Portable rechargeable dual tube bile duct amp B4, mobile phone, headphone amplifier

Type:Logic ICs
Condition:New
Special reminder: According to many old customers, after using the machine for a period of time, there are some opportunities for channel imbalance, or a certain channel has noise, distortion phenomenon. This is because the machine is using a new tube. So in After the boot, there is a change in the internal resistance of the individual tubes. This causes the above phenomenon. The solution is to re-match by adjusting the adjustable resistors inside the machine. After re-adjusting, it can be used for a long time. Previous update point. Update points: Charging is changed from the original USB charger to 12.6V direct charge. Mainly to solve the bottom noise. The previous booster board was difficult to make without noise. Therefore, it can only be changed to 12V battery direct supply. The original USB is not convenient for charging. But for the sound quality to improve. This is worth it. Because it can be fully charged, it can take 4-5 hours. It is also enough to go out to listen to music, do not need to listen to it with USB. The other is to cancel the charging and power LEDs inside the machine. In this case. When the machine is working, only the two tubes inside are illuminated. Better than before. Of course, the LEDs in the PCB are reserved for the power LEDs. If you have the ability to operate, you can add them yourself. This latest model, the tube is 5899, currently all new inventory Raytheon tube, origin: the United States, the number is not much, the speed is not much. 1, the casing is a wire drawing process, the casing has a transparent acrylic baffle. Because the temperature of the tube is about 80 degrees. 2, electronic components, now with DALE resistors, ALPS potentiometer, all aluminum volume knob. 3, the op amp is imported NE5532 classic IC, of ??course, you can also freely upgrade your favorite op amp. Increase playfulness. 4. Charge is 12.6V charger. Full of about 2 hours, working time 4-5 hours, 5, each channel uses a tube to process the signal, the sound aspect. Self-feeling is warmer than B1. I don't know if there is any psychological factor. This requires the identification of the friend himself. About the working mode of the op amp, the most used Simple amplifying circuit, the simplest peripheral circuit, in addition to the necessary resistance and two coupled output capacitors, there is no other redundant components, after all, in my opinion, the simplest circuit sound is smaller, so that Keeping the sound through the tube is the most primitive, closest to the tube sound, which may be warm. This unit includes an amp (black.), 1 built-in 1000mA lithium battery (working time is about 4-5 hours), (full power is about 2 hours), and 2 straps are bundled (for bundling with mobile phones). A 15 CM 3.5 male pair is connected. Used to connect mobile phones and amps, Some common parameters: It is recommended to push the sound quality of 30~100 ohm headphones. Pure.