Diy Headamp

Sắp giáng sinh rồi, tết cũng đến gần...
Ngồi rảnh rỗi nghĩ linh tinh!
Thấy cũng vui trở lại.

Hôm nay ngồi nộp 2 CV bằng mạng của công ty. Biết là bọn IS nó biết và sẽ báo cho sếp nhưng chả sao. Bình thường mà.

He he, tự nhiên nghĩ mình giống Mai An Tiêm, ngày ngày ném những quả dưa hấu xuống biển ... Hi hi ^^

Chả biết quả dưa mình sẽ dạt về đâu. Cũng như việc viết blog thế này, k biết có ai đọc được những gì mình viết.... ^^

Vui vui ^^

Lại tự sướng lúc 1/2 đêm !

Mình đã bước vào bước ngoặt lớn trong cuộc đời. Một bước ngoặt không như mình mong đợi. Mọi thứ mình chờ đợi ở chỗ làm đều không như mình nghĩ. Samsung không phải là con đường màu hồng. Tất cả những gì mình nhận được là sự mệt mỏi trong suy nghĩ, chán nản khi công việc. Những lần đến công ti giống như là sự lê lết trong suy nghĩ, uể oải trên cơ thể.
Dẫu biết đi làm là khổ, nhưng thực sự phải được cho mình 1 chút j?
Kinh nghiệm ư? Chắc là k.
Tiền ? Càng không
Thế mình dc cái j đây.

Thực sự mình là 1 người tham vọng. Sai lầm của mình là sự nghiệp bắt đầu từ samsung. Không phải là nơi cho sự cố gắng, cống hiến. Ở đây chỉ có overtime ...

Thôi! Chả than thân làm j nữa.
Đành chấp nhận, chờ ngày ra đi ...

Sản phẩm tiếp theo đây :
Hoàn thành cách đây mấy tháng nhưng ...

Why DIY?

Contrary to popular belief, the main reason for DIY is not (or should not be) about saving money. While this is possible in many cases (and especially against 'top of the line' commercial products), there are other, far better reasons to do it yourself.

The main one is knowledge, new skills, and the enormous feeling of satisfaction that comes from building your own equipment. This is worth far more than money. For younger people, the skills learned will be invaluable as you progress through life, and once started, you should continue to strive for making it yourself wherever possible.

Each and every new skill you learn enables the learning processes to be 'exercised', making it easier to learn other new things that come your way.

Alvin Toffler (the author of Future Shock) wrote:- "The illiterate of the 21st century will not be those who cannot read and write, but those who cannot learn, unlearn, and relearn."

This is pretty much an absolute these days, and we hear stories every day about perfectly good people who simply cannot get a new job after having been 'retrenched' (or whatever stupid term the 'human resources' people come up with next). As an aside, I object to being considered a 'resource' for the corporate cretins to use, abuse and dispose of as they see fit.

The skills you learn building an electronics project (especially audio) extend far beyond soldering a few components into a printed circuit board. You must source the components, working your way through a minefield of technical data to figure out if the part you think is right is actually right. Understanding the components is a key requirement for understanding electronics.

You will probably need to brush up on your maths - all analogue electronics requires mathematics if you want to understand what is going on. The greater your understanding, the more you have learned in the process. These are not trivial skills, but thankfully, they usually sneak up on you. Before you realise it, you have been working with formulae that a few years ago you would have sneered at, thinking that such things are only for boffins or those really weird guys you recall from school.

Then there is the case to house everything. You will need to learn how to perform basic metalworking skills. Drilling, tapping threads, filing and finishing a case are all tasks that need to be done to complete your masterpiece. These are all skills that may just come in very handy later on.

Should you be making loudspeakers, then you will learn about acoustics. You will also learn woodworking skills, veneering, and using tools that you may never have even known existed had you not ventured into one of the most absorbing and satisfying hobbies around.

Ok, that's fine for the younger generation(s), but what about us 'oldies'? We get all the same benefits, but in some cases, it is even possible to (almost) make up for a lifetime spent in an unrewarding job. As we get older, the new skills are less likely to be used for anything but the hobby, but that does not diminish the value of those skills one iota.

However, it's not all about learning, it's also about doing. Few people these days have a job where at the end of the day they can look at something they built. Indeed, in a great many cases, one comes home at the end of the day, knowing that one was busy all day with barely time for lunch, yet would be hard pressed to be able to say exactly what was achieved. What would have happened if what you did today wasn't done? Chances are, nothing would have happened at all - whatever it was you did simply wasn't done (if you follow the rather perverse logic in that last statement ).

Where is the satisfaction in that? There isn't any - it's a job, you get paid, so are able to pay your bills, buy food and live to do the same thing tomorrow.

When you build something, there is a sense of pride, of achievement - there is something to show for it, something tangible. No, it won't make up for a job you hate (or merely dislike), but at least you have created something. Having done it once, it becomes important to do it again, to be more ambitious, to push your boundaries.

Today, a small preamp. Tomorrow, a complete state of the art 5.1 sound system that you made from raw materials, lovingly finished, and now provides enjoyment that no store-bought system ever will.



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The Financial Side

(Advertising slogan ... 'Buy NOW and save!' Translation ... buy now and spend)

It has to be considered that no hobby is financially 'viable' as such. People who build model planes or railway layouts or knit jumpers don't do it to save (or make) money, they do it for enjoyment, for the love of creating (or re-creating) something.

For some, it is imagined that by using the DIY approach, they will save money. No, you won't (well, you might, but if you do, that's a bonus, not the reason). In general, you will spend money, and if you were to add in the tools that you buy to DIY, plus the book(s) that you figured you needed, plus the costs of the occasional mistake that destroyed an amplifier's output stage, plus a bit of this and a bit of that ... it all adds up.

No. You won't save money. After the first few projects are working and have become part of the furniture, then you realise the real benefits. The gain is just a bit too low - open up the case, change a resistor, and voila! Easy. Cheap. Try getting a major manufacturer to do that with a commercial product - even worse, take it back to the shop and ask them to increase the gain by 6dB ...

They won't know what you are talking about
They don't care what you are talking about
Strangely, they invite you to go away and urinate
Having built a pair of speakers and a preamp, you read an article on the Net that claims that biamping is almost magic! Well, you do have another amp lying about, but can you get everything else you need to try this for a sensible price from a shop? No. Can you make an electronic crossover yourself? Yes. This time, it will be cheaper than you can buy one for, because you already built your own preamp, you know what's in it, you can add the board to include a crossover. Your preamp and speakers will be out of service for a couple of days at most, and if you decide for whatever reason that you don't like it, you can change back. The total cost in real terms is peanuts.

More importantly though, the whole process is one of learning, experimentation and experience. These are all priceless - you can't buy them. By doing it yourself you can only improve yourself. If things go wrong, this is even better (believe it or not).

There is absolutely no doubt that few things are as discouraging as a DIY project that doesn't work. Despite that, there are few things more encouraging than (eventually) finding the problem and fixing it. Don't expect it to be easy, because it almost certainly won't be. Servicing and fault finding are special skills, and are almost impossible to teach (except perhaps for a particular product where common faults are known).

To track down a fault that exists in something that has never worked is particularly difficult, but it can be done - many people do just that on a daily basis. For the DIY enthusiast, it will be harder, because most are amateurs without electronics training. Experience is one of the best forms of education - you rarely forget things you learned the hard way.

There are countless debates on the Web and elsewhere about 'esoteric' components. Some may claim that silver wire (for example) will magically transform your listening experience ... it probably won't, but that's another issue entirely. Others claim that this capacitor or that resistor is so markedly superior that nothing else should ever be used. Again, maybe, maybe not. Only with the DIY approach can these claims be tested unless you have money to burn. Having equipment modified is expensive, and there's no actual guarantee that its technical specifications will be improved - indeed, in some cases the reverse is true. You are forced to believe that it sounds 'better' regardless of technical specs. Yet again, maybe, maybe not.

If you can make the modifications yourself, then the cost is minimal. You only pay for the components, and install them yourself. If there is no improvement (or worse, performance is degraded), then it is easy and cheap to revert to the original circuit.

As a DIY person, you will also be able to make (rather than try to buy) an AB switch box so that you can make direct (blind) comparisons, and find out for yourself if there is any difference between 'ordinary' and 'magic' components. More knowledge to you either way. Should you correctly identify the magic component 70% of the time, then you know it really does make a difference. Likewise if you hear no difference - you know this because you did the test! Without this first hand knowledge, you are the mercy of the snake-oil vendors and their often very convincing sales banter, or those who say that nothing makes a difference and all amps sound the same.

While I can tell you that neither side is right for the most part, it is only with your own curiosity and test processes that you will ever know the truth. Some things may make a difference in your particular case, but only experimentation will reveal what works and what does not.

Should you simply want to use the best components you can obtain, again, this is your choice. Most of the parts you buy will be no worse (and often much better) than those used in mass-produced commercial equipment anyway, you control the standard of workmanship, and if it fails, you will be able to repair it yourself. These are all major benefits, and to get the same benefits from any commercial product, it will cost you a great deal of money. If looked at from that perspective, then you actually will save by adopting the DIY approach.



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Contra-Indications

There are some important factors that you will miss out on if you follow the DIY approach, but in fairness to the hobby, they are only important to some people. Should you be the type who is impressed by the front panel, brand names, image, and fancy advertising, then DIY is not for you. You will get none of these things, and the appearance of the finished article will rarely be as fancy as the commercial offering.

Never mind that fact that many commercial products use a plastic front panel that may be dressed up to look like solid metal, or the likelihood that the internals are built on phenolic PCB (the cheapest available material). The chassis will be of thin pressed steel or maybe plastic as well as the front panel, and the top cover will almost invariably be thin sheet steel, with a spray coating.

But ... they are dressed up to look great, as long as you never remove the cover. The obviously cheap components in most consumer goods are probably not much worse than the ones you can buy, but the standard of workmanship often leaves a great deal to be desired.

None of this matters if you are only interested in the image. None of it matters if you update your gear regularly whether it still works or not. It definitely doesn't matter if you get the equipment for the right price and it does everything you ever want or need.

Of course, with time, patience and a willingness to pay for specialised work, you can build something that is vastly more impressive than the commercial offering - but if it lacks the image you are looking for, then your friends will fail to be impressed. This is regardless of performance, which in many cases is secondary to image.

So, if any of the above applies to you and/or your circle of friends, then don't bother. No-one but you will appreciate the effort you put into it, and without the image it might as well be salvaged from the local dump, or <insert>.

The image from DIY is the one that you create, and when all is taken in context, you have something of which you can be rightfully proud. If others don't like it, that's their problem, not yours. If it happens to outperform the system they paid $thousands for, then they probably won't be impressed, but usually not for any of the reasons they may claim.



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Conclusion

People choose DIY for the fun of creation, to learn, or to get something that can't be bought because it is too specialised - even in a seemingly minor respect. Sometimes, all three will be involved at the conscious level, but all three will be usually be involved at the subconscious level.

When you make something (even from a kit), you have the opportunity to customise it so that it does exactly what you want, not what someone else's marketing department told you you want. You will always learn from the experience of building it, even when it seems like a mindless chore stuffing components into a PCB and soldering them in. When it's finished, installed in your system, and doing exactly what you want, then the fun and pride of having made it will always be there - even long after the event.

Do you get any of these things when you buy a product? In a word, no. It is simply a commodity, something that countless others have, exactly the same as yours. If it doesn't do exactly what you want, then you have to live with it - even make excuses to yourself in extreme cases (where you'd like to strangle the salesthing given the chance).

DIY is not for everyone. Some people are forced into it because they can't get exactly what they want, and others do it because they think they'll save money. These are not good motives for DIY, although once they get into it, the motives will hopefully change.

The number one reason for DIY is simple - fun. Audio is a hobby for most people, and hobbies are meant to be fun - recreation at its best. In the same way that listening to your system is a recreational activity, so too is building your system yourself. As with all hobbies, there are new skills to learn, a complete jargon to master (that part is admittedly not so much fun), and something to show for it when it is completed.

Having acquired various tools (and talents) along the way, you may find that you can use them for other DIY activities - especially woodworking tools. Again, don't expect to save money. Many goods are available that are made in China (or perhaps India or some other developing country) for far less than you could build them for. Some are real bargains - well made, and will last well in normal use. Others are terrible - cheap materials, flimsy and with a marginal finish that won't last until next Thursday.

The old saying that 'you get what you pay for' no longer holds relevance - some bargains are real, others are very obviously false. Some highly priced goods are no different from the bargains, many having been made in the same factory (some may even be identical to a bargain version).

Again, the DIY approach is more about satisfaction and creation than anything else. If you do happen to save money in the process, then so much the better.

Finally, to get an idea of the reasons people get into DIY for the home itself (and yes, it is relevant), have a look at the UK site Social Issues Research Centre. There are differences of course - a house and a hi-fi system tend to be rather different by their very nature, but the reasons for DIY in any form are often very similar.

Mai vậy
Đâu mất biến mấy cái hình rồi
mini3


cmoy

Bass enhanced natural crossfeed Headamp

December 17, 2008 : Thiết kế xong mạch in
Mạch nguyên lí đây :



headAmp.pdf

Còn đây là mạch in



Có nhiều linh kiện quá không nhỉ ?

Chiều làm cái mạch in. Tối lại post lên

Mai mới có tiền mua linh kiện, tốn thiệt. Hàn vào nghe thử :-)

Còn nữa ...

December 18, 2008 : Thiết kế xong mạch in

Xong mạch rồi đây !

Mai sẽ làm cái hộp cho nó vậy, nhìn cho nó gọn.
Đang nghe thử ...





đây nữa ...



Và đây ...



December 20, 2008 : Hộp nè, hoàn thành thôi
Nhìn mặt trước bóng ghê :-D



đây nữa ...