ADV Fully Balanced Tube Headphone Amplifier Portable Tube Headphone Amp w/ Type-C USB Charging Cable

ADV Fully Balanced Tube Headphone Amplifier Portable Tube Headphone Amp w/ Type-C USB Charging Cable

Circuit:
- The circuit is designed for class A loop-free feedback, pursuing the most natural and unfettered sound performance.
- It adopts dual triode tube common-negative voltage gain, op amp buf stage buffer, and triode current output.
- The output of the circuit is a direct even output, which removes the output coupling of the large-capacity electrolytic capacitor to avoid the coloring of the sound quality and excessive artificial modification by the electrolytic capacitor. In addition, the sound quality is more pure, transparent and natural.

Features:
- Its acoustic-to-noise ratio is quite good, reaching a level comparable to that of traditional pure integrated IC portable headphone amplifiers
- The supply voltage of the tube circuit of this machine is 30V. Under the premise of satisfying the linear index, a relatively high slew is obtained
- Op amp supply voltage ±12V
- Mid and high frequencies sound is transparent, and low frequency sound is powerful. Good resolution and high dynamic range. Class A sound is charming, has a strong musical flavor, and has excellent performance with low distortion and wide frequency response. The vocals are warm and detailed

Components:
- Internal resistance: original resistor for VISHAY and original resistor for KOA. Low temperature drift 0.5%
- Volume control potentiometer
- Input coupling capacitor: Original electrodeless speaker capacitor for Arcotronics
- Imported power supply filter capacitor
- Two imported double tripolar tubes. The tubes has low internal resistance and long service life. Their sound is clear and transparent, delicate and round, and the music is rich
- Cost-effective LM4562 op amp: The op amp is pluggable. Users can upgrade their favorite op amp ICs to improve the performance of the device for better sound quality
- Imported current output tube

Basic Parameters:
Functions:
- Working mode 1: single-ended class A mode input and output (3.5 headphone jack)
- Working mode 2: Class A parallel mode input and output (3.5 headphone jack)
- Working mode 3: Class A balanced mode input and output (4.4 headphone jack)

Endurance Time:
1. Single-ended class A mode: about 8-9 hours
2. Class A parallel mode: about 4.5 hours
3. Class A balance mode: about 4.5 hours

Other Parameters:
- 9600mAh built-in lithium battery: It is recommended to use a charging adapter no less than 5V 2.5A. It takes about 4.5 hours to fully charge. It can be used while charging
- Support power bank to provide 5V 2A charging output
- Frequency response range: 20HZ-42KHZ
- THD: 0.015% 1khz
- SNR: 95dB
- Output power: about 900mw (32Ω) in single-ended Class A output mode; about 1350mW (32Ω) for class A parallel mode output; about 1620mw (32Ω) for class A balanced mode output
- Output load range: 16Ω / 400Ω
- Size: 120 x 76 x 29mm/4.7 x 3 x 1.1" (LxWxH)

Package Included:
- 1 x Main unit
- 1 x USB charging cable

Attention:
- Tubes are high-temperature devices. At an indoor temperature of 30°C, the case temperature of headphone amp is about 56°C when working.

After-sales Warranty:
1. When there is no man-made damage or no disassembly of the product, our store and the buyer bear half of the costs (cost of sending the product back to China + tariff) respectively, and the maintenance fee is waived.
2. When its fragile label is damaged (i.e. the device has been disassembled), the buyer needs to bear the following costs: cost of sending the product back to China + tariff + maintenance fee.
3. Tubes are consumables. The warranty period of the tubes is three months. After users disassemble the device, the tubes are not covered by the warranty.

Panel:

Easy to Use:
1. Single-ended mode: Power on. After a few seconds, the two-channel indicator will light up. Signal is connected to the 3.5 input port, and your headphones are connected to the 3.5 output port.
2. Parallel mode: Power on. Toggle the channel switch BAL/A//. After a few seconds, the quad-channel indicator will light up. The mode is switched to the A// position. Signal is connected to the 3.5 input port, and your headphone is connected to the 3.5 output port.
3. Balanced Mode: Power on. Toggle the channel switch BAL/A//. After a few seconds, the quad-channel indicator will light up. The mode is switched to the BAL position. Signal is connected to the 4.4 input port, and your headphone is connected to the 4.4 output port.