Classifications of Amplifiers
October 28, 2007
A device using small amount of energy to control large amount of energy is known as electronic amplifier and it is often used for audio applications. A transfer function of an amplifier is a relationship of input to the output of an amplifier expressed as input frequency. Its magnitude is termed as gain.
There are different classes of amplifiers. For example, A Class D audio amplifier is fundamentally a switching amplifier or PWM amplifier.
Various classes of amplifiers
"A" class amplifier always has bias current flowing in the output device. It is linear and has the least distortion in topology, but has the least efficient at about 20%. It is not a complementary with high or low side output devices.
"B" class amplifiers are totally different from A class amplifiers and for this the output device conducts for half the sinusoidal cycle. It is 50% more efficient than A class, but has some issue with linearity at the crossover point due to time it takes to turn one device on and the other off.
”AB” class amplifiers are a combination of the A and B classes which is at present one of the common types of power amplifiers in subsistence. Both devices are allowed to conduct at the same time with a little amount of modification near the crossover point. The device conducts more than half a cycle which the inherent non-linearity of B class overcomes with the inefficiencies of an A class. It has 50% efficiency.
"D" class amplifiers is a PWM amplifier which has switches either fully on or off, it significantly reduces the power losses in the output devices with the possible efficiencies of 90 to 95%. To modulate a PWM carrier signal, it uses audio signal to drive the output devices.
All these classified amplifiers are termed as linear amplifiers, in linear amplifiers signals always remain in the analogue domain. The output transistors act as linear regulators to modulate the output voltage. The efficiency is reduced when a voltage drops across the output devices. D class amplifiers have many forms, some with digital inputs and some with analogue inputs. So try to have amplifiers with analogue inputs.
Amplifiers A Boosting Equipment
October 25, 2007
Amplifier means a unit which can increase and amplify the sound volume. Here are some tricky tips to guide you when you are going to purchase car amplifiers. If your car is installed with speakers and sub-woofers and you want to boost up the audio system then follow these few tips to purchase car amplifiers.
Most of the time we see people who already have installed Hi-fi system with speakers, tweeter, sub-woofers in their cars. But this will trouble you due to its scarcity of wattages problem. It is wise to get amplifier to boost up the audio output.
Amplifier’s power is usually measured in RMS power. You must first understand the difference between the Peak and RMS power before buying car amplifier. The amount of power the amplifier produces for a short period is term as ‘Peak Power’, whereas the RMS power has the ability to reflect the sustainability of amplifiers power. RMS power is the only measurement which can display amplifier’s power accurately. RMS stands for root-mean-square.
Differences you can find in amplifiers: If you have only one speaker, it accepts mono amplifiers.
Two Channel Amplifiers supports you if your system has two speakers with sub-woofer. If you have audio system with three or more speakers and two or more sub-woofers then you can buy four channel amplifiers.
We often find people placing the amplifiers under the seat or car’s trunk. We know that amplifier is device which can soon get hot. Due to this reason, be aware to place your car amplifier in a space providing sufficient ventilation. Try to place your car amplifier at least two feet away, so it does not get interference with the radio’s receiver.
While purchasing car amplifier make sure that your selected amplifier has the correct installation kit. Purchasing a unique amplifier with complete car audio kit must work flawlessly.
Amplifier is not only used in cars but you can fit them to home entertaining Hi-fi systems. There are possibilities to get less audio in your Hi-fi system. But if you can make connection to amplifiers with your Hi-fi system, you can enjoy the thrill of theatre at home. Amplifier unit boosts up the Hi-fi system’s sound with its digital sound facility.
Amplifier with its Types
October 22, 2007
Amplifier is nothing but a device that uses little quantity of power to control a large quantity of power. It is referred to an electronic amplifier, often used in audio applications. The transfer function of the amplifier is the input to the output of an amplifier and the magnitude of the transfer function is termed as gain. We can find three types of amplifier devices and each has its strength and weaknesses.
A perfect amplifier will perform its task within certain set limits which will not add or subtract anything from the original signal.
Currently available amplifier devices are Vacuum Tube (Valve), Bipolar Junction Transistor (BJT) and Field Effect Transistor (FET). Derivatives of these amplifiers are IGBT Insulated Gate Bipolar Transistor and MOSFET Metal Oxide Semiconductor Field Effect Transistor which is a popular choice among many designers as it has desirable characteristics. It is most often used over any other transistor which is efficient and runs cooler.
An amplifier is supported by passive components that are resistors, capacitors and inductors, without these an amplifier can’t be build. These devices have various current outputs. It allows you to create a voltage amplifier. Valves and FETs are voltage controlled devices and Bipolar Transistors are current controlled. This means no current is drawn from the signal source. You can convert the current output of these amplifying devices into a voltage only using support components.
Now that you know the types of amplifiers you may love to know the purpose and its installation. The signal that comes from a radio, tape, CD player or some other source is very low at first in the milli-volt range. Then these devices are installed with pre amplifier which increases the signal voltage from the milli-volts range up to 1-4 volts or so. In some system these signals are from 5 Hz to 40 KHz, and most other has 20 Hz to 20 KHz. This signal is connected to RCA cables to the inputs of the amplifier.
So here is one good way to improve the audio effects of your music system. Use an amplifier and enjoy music to its fullness.
Yamaha RX-V359 Amplifier
October 8, 2007
Yamaha a reputed company has brought out their latest model of amplifier integrated with a range of technically advanced features to give you music with excellent clarity. Yamaha RX-V359 5.1 Channel Amplifier is a high standard device and it is a smart and modern amplifier which has come with infra-red remote control. The product comes with easy soft one touch buttons. The user will find it very friendly to use with its operating functions. The exterior part of the product is coated with sleek silver colour.
• Channels
The product is a receiver type amplifier system. The number of channels it supports is 5.1. The output power of the amplifier product requires 100 watts unit of the electricity per channel. The impedance at output power supported by the device is 6 ohms
• Sound Feature
The sound supportive feature of the Yamaha RX-V359 AV Amplifier is provided with surround sound of Dolby Digital such as Dolby Pro Logic, Dolby Pro Logic II, and DTS. The tuner integrated in the device is an analogue tuner. The wavebands provided in the product are AM (amplitude modulation) and FM (frequency modulation).
• Connections
The input connections of the amplifier are 2 optical digital connectors and a coaxial digital connector. The video input of the product is provided with 4 inputs for visual sources for DVD, Video etc. The audio inputs of the amplifier are provided with 6 inputs for Hi-Fi source for CD, Tuner etc. The product is provided with separate connection for sub-woofer.
Sony TA-FE370 Amplifier
October 5, 2007
Sony is the one popular company that has introduced a range of the electronic products towards the market. Sony has of late brought a new product into the UK market and it is the new Sony TA-FE370 Digital Amplifier. All the products from this manufacturer are of very good quality and its performance are really mind blowing. This product is also available at an affordable cost. This product is an amplifier that’s well tuned to give good sound.
The channel in this product is a stereo type channel. This will render you the better results in sound lucidity. This has got the ability to provide sound in surround quality and as well as in the Dolby digital quality. The power output that this product can give you is about 2 x 40 watts. This will be enough to compensate the need of special effects in sound tracks.
This is equipped with a remote control unit. This unit will help you to access the product even from a distance. This is also featured with tone and balance control functions. This tone control will stimulate the tracks to give you a good effect. Balance is something generally used that this can adjust the balance of the speakers sets according to the sound and the tone you select.
With all these in built equipped things, Sony TA-FE370 Stereo Amplifier weights only about 9 Kgs. This will be the best choice for those who wish to use buy a new amplifier.
