Bear portable rechargeable dual electronic tube bile duct amp B4 mobile phone balanced version headphone amplifier | Электроника

Bear portable rechargeable dual electronic tube bile duct amp B4 mobile phone balanced version headphone amplifier | Электроника

Special reminder: According to many old customers, after using this unit for a period of time, there may be some chances that the channel is unbalanced, or there is noise or distortion in a certain channel. This is because the unit is a brand new tube. So in After the boiler is turned on, the internal resistance of individual tubes will change. This causes the above phenomenon. The solution is to re-match by adjusting the adjustable resistance in the machine. After re-adjustment, it can generally be used for a long time. Specific methods You can contact customer service

Fever, Teflon 3.5 audio pair recording cable, amp dedicated 15CM

In addition: the power plug specifications of each country are different, you can note the plug specifications, of course we will also check it by ourselves

For some buyers with strong hands-on ability, you can also buy one more or a pair of tubes for spare.

A note about the newly added balanced version B4-X:

1. The type of this balanced version belongs to the Dual-Mono balanced version. In short, the left and right channels are amplified by independent components. Including the power supply, the tube, and the op amp. They are all independent and symmetrical. So the sound separation is better than The B4 standard version is higher. Another point is different from the standard version. The balanced version uses a dual-voltage power supply, +12V, -12V, so the output power is higher (the standard version is a single power supply 12V). The balanced version can be pushed up to 300 ohm headphones. In terms of use time, the two are about the same. Both are about 4 hours. In terms of balanced output interfaces, there are two standards of 3.5 and 2.5. Suitable for general balanced headphones and standard headphones.

Update points: The charging is changed from the original USB charging to 12.6V direct charging. Mainly to solve the bottom noise. The previous booster board is difficult to make without bottom noise. So it can only be changed to 12V battery direct supply. Charging is not as convenient as USB. But to improve the sound quality. This is worth it. Because it can be fully charged for 4-5 hours. It is also sufficient for the needs of listening to music outside, without the need to use USB to listen and charge.

The other is to cancel the charging and power LED inside the machine. In this case. When the machine is working, only the two tubes inside emit light. It looks better than before. Of course, there is still a light position for the power LED in the PCB. If you have the ability to operate, you can add it yourself.

1. The casing is made of wire drawing process, and the casing has a transparent acrylic baffle. Because the temperature of the tube is about 80 degrees when it is working.

2, Electronic components, now use DALE resistors, ALPS potentiometers, and all-aluminum volume knobs.

3. The op amp is imported NE5532 classic IC, of course, you can also freely upgrade your favorite op amp. Add fun.

4. Charging is a 12.6V charger. It takes about 2 hours to fill, 4-5 hours working time,

5. Each channel uses an electronic tube to process the signal. In terms of sound, I feel warmer than B1. I don’t know if there are any psychological factors. This point needs to be identified by the listener. Regarding the working method of the op amp, the most used The simple amplifying circuit has the simplest peripheral circuit. Except for the necessary resistors and two coupled output capacitors, there are no other redundant components. After all, in my opinion, the simplest circuit has a smaller sound effect, so that it can. The signal after keeping the sound passing through the tube is the most original and the closest to the tube sound.This may be a warm sound.

This machine includes an amp (black.), a built-in 1000mA lithium battery (working time is about 4-5 hours,) (full charge is about 2 hours), and 2 straps (used to be bundled with a mobile phone), 15CM 3.5 male to male connection. Used to connect mobile phones and amps,

Some common parameters:

It is recommended to push 30~100 ohm headphones with good sound quality and purity.

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Here is the balanced version.

The silver picture above is an old version, which has been discontinued