[MASantos]

What is a capacitator ? and a buffer? a buffered output??

all the amp sites and manufactures speak about these and their advantages, but I just don't know what they are! Is there any site where one can read about all the components of an amplifier?

I found it very confusing to understand the caracteristics, functions and differences of the components!!

help needed!

MASantos

 

[Chisum]

Uhhhh.... this is going to be very hard to explain in short terms, especially with my very limited knowledge of the English language ... Anyway, I'll try:

1.) The power supply is very important for any amp. This is simply because there are electronical parts inside the amp, which operate with DC power, so the AC voltage from your local power station has to be transformed and converted to DC. Extremely important is a good filtering stage so that you do not get any influences from the "outside", e.g. other electrical stuff in your household, that could disturb your signal. Capacitators are parts that can "store" electrical energy, and that are able to "release" this energy to supply the load, i.e. your headphones, with the power that is needed to drive them.

2.) The input stage allows you to attenuate the signal that is reaching the "real" input of the amplifier part. That means, you need a potentiometer or a stepped attenuator to control the signal level that is going to be amplified. Or simplified, it is the volume control part of the amp.

3.) The voltage amplifier is doing what it is supposed to do: amplifying the input signal, so that you can get proper volume levels with your headphones. There are a lot of different approaches to do this, and each has it's own characteristics and followers: disrete transistor stages, operational amplifiers (OP-AMPS), tubes.... it all depends on the designer, and the customer

. The different amplification methods often are associated with a certain sound character, e.g. tubes=warmer sound, solid state=cleaner sound...

4.) The output stage is also very important, because the phones which are connected to the amp also need a certain amount of "juice" (current) flowing through them to move the diaphragms, i.e. to produce the sound that the fellow listener wants to hear. The amount of current depends on the "complex resistance" (impedance) of your headphone, the lower the impedance, the more current is "sucked" from the amp, and the better the output buffers have to be.

OK, hope that helps.... it is indeed a VERY simplified look on this kind of stuff, but I hope I got it right (at least a little bit)....

Cheers

Chisum

 

[drewd]

Quote:

Originally Posted by MASantos What is a capacitator ? and a buffer? a buffered output??

You can think of a capacitor like a battery - it is a component that stores energy. Capacitors serve two purposes in an amplifier. The first is that they provide a ready reserve of energy for the transistors or integrated circuits when they require a lot of energy quickly. Those capacitors are typically electrolytic - they're usually the ones that look like little cylinders or cans. Other capacitors are used to block dc voltages from entering the signal path. That's important because you don't want a small dc offset at the input to be amplified into a large dc offset at the output. Those capacitors are usually film (polyester, polypropylene or teflon) and look like little boxes.

A buffer is a circuit, either integrated or discrete transistors, that converts the voltage output of the amplifier into current that most headphones and speakers respond to. They're particularly important for low impedance headphones that require a lot of current to achieve whatever voltage is necessary for the desired volume. They're also helpful in isolating the gain stage of the amplifier from the varying levels of impedance of different headphones. So, buffered outputs are outputs that are connected to buffers - the gain stage (an opamp or some transistors) drive a buffer which, in turn, drives the headphones.


Quote:

all the amp sites and manufactures speak about these and their advantages, but I just don't know what they are! Is there any site where one can read about all the components of an amplifier?

Like all things, there are advantages and disadvantages. You might start by looking at Tangent's web site (http://www.tangentsoft.net/audio) and review some of the articles that he's written. Once you've done that, you can take a look at the Pimeta and PPA amplifier pages and read about their theories of operation. That may give you some more information about how everything works together.

Quote:

I found it very confusing to understand the caracteristics, functions and differences of the components!!

Welcome to the club! It just takes time and research! Have fun!

-Drew