Description

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