I dont know where to start.

Hey everyone, amplifiers has been my latest obcession and I am very happy I ran across this site.

I have gotten through the first 150 pages or so of electronics for dummies, and my goal is to be able to repair amplifiers and mabye create them. I have a pretty good knowledge of water and air cooling(I am building my own watercooling setup for my computer for about $50), turbos, auto performance and repair, and car audio. However when it comes to electronics I didn't know where to start.

Again, I want to repair car amps, and mabye build my own car ro home amps. When I got onto this site I have no diea where to start, I looked for a newbies section but didnt find much. I am interested in learning everything about amplifiers and abotu all kinds, I am basically a nerd(I am 16) who is into all kinds of things instead of just computers. I know electronics basics but have very little electronics experience. As soon as I get my debts from my system paid off (about 2 more weeks) I am going to go buy a bread board, resistors, capacitors, etc. and make my own small amplifier out of an LM386 amplifier.

Could someone explain or show me the difference between the types of amps? [Chip, Solid State, Tube (I know it uses a vaccum tube, that about it:p) etc.]
 

EC8010

diyAudio Moderator Emeritus
2003-01-18 7:57 am
Near London. UK
Welcome to the forum! Where to start? Well, paying close attention in maths and physics classes is a good start.

The different sorts of amplifiers are all down to the type of device that provides the amplification. All amplifying devices (usually known as active devices) control the flow of electrons. In vacuum tubes (or valves in Britspeak), the electrons flow in a vacuum. In solid state, yes, you guessed it, they flow in a solid lump of semiconducting material such as silicon or germanium, and the device is known as a transistor. If you make lots of transistors on one piece of silicon and connect them together to form a circuit, it's known as an integrated circuit, or chip.
 
lol like i said, I got throught he first 150 or so pages so I know what ICs , transistors, diodes, etc. are. I just have had a chance to work with them yet. I actually arent even in physicis yet and wont be fore like 2 years, I have problem learning on ym own. Math is sorta my forte, I am a sophmore with seniors in my class. (Algebra 2) Why do electrons flow well in a vaccum? Why are these good for SQ? Why arent they used in high SQ car audio applications? Is it because they cant flow enough, is thier electrical resistance high (although I dont see how it could be, theres nothing in the tube lol)

If you put a printed circut board in front of me, told me to point out all the compnents and put them where they go, I could do that. If you asked me to tell you why they work the way they do, or why they go where they do, I probably wouldnt be able to tell you everything. And if you asked me how the hell does it amplify sound? I would say idk ask DIYAudio.com.
 
tupacglock said:
Why arent they used in high SQ car audio applications?

They don't really like being jiggled around, they produce their share of heat and they are somewhat expensive to replace. Solid state is also smaller. Aside from that...

Welcome to the forum. Glad to see your interest is piqued. Hope you make a go of your ambitions.

Cal
 

EC8010

diyAudio Moderator Emeritus
2003-01-18 7:57 am
Near London. UK
Actually, valves are far more robust than people think (they survive roadies and musicians' vans). The reason you don't see them in car audio is that apart from some weird devices in the last thermionic fling, they require voltages about ten times higher than silicon and they squander power in their heaters. There are ways around this, but by and large it's usually easier to use silicon. Besides, a car is hardly a critical audio environment...
 
EC8010 said:
valves are far more robust than people think (they survive roadies and musicians' vans).

Not to mention older Russian jet fighters (i'd much rather be in one of those than any high tech american airplane in the event of an EMP event (atomic explosion))

There are ways around this, but by and large it's usually easier to use silicon. Besides, a car is hardly a critical audio environment...

Bob Danilek (of Darling fame) has tube amps in his car -- but it takes a switching power supply far more complicated then the amp to make it work. In the old days car radios used something called a vibrator (no idea how these work -- EC?) to get the voltage up.

dave
 

EC8010

diyAudio Moderator Emeritus
2003-01-18 7:57 am
Near London. UK
planet10 said:
In the old days car radios used something called a vibrator (no idea how these work -- EC?) to get the voltage up.

The vibrator was simply a steel spring switch plus nearby electromagnet. When the spring was away from the electromagnet, it applied power to the electromagnet, thus attracting it, but as it moved towards the electromagnet, power was broken. Thus, the switch sat there vibrating, alternately opening and closing its contact. Additional sets of contacts could alternately reverse or not reverse polarity of the car battery to a transformer so that the car battery was applied to the transformer as a square wave at the frequency of the vibrator, allowing it to be stepped up to whatever voltage was necessary. I expect some tricksy ones used the transformer primary as the coil for the vibrator. As you can imagine, these things were horrendously noisy and required careful filtering to stop them squirting RF hash all over the place...
 
Welcome to the forum! :)

I'm sure you'll find lots of info here, although I found that some basic knowledge is needed.

Car amps are one of the more tricky things to start with, due to their supply, so I'd start with a home amplifier, running from a "normal" power supply.

If you don't have any practical experience yet (hands on stuff), I would start with a small chip-amp (which is a small power amplifier with most stuff inside). Then you'll only need a power supply and a few extra components. This is probably your best chance for success.

When comportable with that, and you've learned WHY it works, and which part does what, I would move on to a kit. Rod Elliot in australia has a number of designs available, including PCB's. I think you will have to go shopping for the components yourself, but at least you have directions where to put which component.

Another thing you could do, is to download a copy of my DIY notes. They were originally a series of posts written to answer questions from a guy who was in a situation just like you. (see my tag line for details, and please do let me know if you find it useful, or what you would like to see in there).

What sort of electronic tools do you have (or have access to)?
A multimeter and soldering iron is a minimum, I would say. Later on, an oscilloscope would come in handy, but they're kinda' expensive.

Wishing you good luck...
Jennice
 
tupacglock said:
I thought Jennice was a guy and that were all guys here? Sorry though.


Erh... Yes, I'm a guy. (and as far as I know, I've been all my life). Just to make sure, my g/f just helped me check this morning... :D

I believe there are a few girls on the forum, but if in doubt, I would take the chance and assume that a forum member would be male.

I don't know what has originally been posted (and edited), but I don't care about the mistake really. I have my own problems, trying to figure out names (whether male / female) when it comes to the asian continent. (Being european, I have it a little easier with the american continent). The use of (more or less obvious) handles does not make guessing easier for anyone, though.


Jennice
 
Yea I am american but have a thing for europian girls. Paritcularly danes.

In america if you replaced the e with an A itd be Jannice which is a womans name (although usually spelled differently)

Either that was the mistake or they are extremly strict here about keeping the talk about audio and not the lady folk. Its a good thing this is in the noob section. :p
 
Jennice said:
Hmm... Maybe the moderator just wore his hat (or something else) a little too tight? :clown:

Anyway... My handle gets mistaken frequently. Maybe I should think of something better, or give people a clue somehow.

Anyway... back to the main issue here...
You might want to check out Rod Elliot's projects here:
http://sound.westhost.com/

thanks fo r that site i have to look after work but it looks like what i am looking for
 
If I recall correctly, many of his projects have PCB's (Printed Circuit Boards) available, but you will have to go shopping for components yourself.

Tou will notice that his projects page dos not reveal all secrets about his projects (such as component vales), but you'll get access to them by buying PCB's. Maybe you can buy his CD for details, also, but I'm not sure about it. Drop him a mail.
Maybe I should state that I don't have any personal interests in guiding people to his site, but he knows what he's doing, and a number of people (on this forum, too) have had success with his projects.

Jennice