Listening with headphones is an intimate sound experience and most enthusiasts use headphone amps and a good pair of headphones, like the ADL H118! 

The headphone amplifier determines the quality of the input sound to the headphones.

The ADL X1 is small, discreet yet highly specified with inputs supporting iOS digital up to 16bit/48kHz via an APPLE MFI certified USB cable for iPod, iPhone, iPad devices. The X1 also runs 24bits/192kHz SPDIF with high resolution files from PC via PC USB output. There is a 4-pin 3.5mm line level analog input and a 4-pin 3.5mm headphone output in the 12~600 ohm range. 3.5mm 4-pin mini jack input supports 3.5mm headset with microphone and remote control. 3.5mm TOSLINK optical output offers up to 24-bit/192kHz USB source signal. There is a convenient GND TRRS switch that makes it easy to switch from one 4-pin headphone to another.

Specs:

High-quality volume control and on/off switch (front)

3.5mm gold-plated input jack: analog line input (switched)

3.5mm gold-plated output connector #1: headphone or analog output

3.5mm gold-plated output connector #2: Headphone/analog output or 3.5mm optical output for SPDIF 24bits / 192kHz (Maximum)

4 layer gold plated printed circuit board with >1 ounce copper thickness

Gold-plated USB A socket for iPod / iPhone / iPad with 16-bit / 48 kHz resolution

Gold-plated mini-B USB connector for 24-bit/192 kHz PC conversion

Recharges via PC USB connection or AC/DC adapter (sold separately)

Attractive aluminum cover and ABS plastic body

Maximum headphone output at 1% THD at 1 KHz: 34 mW (12 ohms), 60 mW (16 ohms), 82 mW (32 ohms), 86 mW (56 ohms), 36 mW (300 ohms), 19 mW ( 600 ohms)

Channel separation: 60～64 dB (1KHz) 33 ohms at -50 dB / ≤ ±3 dB

Frequency characteristics: 20Hz ～ 20kHz (±0.5 dB)

Total Harmonic Distortion 0.033% (33 ohms), <0.02% (300 ohms), 0.0085% (600 ohms) at 1mW

Signal to Noise Ratio: 95.5 dB / 32 ohms, 98.1 dB / 56 ohms, 101.6 dB / 300 ohms, 102.1 dB / 600 ohms

Charging time approx: 4 ～ 5 hours (AC/DC 5V, 1.0 - 2.0A switching adapter - sold separately)

Charging time: about 7 hours (DC 5V - 0.5A USB bus power)

Music play time up to 7.5 hours when fully charged

Dimensions: 16.5 mm (Height) x 68 mm (Width) x 118 mm (Depth)

Weight: 147g approx.

Technical specifications:

24-bit/192kHz XMOS high-performance stream driver supports ASIO and asynchronous mode

Compatible with USB 2.0 Hi-Speed ​​(480 Mbit/s) supporting sample rates of 8 / 16 / 32 / 44.1 / 48 / 88.2 / 96 / 176.4 / 192 kHz

ESS-ES9023 high-performance 24-bit/192kHz DAC chip

Maxim MAX9724C Power IC, 1.8V Compatible Low RF Direct Drive Stereo Headphone Amplifier with Shutdown

Texas Instruments TI- LMV832 Dual 3.3 MHz CMOS Low Power Ruggedized with EMI OP AMP

Power supply 1: DC 5V 500mA ~ 2000mA

Power supply 2: DC 3.7V 2600mAh rechargeable lithium-ion battery

ADL X1 Compatible Devices

iPhone 7, iPhone 7 Plus, iPhone 6S, iPhone 6, iPhone 6Plus, iPhone5 (Lightning cable), iPhone4S, iPhone4, iPhone3GS

iPod touch 5th Gen (Lightning cable), iPod touch 4th Gen, iPod touch 3rd Gen, iPod nano 7th Gen (Lightning cable), iPod nano 6th Gen, iPod nano 5th Gen

iPod classic 160G (2009)

iPad mini, iPad 2, iPad 3rd generation

connectivity

USB mini-B socket for USB A output from PC and battery charging

USB A socket for iDevice output via APPLE MFI certified USB cable

Headphones and Analog Out 1 (Front) (4-pin) 3.5mm Headphone Jack and Analog Out

Headphones and analog output 2 (rear) (3-pin) 3.5mm headphone combo jack

Line input (4 pins): 3.5 mm minijack for analog input (switched)

Mini-optical connector output

Characteristic:

ESS-ES9023 DAC chip and high-performance 24-bit/192kHz USB XMOS

Digital inputs for iOS, PC

Excelent sound!

Digital / Digital Converter (3.5mm optical TOSLINK output)

Support ASIO and asynchronous mode

Goes anywhere, stacks easily

elegant appearance

low jitter

stacks easily

Fits in the palm of your hand

Enjoy music anywhere

Beautifully finished ABS plastic and aluminum housing

Does not consume battery power from the connected iDevice

Headphones and output can be connected to the home stereo system

Line input enhances the sound of portable analog audio sources

Front controls and indicators:

Headphone and Analog Out 1 (4-pin): 3.5mm headphone jack and analog out

Line input (4 pins): 3.5 mm switched minijack

Volume: rotary type variable resistor with on/off

Charge indicators: Three colors: RED, GREEN and ORANGE LED

RED indicates charge / GREEN indicates full charge / ORANGE indicates low charge

TRRS GND switch: switchable to match different types of 4-pin headphones (Sony or Apple)

Rear panel:

USB A socket: for APPLE MFI certification USB cable via iDevice for music

USB Mini-B socket: for USB cable through PC for music and for battery charging

Internal rechargeable battery type Li-ion DC3.7V 2600mAh

Headphone and analog output 2 (3-pin): 3.5 mm combo mini-jack and optical out mini-jack

Top panel LED indicator:

SB DAC (Digital Source - MAC or PC USB connection): Sample rates will be indicated according to the sample rate setting of the computer (44.1 / 48 / 88.2 / 96 / 176.4 / 192 kHz)

USB DAC (analog source - 3.5mm line-in connection): sample rates will be stated at 48kHz

iDevice digital connection: Sample rates will indicate (LED flashing) at 44.1 kHz (not 48 kHz) when connected with an Apple MFi approved USB cable

iDevice analog connection: Sample rates will indicate (LED on) at 44.1 kHz

Playing computer files using iTunes on Mac or PC: Sample rates will be listed based on computers

Sample rate setting (44.1 / 48 / 88.2 / 96 / 176.4 / 192 kHz)

Playing computer files using iTunes with Windows XP: sample rates cannot be set, so the X1 will indicate 44.1 kHz

Bottom panel:

Input selection: switchable between USB A socket or USB Mini-B socket

USB-A socket for iOS or USB miniB socket for PC

The switch must be reset after each selection, just turn the ADL X1 on and off