can somebody show me how to make a amp?

[wizkid]

i want to make a amp i just need to know how it works then i could modify
with some big ass components

[Fallen]

Goto www.diyaudio.com and learn something new.

[thechris]

yes, there are 3 main parts to Car audio amplifiers:

1.) Power supply to convert 12V to either +-6V or higher.
2.) signal processing. the high or low pass filter
3.) audio amplifier.

==Part 1==
part 1 is the more complicated issue. you can get +-6 V from the battery though. best results will be had using a better PSU. this will derive from a buck topolgy despite the "boost" of voltage.

you will have a transformer wound on a toroidal ferrite core. perfeably materal 77 or F or some other power material. you can use some design graphs to determine the optimal wire size and such.

next is the power mosfet. irfz44n or others will work. digikey has fets on sale under =irf . but its 50 for $25 or such.

the nxt part is the diodes for the secondary. choose a diode with a fast recovery time and sufficient current.

the last 2 parts are the important parts. there is the output inductor, whice will be some combination of molypermalloy, sendust, high-flux, #26 or #52 iron powered in a toroid form. the large DC currents make ungapped ferites useless for this app. but you can use ferrite rods as well.
the capacitors should be rated for low ESR if possible, and should be in parallel with other, smaller monolythic ceramic caps.

more later.

[Gebrochen]

You can't just swap out parts and massively build up an amp. The whole thing is designed to work together. The best you could do without knowing a lot about AC and DC circuits is upgrade the caps in the power supply or replace the MOSFETs with ones capable of handling higher current. Even if you do replace them, there may be other parts on the board that can't handle it. You'd be better off finding a schematic of a large power amp and building your own from scratch. However, you probably can't build your own any cheaper than you can buy one. With today's manufacturing, it's cheaper to just buy one already made.

http://search.yahoo.com/search?p=amp...&cop=&ei=UTF-8

If you're serious about doing this, I can point you in the right directions. I'd suggest starting off small, though. Buy some of these electronics kits where you solder the parts together. Go to Radio shack and buy one of the 120-in-1 electronics experiment kits, etc. That's how I got started.

[Gebrochen]

http://www.hobbytron.com/Amplifier.html
http://www.apogeekits.com/car_audio_amplifier.htm
http://www.electronickits.com/

[thechris]

ok, continuation. because of the PSU issues -- the DC-DC converter is not the best 1st task and the parts are hard to find -- i'd say you could start with a headphone amplifier or such.

an amplifier is basically comprised of 3 main stages. at least classic, linear amplifiers. (linear means a non-class D amp).

1.) differential input stage.
2.) voltage amplification stage
3.) current amplification stage.

==long tailed pair==
the differential input stage has at least 2 transistors. the emiiters (bjt) or sources (fet) are connected together. the idea is that the output of this stage is the difference of the input voltages, multiplied by a gain. there isn't a huge need to make this gain too high and its probably best to keep it reasonable.

==vas==
the VAS amplifies voltage. it is normally made of 2 transistors, 1 npn (nfet) and 1 pnp (pfet). if the ltp was based on N devices, the input to the VAS will be a P device. the collectors (drains) of the devices are in some way connected, but a resistor or "vbe multiplier" might be in series with the connection.

the N type device is a current source in most cases -- this means that it will try to draw a constant current from the P type device. if the ptype device provides less current, it will try to draw the excess current from the next stage. if the P type device provides more current, that current will go to the next stage.

==class A output stage==
this output stage works on a similar idea as the VAS stage (the VAS is also class A biased). in a classic class A output stage, there are 2 transistors. the lower device is again an N type device (as in the VAS) and draws a constant current (equal to the maximum current to the load).

the upper device is also an N type device. in this case the emitter (source) is tied to the CCS's collector (drain). this gives this stage a voltage gain of 1, but a high current gain (if needed).

==feedback==
at this point there is an amplifier that can amplify the difference of two input signals by a large voltage AND provide high currents if needed. but we'd rather have a fixed gain of say 10V/V, or 20V/V. so we will make one input to the amplifier be the input signal, and the other input will be some fraction of the output.

now the amp will try to keep the fraction of the output equal to the input signal, and gain will be fixed and all will be well.

==problems==
sadly transistors are often too good. lets say there is a delay of 100ns through the amplifer due to parasitics. for audio, we don't care about the 100ns delay, but we can't ignore it. if the amp has a high gain (above 1) at 10Mhz, any signal will cause the amp to correct itself, but the correction will take too long to make it through, and then will be correct for again, but larger. in short the amp will oscillate.