AD00032 Current Feedback Portable Headphone Amplifier (Assembled)

The only reason for choosing the current feedback method

"Current feedback method" may not sound familiar to general listeners who are not very familiar with Hi-Fi audio.

However, for those who are deeply familiar with audio, the current feedback system, which can efficiently drive the speaker from bass to treble, has been chosen by users as an amplifier for experts.

Bit Trade One uses a current feedback method that faithfully reproduces the original frequency characteristics of headphones, making the amplifier itself portable for portable audio devices such as iPhones and smartphones.

You can easily enjoy high impedance type Hi-Fi audio headphones even when you go out.

Efficient drive from bass to treble, unique current feedback system " LIIE technology installed "

As you know, the nominal impedance in headphones only shows the lowest impedance.

When operating with a conventional voltage-driven amplifier, there is a tendency for the impedance to rise between bass and treble, resulting in a tendency not to produce the intended output.

LIIE technology, which is Bit Trade One's proud current feedback method, senses the current flowing through the headphones with a sensing resistor and feeds it back, thereby controlling the "power" applied to the headphones to a constant level and eliminating the effects of impedance fluctuations. For this reason, it is not affected by impedance fluctuations in headphones, and it drives firmly and efficiently from bass to treble. It delivers a rich, dynamic sound that you won't believe is your headphones.

* Utility model registered

[Output Capacitor-less Technology] contributes to the improvement of bass characteristics

This headphone amplifier not only amplifies the original signal of the amplifier, but also eliminates the coupling capacitor that causes unpleasant pop noise from the power amplifier output circuit.
Pop noise is reduced by this, and also the low-pitched sound characteristic is greatly improved.

Originally, this product uses 4 commercially available AAA batteries to remove the coupling capacitor required for the circuit,
By using this at +-3V, it can be driven using both positive and negative voltages.
By using the ground level as a reference for output, it is possible to prevent signal attenuation in the bass range caused by the output coupling capacitor and output rich bass.

Pursuing the best matching with headphones with customization function

By using the 6 types of adjustment resistors attached to the product, it is possible to support headphones with a nominal impedance of 600Ω.

Six types of adjustment resistors are available to match the headphones you are using. By replacing the resistance, it is possible to set the user side so that the performance of the headphones you have can be maximized Of course, the resistance can be easily replaced with a socket type.

There is a reason for adopting AAA batteries. Long-lasting long-run specifications

By using 4 AAA batteries, it can be used for about 30 days with about 5 hours of use per day.
In addition, it is expected that the built-in lithium-ion batteries used in many portable headphone amplifiers will steadily decrease in supply capacity over the years of use, eventually becoming unusable.
Under such circumstances, this product uses AAA batteries.
By replacing the battery itself, not only the power supply but also the product itself has a long life cycle specification.

Upgraded the kit version by adopting audio grade capacitors

Compared to the popular current feedback type portable headphone amplifier kit, the resistors and capacitors used have been upgraded! We have carefully selected components to create the best sound quality.

The resistor used is a 1% error compatible product, the capacitor has been changed to an audio grade, and the front panel knurled screw, which required a screwdriver in the kit version, eliminates the need for a screwdriver that was required when replacing the battery.

Product Specifications

Product name: Current feedback type portable headphone amplifier

Product model number: AD00032

Correspondence impedance: 16Ω - 600Ω

Input/output terminal: 3.5Φ stereo minijack

Maximum output power: 50mW + 50mW (at 16Ω)

Frequency response: 20Hz ~ 20KHz

Adjustment resistance: 2Ω/3.9Ω/8.2Ω/15Ω/33Ω/62Ω

Power supply: 4 AAA batteries (batteries sold separately)

Usable time: about 150 hours (can be used for 30 days if used for 5 hours a day)

Size: W70×D114×H20mm (excluding volume)

Body weight: 147g (not including batteries)

Contents: 3.5Φ stereo cable (male/male), manual, adjustment resistor 6 sets

Warranty period: 1 year from purchase

JAN code: 4560196900387