The Difference Between B4 and B4-X
B4-X is a dual-mono balanced version. Its left and right channel are amplified by independent components, and power supply, tubes, and op amp are all independent and symmetric. So the degree of sound separation is higher than B4.
B4-X adopts 2 groups of independent power supply(+12V and -12V) for 2 op amps, less mutual effects and can drive 300Ω headphones.
The circuit adopts dual op amp parallel output, with higher output power.
B4-X has 3.5mm and 2.5mm 2 kinds of output interface, suitable for most of balanced and standard headphones.
Mini Size and Unique Design
Built-in tube makes you have a tube amplifier which can be held by one hand, convenient to carry and can enjoy HiFi music everywhere. Full, delicate and soft sound: warmer than transistors, independent op amp and power supply inhance the SNR and degree of separation, less interplay and higher sound quality.
With Built-in Battery Protection Circuit
Battery lets your listening feast without time limitation. It can't be turned on during charging and will power off automatically after fully charged, and charger LED will turn to green.
High-end Making Material and Craft
Using gold-plated socket, original nichicon electrolytic capacitor, original DALE resistors and precision ring resistance.