A Complete Guide to Different Classes of Amplifiers

In our previous post, we discussed 4 important things to look for when buying an amplifier. In today’s post, we’ll continue the discussion on amplifiers by explaining their different classes.

The electrical characteristics of an amplifier can be distinguished by class, thus known as amplifier classes. It defines the type of amplification used in the amplifier output stage. Adding to this, the output stage comprises of two sub power stages, one to amplify positive signals while the other to amplify negative signals. In simpler terms, the classes describe the topology of an amplifier, i.e., how they function at the core level. It is generally denoted by a letter or two.

Here’s a quick guide to different classes of amplifiers used commonly in home audio devices.

Class A

Class A Amplifiers are the simplest and most commonly used devices compared to other amplifier classes. These amplifiers are considered as the best class because of their low signal distortion levels. They deliver the best sound quality and keeps both the stages (positive and negative) on at all times. They have the highest linearity compared to other counterparts and generate the most heat as power is always present, thus delivering high-quality audio. Power efficiency rate of Class-A Amplifiers is 10-20 percent.

Class B

In Class B Amplifiers, current is pulled and pushed between the two sub-power stages, thus keeping one stage on and the other one off. Broadly speaking, if the input signal is negative, then the positive biased transistor switches off and negative biased transistor switches on whereas if the signal is positive, then the negative biased transistor switches off and positive biased transistor switches on. This arrangement creates a more efficient design, thus increasing its power efficiency rate which is 50% to 75%. However, the continuous on and off switching increases the distortion level.

Class AB

Class AB Amplifiers is a combination of Class A and Class B Amplifiers. It is a hybrid with the best features of both the classes, i.e., both the stages are always on for low-level signals and the stages alternate for high-level signals. Apart from combining the best features of Class A and B, this class eliminates their drawbacks as well by increasing the power efficiency and decreasing the distortion level. Currently, Class AB is among the most common types of audio power amplifier design.

Class D

Class D Amplifiers are at the top of the power efficiency rate, i.e., 90%. They are non-linear switching amplifiers that convert the input signals into a progression of higher voltage output pulses. These pulses go through a low-passive filter to remove unwanted frequency components and then transferred to the speaker. Irrespective of the high-efficiency rate, these amplifiers are not good in terms of sound quality.

The next time you plan to buy an amplifier, go through its class mentioned on the specification sheet. Each class of amplifier has a different electrical characteristic and is used for different purposes. Consult an electronic professional to gather more information on the classification of amplifiers before buying one.

4 Things to Look for When Buying an Amplifier

An amplifier is an electronic device used to boost the power, voltage or current of a signal from a musical instrument, a stereo system or any other audio-playing device. It picks up a weak signal and converts it into a strong one, thus making the sound louder without decreasing the quality.

Amplifier PyleAn amplifier should have certain specifications to really improve the sound. In the absence of those features, an amplifier fails to amplify the sound perfectly. Therefore, if you’re planning to buy an amplifier, look for these 4 things in the device before investing your money.

1) Power Rating

power rating of an amplifier refers to how loud your device can amplify sound. Many buyers believe in buying amplifiers with highest power capability but high power doesn’t mean good sound quality.

When buying an amplifier, look for the power rating according to space in which you want to amplify the sound. If you want an amplifier suitable for average listening in a small room, then 10 W power will be sufficient. However, if you want an amplifier for a music concert, then go for higher numbers.

2) Distortion Level

The distortion level is the amount by which the output of an amplifier is altered or distorted. It is denoted as THD, i.e., Total Harmonic Distortion and expressed in percentage. It is a crucial specification as high distortion level can make the sound unlistenable.

A lower distortion level is better as a lower percentage of THD means the output of the amplifier will be closer to the original recording. Therefore, always choose an amplifier with distortion level below 1%. A slight difference in the distortion level, say between 0.04% THD and 0.1% THD will not make a difference.

3) Signal to Noise Ratio (SNR)

A signal to noise ratio is a measurement that compares the level of amplifier’s signal power to the level of noise power. It is important because there is always a small amount of noise from the electrons buzzing inside an amplifier. If this background noise becomes prominent, then the music becomes inaudible. Therefore, consider buying an amplifier whose signal to noise ratio is higher so that you hear more of the music and less of the background noise. The larger the ratio, the better will be the separation between the sound signal (music) and the noise level.

4) Crosstalk

Crosstalk is a phenomenon by which a signal transmitted by one channel or circuit affects the other channel or circuit. In amplifiers, it refers to the undesired coupling between the channels of amplifiers. Measured in decibel (Db), crosstalk is when someone is talking on the right microphone but a little sound is coming out of the right speaker. Therefore, when buying amplifier look for the one with less crosstalk as higher crosstalk affects the stereo separation. For example, if A amplifier’s crosstalk is -100dB and B amplifier’s crosstalk is -60dB, then choose amplifier A because the larger the number following the minus sign, the greater is the stereo separation.

Look for these important specifications before purchasing an amplifier. The power rating, crosstalk, SNR and distortion level are all essential aspects that affect the quality of sound increased by your amplifier. Keep these points in mind to get maximum benefit from your purchase.

Everything You Need to Know About HDMI Splitters

In today’s digital world, HDMI splitters are the key to a comfortable life. From satellite boxes to televisions, HDMI splitters are used to distribute digital signage content from one input to multiple outputs. It is responsible for transmitting flawless digital audio and video signals without signal loss. Be it any media setup, these splitters are necessary to ensure perfect picture and sound quality.

Let’s find out more.hdmi-splitters

Meaning and Function

An HDMI splitter is a device used to split a High Definition Multimedia Interface (HDMI) signal into multiple signals to be displayed on various screens. For example, an HDMI splitter takes audio and video content from a DVD player, cable box or satellite box and displays identical content on multiple computer screens or televisions. This device works best for home offices, conference rooms, business centres and classrooms. Many people confuse it with an HDMI switch which is used to connect multiple HDMI source devices to a single television or computer screen.

Types and Specifications

HDMI splitters are available in several varieties such as 1X2, 1X4, and matrix combinations such as 2X2, 2X8 and 4X4. The most common type of splitter used is 1X2, used to split signals from one source to two display devices. For example, if you have two televisions in your home in two different rooms, then a 1X2 splitter can do the work for your by splitting the signal into two screens.

Most of the splitters used nowadays support HDMI version 1.4A specifications. They can support resolutions of 480p, 720p, 1080i and 1080p. If you’re using high-quality HDMI cables, then splitters can be used up to 50 feet from the splitter location to the television. In the absence of high-quality HDMI cables a maximum distance of 25 feet is recommended for transmitting signals without loss.

Benefits

  • It saves a lot of space as it has a sleek design and you don’t have to install a separate cable or satellite box for second screen or TV.
  • No signal is lost while splitting and high-quality audio and video signals are received.
  • It is easy to install as you don’t need an additional software program or gear. You can simply connect it to the source device using an HDMI cable.
  • It is compatible with most source and display devices.
  • It is available in matrix combinations to support a large volume of outputs.

Limitations

  • It drops the split resolution if the display devices have different resolutions.
  • It doesn’t work well with signal converters such as HDMI to VGA.
  • It doesn’t support Audio Return Channel (ARC) and HDMI over Ethernet (HEC).

HDMI splitters are the perfect device to view high-quality audio-visual images on multiple screens with no signal loss. It not only offers excellent picture and sound quality but also saves a lot of space. It has some drawbacks, but the positives are so good that this amazing device can’t be ignored. If you want to buy the latest HDMI splitters, then click here.

A Quick Guide to Installing Antenna Rotors

Antenna rotors are motor-driven devices that allow the users to conveniently rotate their outdoor TV antenna. A fixed roof outdoor antenna with a narrow beam width often fails to accommodate arriving signals from widely spaced directions. A rotor or rotator helps to get the desired TV signals by orienting the antenna in the direction of the specific channel’s transmitting tower.

An antenna rotor can help in eliminating different types of signal interference and/or adjacent channels through re-orientation of the antenna. It’s also useful to fine tune or increase the clarity of the TV signals that falter due to atmospheric or other conditions.

The control unit of a typical antenna rotor is placed near the indoor TV set. It comes with a digital display and a direction-calibrated knob. It’s manually operated with the control unit or by a remote to rotate the outdoor antenna automatically in the desired direction.

How to Install an Antenna Rotor

Installing antenna rotors aren’t difficult and average homeowners can do it themselves. Here are the steps to install antenna rotors made easy.

  1. Remove the fixed antenna from its current position and attach it to a short section of theAntenna mast. Keep the base mast fastened as it is.
  2. Measure the length of the existing mast of the antenna. The motor of the rotator will be placed on the top of the base mast. So, the existing antenna mast shouldn’t be longer than necessary to rotate. If the antenna is large with boom braces, a 3 ½ feet mast is enough; if the antenna is small, a shorter mast is ideal. In such a case, cut the antenna mast in length and reattach it with the mast.
  3. Attach the transmission line to the antenna terminals after removing the old transmission wires.
  4. Remove the access plate at the bottom of the rotor’s drive unit housing to attach the rotor wire. The most practical rotor wire has three conductors. All Channel Master Antenna rotors come with three conductor rotor wires. To attach, first strip 2 inches of the insulation on all conductors with the help of a wire stripper pliers and twist the wire strands together. Make sure there are no loose strands otherwise it might result in a short circuit or degraded performance.
  5. The rotor wire is colour The primary wire is red in colour and is connected to Terminal 1. The wire next to the primary wire is black in colour and is connected to Terminal 2. The third wire is connected to Terminal 3. In some conductors, the rotor wire is not colour coded. Here, the primary wire might be wider and you need to connect it to the three terminals in order.
  6. After you’ve connected the wires, cover each of the three connections with an insulating material to prevent rusting and corrosion. Then, fasten the bottom access plate of the drive unit or rotor housing.
  7. Now, attach the rotor housing over the base mast with ‘C’ clamps. Keep rotating the unit housing until the access plate faces your position and then fasten it.
  8. Place the short mast in position with which you had attached the antenna (as mentioned in Step 1) above the rotor unit housing. Make sure that the antenna terminals reside on the opposite side of the rotor housing terminals. Rotate as necessary before fixing it with clamps.
  9. On the base mast, about 4-6 inches below the rotor housing, attach a two-wire standoff. Attach the antenna wire and the rotor wire on each of the two portals of the standoff.
  10. Additional standoffs should be installed at 10 feet intervals. The number of standoffs used depends on the distance between the antenna and the entry point into the house.
  11. Drill an access hole to enter the antenna wire and the rotor wire into the house. You can also feed the wires through a window.
  12. Connect the antenna wire to the TV terminals that exist at the back of the TV.
  13. Connect the rotor wire to the control unit in the same way you had connected wires at the rotor housing, as stated in Step 5.
  14. Lastly, synchronize the control unit with the rotor drive unit housing. For a fully automatic system, plug in the control unit and turn the knob clockwise and let the antenna rotate until it stops. As the antenna rotates, the control unit clicks. When it stops rotating, turn the knob anti-clockwise and let it rotate until it stops. Thus, the synchronization is successful and the installation is complete.

Remember, there could be variations in installation procedures depending on the model of antenna rotors. Always make sure to check the instructions given on your product manual sheet before installation.

The Different Types of RJ45 Connectors

Modular or Network connectors are electronic connectors that were initially designed for telephone wiring but they rapidly evolved technologically. Finding its use in many applications, these connectors are now also used for data networks and low-speed serial connections. Also called RJ connectors, they have a tab for locking the jack and plug in place when connected.

Developed by AT&T in the 1970s as part of a coding system (Universal Service Order Code or USOC) to classify telephone equipment and services, RJ stands for “Registered Jack”.  It’s basically a standard that’s used to specify the capabilities of different types of jacks.

What is an RJ45 Connector?

An RJ45 connector is the most common type of twisted-pair network connector that generally has an 8-position, 8-contact modular plug and jack (8P8C). It’s used to connect computers with Ethernet-based LAN or Local Area Networks and can be commonly found on Ethernet cables. T568A and T568B are two wiring schemes that are used to connect the cable to the connector interface.

Types of RJ45 Connectors

There are several types of RJ45 connectors available. While the older FCC RJ45 connector has become obsolete in the current telecommunications industry, the other types are very popular.
RJ45

  • Category 5 

Commonly abbreviated as Cat 5, it was originally made for a rated line speed of 100 Mbps, transmitting at 100 MHz frequencies. It has a maximum cable distance of 100 metres and generally uses two twisted pairs. At a later phase, Category 5E was developed for providing a line speed of 350 Mbps. It introduced new cables to accommodate four twisted pairs.

With a good signal and over short distances, Cat 5 and Cat 5E can transmit Gigabit Ethernet speeds.

  • Category 6 

This type of RJ45 connectors has stricter standards and significantly more enhanced shielding. It’s designed to provide a native speed of 1000 Mbps over a 250 MHz frequency. It supports 10-Gigabit Ethernet mode by reducing the maximum cable range from 100 metres to 55 metres.

Category 6A is a more advanced technology as it increases the transmission rate to 500 MHz from 250 MHz.  With a grounded foil shielding, it also effectively reduces noise interference.

  • Category 7 

It’s designed to support 10-Gigabit Ethernet speeds at a transmission frequency of 600 MHz. It has the same enhanced shielding introduced by Cat 6 along with the added advantage of individual shielding for each of the four twisted pairs. Cat 7 modular connectors have a maximum cable distance of 100 metres and are also compatible with Cat 5 and Cat 6.

There is also an advanced variation of this type of connector which is known as Category 7A. It can support future 40/100 Gigabit Ethernet speeds by increasing the transmission rate at 1000 MHz frequency. It also allows transmission of lower-frequency cable TV streams.

Buy high-quality modular connectors from RTC Electronics at the best prices. We’re a leading wholesaler and retailer of electronics in Canada since 1996. You can also shop for the latest electronics brands online at amazing deals from our e-commerce website. We have a comprehensive shipping program to ensure fast and reliable delivery to our customers.

Subscribe to our newsletter !

scroll top