Frickelfest (I love it)
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.