the high precision TCXO.

• TI's precision differential-single end conversion IC (INA1650) is employed.

• AK4490 is controlled by the I2C command published by ATmega88PA, running Arduino boot loader.

• AK4490 is programmable through Arduino IDE. (Initial firmware is pre-loaded).

• USB bus power. Just plug USB cable is all we need to enjoy its wonderful sound! On-board voltage booster generating plate voltage (20V) for VFD.

VFD does not shine during operation, so I did not make "window" for it. (In the dark, you will see heater light.)