Go to the post office to get the package, don't look at the packaging is not delicate, but the outside is firmly wrapped with a layer of tape, which adds a lot of packaging foam and kraft paper. Later, I heard other friends say that this kind of packaging is the style of Brother Niu.
It was difficult to open the entire package, of course, with the help of my Swiss army knife. After a hard life and death, I looked breathlessly at the confetti and foam plastic on the floor. I just lit a cigarette and wanted to rest for a while. I heard a sigh of "Who did this?", And then I saw the old lady's face full of anger. . . . . .
After cleaning up the rubbish, it's the stuff inside. It's the protagonist we are here to play-the finished wrench of the single-ended amp:
The workmanship of the board is really unsaid. The single-ended amp amplifier circuit is a full-process double-faced silver-plated tin spray. The parallel power supply and headphone protection circuit use a single-sided wrench. It is strange, why not use both sides? It is estimated to reduce the manufacturing cost. After all, the cost of double-sided PCB is 2-4 times that of single-sided PCB.
I'm lazy. In fact, it's because I'm busy. Even the soldering iron that I rarely used has not been heated for a long time. Speaking of which, I will think of Brother Niu frowning and pointing at me and saying, you are too lazy to point fingers! ! ! !
Fortunately, Brother Niu â€™s finger is not pointing to the sky, nor the middle finger, so I can easily understand the meaning of the other person â€™s finger until a sunny day more than a month ago. My HD-600 pushes the ecstasy, I seem to have achieved it **
why? I didn't understand it either, until 14:30 when the mobile phone alarm sounded, I suddenly understood it (Daydream)
So, picked up my beloved soldering iron, soldered the Niu brother's circuit board.
It's not practical for me to weld. Brother Niu welded it to me, but still pretend to heat up the iron, open the dust-proof multimeter, light a cigarette, and enjoy the fun of the earth gun welding machine.
I have to take a look at the solder joints on the spanner. It seems that Brother Niu â€™s soldering iron is indeed better than mine. Each solder joint is the same. There is not much or no tin. The same makes me envious, it is estimated that the hands that have not welded tens of thousands of solder joints are good and such beautiful solder joints. At least it should be a foreign iron. Later, I heard that it was soldered with an ordinary soldering iron of 3 yuan per pair, which made me depressed for a long time.
Hey, think about it, the laziness of other people will make people understand the meaning. The single-ended soldered is lazy even if it is installed. I â€™m sorry people are not actually lazy, but I do nâ€™t know anything about circuits.
Even a resistor wants to ask how to divide the positive and negative poles. I can imagine my degree of idiot to the circuit. . . . . . Pain ING
The set of boards sent to me by Niu is a signature board. He personally designed, planned, constructed, commissioned, and handed it to the postman MM, and entrusted to him that he must send it to E Road. in!
Think about the future Shi Dujian (Marantz's chief engineer) sending me something, bliss ING
After the overjoy, I have to install the machine. First, I have to prepare the following basic things:
After buying two transformers, JS said that it was the United Kingdom. After the power was turned on, there was no symptom of Niu Ge â€™s multi-function transformer. The toroidal transformer outputs two sets of positive and negative 18V for single-ended use, nominal PRI: 120V + 120V, SEC: 18V + 18V, RATINC: 100VA
The E type is for the protection circuit. The voltage is 12V. I wo nâ€™t say much. I spent a total of 50 cases on the case of a CD player. It â€™s better to say one than the case of the CD player. Iron sheet, completely emptied the internal organs of the machine, including removing the panel, leaving only the power switch, this thing is really good to use. I also found a 6MM copper plate and asked a friend to process it and drill a few holes, even if it was a single-ended face.
First leave a hole in the case and take the empty board. I thought about the layout and made a gesture in the case. I really felt that I was an old gentleman looking at Feng Shui. I almost whispered with a compass on the side. Here you can send your children and grandchildren in the future "," The input end is facing forward, and you are in peach blossom. " . . . . . .
Think about the layout, the empty board is placed on the metal sheet, the metal sheet is marked according to the fixing screw position on the PCB, and then the transformer, input and output terminals, etc. are also drilled, and the following looks. Look:
The following is to install things. First install two transformers and power supply. When installing the power supply, there is an episode. The voltage is only about 10V, and the old tune is not high. Brother Niu asked me to replace the original R11 and R12 with a 2K resistor, which was replaced at that time. I don't know why I took two 680Î© ones and replaced them. As a result, the voltage can reach about 19.5V, but it is very unstable. It is 19.5V when it is turned on. It drops 0.5V every five minutes and is normal after 20 minutes. After half an hour, the measured voltage is 17.5V. The radiator is hot and the hand is basically Can't hold it.
At first, Niu said that if the parallel power supply circuit is not connected to the load, the power will be consumed by the two radiators. After connecting the single-ended amp as the load, the radiator will not have the function of fried eggs.
Preferably, I adjusted the voltage to:
After that, try the protection circuit. The relay closes automatically about 12 seconds after the power is turned on. If you want to hurry, change the capacity of the schematic diagram C4 to a smaller one. The PCB board needs to be changed to C5, the PCB board. The above is not the same as the schematic. I feel that there is a delay of 3 seconds. When there is time in the future, you must replace this capacitor, otherwise I am sorry for my personality.
Take a look at the small and exquisite protection circuit and small relay close-up:
Next, I started to install the amplifier circuit board. When the single-end came, it was already debugged. It stands to reason that you do nâ€™t need to look at it directly. But I still ca nâ€™t help but look at it. I appreciate the skills of Niu Niu. The people's attention is the two free 2.7uf RIFA420 series capacitors, but when I looked at it, I suddenly saw a lot of vacancies on the board, and I whispered in my heart. What's going on? C2, C3, C4, C5 are not soldered. I am a circuit idiot. What happens to a few more components and a few more components, call and ask immediately
"It's okay, you can just go directly, I'll debug all of them." Simple, brief, in general, he won't tell me that a certain component plays a certain role in a certain place, it is his style, he knew me With the HD-600, this headset has more low-frequency and some high-frequency staining, because I said that I am a circuit idiot. The degree of idiot is proportional to the degree of laziness. Although the circuit is debugged, but I I want to go through thousands of kilometers of running, maybe there is a problem. It may be possible to adjust the midpoint voltage first. The VR1 is adjusted. In fact, it was originally adjusted. In my case, I ca nâ€™t help but use a small screwdriver to go around. After a few moves, the result is this:
Next is to adjust the current. In order to test the current, I bought an alligator clip. How can I know there is no place to clip the first test point does not leave a test pad on the PCB, and the resistance of the 1 / 4W resistor, use The resistance is 1W, so there is no way to clamp the pin. I hope to leave two more solder holes next time so that it can be easily debugged. Later, I replaced the 3.3 ohm resistor with two 2.2 ohm resistors. I purposely left the pin a bit on the resistor, which means that the pin was bent up first and then down to make it n-type, so that it can be clamped. Holding the pin is the same as adjusting the potentiometer. Clamp the pin first, then turn on the power, and adjust VR2. Just remember to be careful not to loosen the clip when clamping, it is easy to cause a short circuit. 320MV / 2.2Î© = 145MA, I heard that the sound at this position is best to be single-ended and basically debugged here.
Below are some of the fragmented peripherals installed. Do nâ€™t look at the fact that these fragmented peripherals are simple to install, sometimes annoying enough, especially for some lazy people. It takes me two or three nights to do some wiring alone. Teflon is used for all the internal connections. Teflon is very troublesome to peel. First of all, I scrapped my two lighters because I couldn't burn them. You can only use a saber to cut slowly. Fortunately, the saber is enough. Then, it is more troublesome to put a layer of heat shrinkable tubing on all the wire ends. Before and after, I tried many methods. Finally, I input a little ground, so the noise is compared. It is relatively simple to make it small, but it is even better, even the input is not grounded, so there is no obvious noise when the volume is turned up at the maximum, but even if the hand does not touch the chassis, the audio input must also be turned on. There will be no small sound when the hand is touched or the sound source input is short open!
There are two other noise issues worth discussing, that is, the noise is extremely serious when the hand approaches the input capacitor!
There is extremely high-frequency noise before and after the relay is closed, that is, when the single-ended is not connected (this is estimated to be external interference)
Install the input terminal and the headphone output. Even if the project is over, it can be delivered and used. Look at the nude photos:
I started to listen to it. At first, I used a walkman radio. I first tried to check if there is any sound. Of course, I did nâ€™t connect it directly to the HD600. I used ordinary headphones that I usually use on my computer. Lights up, the relay closes after 12 seconds, the sound comes out, there is no obvious distortion, first put it in the test, to see if the component is abnormal, the single-ended board has a temperature of about 60 degrees in half an hour, and almost the same in one hour. , The conclusion is normal!
Just use the radio as a sound source to practice for one day. Tomorrow will be 600. The next day, I will connect to the sound sources Pioneer DV-S737 and Sennheiser HD-600. Hehe finally felt the voice performance. Hey, in fact, I will It's subjective. For many reasons, the most important thing is that I'm used to listening to the sound on the AC97 integrated sound card. This is certainly not fair for comparison.
So I have to talk about the shortcomings first. I have little sense of quantity. Of course, I am used to the true feelings of MP3. Because the computer MP3 has a balanced and always adjusted to V type, it will feel normal compared to the straight-through single-ended. This is unfair. Hey, hey.
Of course it is the feeling after just using it for more than ten hours. It is estimated that it will be different after a while.
The advantage is that it is very transparent, desorption force is also good, positioning is also possible, and it is inclined to lively sound. This is also shown by the small background noise. It is not used to listen to the guitar! ! ! Does he think this single-end is made for guitar? The guitar performance is really good! ! !
There is only one place for personal improvement to listen to percussion, that is, the low-frequency volume is relatively low, but the dynamic is not bottomed, and I am used to the feeling of rumbling, which gives me another fresh and hearty, full of rhythm! Especially when listening to The Magnificent Suite, there is a feeling of deterring performance of strings and vocals. I will not say it for the time being, because the skills are not enough, and there are not many softwares in this area. I am afraid to make mistakes. In tossing, just to get my ears to get used to the sound of single-ended, or to get used to my voice, and always let the single-ended milk come out, but he said that single-ended only out of the clear spring. In the end, he tossed me to the blacklist. Look, this is his after-sales service. I am always thinking about changing the capacitor, the tube, the current, and the voltage. . . .
Hey, he didn't give me a sentence until the end. You can use Qingquan to brew milk powder to see how it is. My earphones are enough milk powder. . . . . How is it. . . Sound source Hey, wait for us to have money ~~~ Buy Nestle milk powder CD as the sound source!
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