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How does gain work on an amplifier

In work and life, many of us strive for a constant or a routine. Moreover, if you are a perfectionist and a planner like myself, a routine is a must. Furthermore, discovering a routine for anyone is a path to a norm, and I dare say a more efficient day to day life. However, as it is in math and science, life is also filled with the events and circumstances that are the polar opposite of constant, the ever-present variable.


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WATCH RELATED VIDEO: Amplifier with gain control

What’s the Difference Between Gain and Volume?


Written by Grant Maloy Smith , the data acquisition expert. In this article, we will discuss signal amplifiers, specifically those that are used in the world of data acquisition DAQ systems. At the end of this article you will:. A signal amplifier is a circuit that uses electrical power to increase the amplitude of an incoming signal voltage or current signal, and output this higher amplitude version at its output terminals.

The ideal signal amplifier creates an exact replica of the original signal that is larger but identical in every other way. Signal amplifiers are an essential component of thousands of devices, including landline and cellular telephone systems, music and public address systems, data acquisition DAQ systems, radio frequency transmitters, servo motor controllers, and countless more.

There are several types of signal amplifiers, each capable of conditioning different signal types. Here is a list of some common signal amplifiers found in today's data acquisition systems:. The purpose of a guitar amplifier is to take the low-level output from an electric guitar and make it sound good. It has nothing to do with accuracy which is irrelevant in this application , and everything to do with aesthetics.

Typical electric guitar amplifier Image by Free-Photos from Pixabay. However, the purpose of a DAQ system is to make accurate, objective measurements of signals. Therefore, all aspects of the system are designed to preserve signal accuracy. Again, the ideal signal amplifier should not distort the original signal in any way. So how can we achieve this? Here are the elements that are most often specified:.

Input ranges are the selectable input gains that can be applied to the signal. It has to perform equally well regardless of whether it is amplifying the signal, attenuating it, or neither unity gain.

What if the wrong range is selected? The result will be less resolution when digitized and a poor signal-to-noise ratio. Selecting too large of an input range causes a loss of resolution. There will be relatively few pixels containing a cat in the resulting image. Move closer until the cat fills the frame, and the entire resolution of the camera is used to capture the cat. On the other hand, if you stand too close you can only take a picture of part of the cat, right?

Parts of the cat will not be in the frame at all. Left: ideal input range Center: input range too large Right: input range too small. Engineers have struggled for years with this quandary. They want to select a range that will provide them with the best possible resolution, but some signals are unpredictable and will increase in amplitude during a measurement far beyond what was expected.

This would work, but it is very inefficient: using two channels for every input signal would require twice as many DAQ systems in order to do the same work. In addition, it would make data analysis after each test much more complex and time-consuming. These two ADCs always measure the high and low gain of the input signal. This results in the full possible measuring range of the sensor and prevents the signal from being clipped.

This is 20 times better than typical bit systems with 20 times less noise. The rated bandwidth of this model is 70 kHz. In fact, this is a delta-sigma ADC with bit resolution and built-in anti-aliasing filtering. One of the characteristics of delta-sigma ADCs is that they sample much faster than the selected rate.

They use powerful DSP electronics onboard to derive an output data stream with very high amplitude axis resolution, in this case, bits. This scheme also prevents aliased i. To achieve the best possible bandwidth and anti-aliasing results, a combination of technologies is used:. So how was this achieved? It is well-known that every filter imposes a phase shift, so how is this possible? This leads us to filter in the digital domain as opposed to the analog, however, digital filtering cannot be used to prevent aliasing.

Therefore, by first filtering in the analog domain to block aliasing, and then filtering in the digital domain, this is possible. But for the best phase results, we should use an FIR Finite Infinite Response filter , one of the most demanding computations among filtering, requiring a lot of processing power. In addition, its delta-sigma architecture includes over-sampling, which raises the Nyquist frequency and improves signal quality. The result is the very steep roll-off at a predictable frequency, in this case, 70 kHz.

In all cases, it is important to match the instrument with the application. For nearly every DAQ measurement within the physical electrical and mechanical domain, the bandwidth offered by the SIRIUS series of signal amplifiers is more than adequate. When specifying a DAQ system most people look at the sample rate as the top speed of a car.

Racecar Image by Peter Fischer from Pixabay. It is clearly related to the bandwidth that we discussed above. In a bit system, a sample is two bytes, but in a bit system, it is four bytes. So while the sample rate is not specifically related to the analog part of the signal amplifier itself, in the case of SIRIUS with its built-in ADC system, it is a valid concern because of the tight integration of the analog and digital elements of the signal chain.

As shown earlier, these sections have been designed as a single system in order to achieve the best possible performance. Gain accuracy is the accuracy at which a signal amplifier can amplify a signal. For example, if we have a 1.

The difference between the ideal amplification and the actual amplification is the gain error. The ideal signal amplifier would have no gain error at all, but in reality, there is some error in every system. Gain error is a magnitude measurement expressed normally as a percentage of the actual signal reading.

But it can also be given as a percentage of full-scale, which can be very different. Hypothetical system A specifies gain error at reading, while hypothetical system B specifies it at full scale.

To test it we insert exactly the same 10V signal into both systems. When the signal is at 10V and our range is 10V, the gain error should be identical in Systems A and B. This means that no matter what the signal amplitude is within a given range, the gain accuracy error will not change.

Gain drift is therefore normally expressed as the number of parts per million per degree change in temperature. Note that although their zero or reference points are drastically different, Kelvin and Celcius have the same magnitude. So one Celsius degree is the same magnitude as one Kelvin unit. Its gain drift is specified as:. So in this case, two specifications are provided: the typical drift expected under everyday operating conditions, and the worst-case maximum drift which might be experienced under extreme conditions.

Of course, we need to know where we are starting with the temperature, so manufacturers normally provide the baseline operating temperature or range of operating temperatures of the instrument in question. Linearity refers to how well an amplifier can output amplified signals that are accurate copies of the signals that we put into it. No amplifier is perfect, of course, but a linear amplifier is designed specifically to handle this challenge.

We want our amplifier to make as perfect a copy of the original signal as possible, but simply at a different amplitude. Unlike gain accuracy, which relates more to the magnitude of the signal being amplified, offset accuracy is related to the accurate Y-axis positioning of the baseline of the signal.

Due to the very wide range of this amplifier, the specifications are a little different depending on the range. As with the gain drift specification that we discussed earlier, offset drift is the tendency for this parameter to change over time based on changes in the ambient operating temperature. Again, two specifications are actually provided here: the typical drift in a normal operating environment, and the maximum drift when the system is being used in an extreme operating environment.

Dynamic range is perhaps easiest explained using music. One of the advantages of the music CD when it was introduced compared with vinyl records and cassette tapes, was its dynamic range. Basically, this is simply the difference between the softest and loudest sounds that the medium could express. Dynamic range is the ratio between the largest magnitude undistorted signal and the smallest magnitude signal. To measure this in a way that can be repeated across systems, a signal like a pure sine wave at 1 kHz and a fixed magnitude like 1.

So how does Dewesoft achieve such a high dynamic range? Ordinary DAQ systems have dynamic range specifications below dB. The first explanation is the use of bit delta-sigma ADC technology. The music CD mentioned above is a standard from the s that allows only bit music to be stored on the CD. If you consider that every single bit that we add to the resolution doubles the number of values that can be expressed, it is clear that bit ADCs provide vastly more quantization than bit ADCs.

But that is just the beginning because even other DAQ systems with similar bit ADCs do not achieve these specifications. As the name implies, this is the ratio between useful signal content, and the background or unwanted signal content noise that has crept into the signal chain.

This specification is closely related to the dynamic range described above. Dewesoft DualCoreADC technology dramatically improves the signal-to-noise ratio of SIRIUS measuring systems by use of two independent bit ADCs set to two different gain apertures and then combining their streams into a single stream with the lowest possible noise floor and best possible dynamic range and signal to noise ratio.

This is easy to imagine in a sound amplifier because the noise can literally be heard behind quiet passages of music. But it is present in all systems, especially those which amplify electronic signals to a higher level. Because we cannot accurately measure any signal whose average amplitude is lower than the noise floor, this parameter is important to know about and understand. This is an isolated 8-channel thermocouple signal conditioner. The noise floor is specified at two sample rates, and at two gains:.

DAQ system users are apt to say that a high impedance input is better than a low impedance input. But why? Basically, the higher the impedance of input is, the less current it will draw from the connected signal source.


Variable Gain Amplifiers (VGA)

Similarly, guitarists and bassists use gain all the time, yet many would be hard-pressed to tell you clearly and correctly what gain is, exactly, and how it relates to volume. Granted, you needn't be able to define "gain" in order to use it-you just know you turn that knob and something cool happens to your sound; usually something to do with distortion. That's perfectly OK, but if you're new to amps - more specifically, new to buying an amp - it might help to know what gain is and how it's related to volume, as the two are closely related. Some amp basics are in order first.

Each configuration is illustrated with a block diagram, gain equations, and an example using realistic scenarios to illustrate to engineers how to calculate.

What Is A Gain Control? (It’s NOT a Volume Control)


We all live in a world surrounded by the wonders of amplifiers. Or the speakers pouring music through your radio on a lazy Sunday afternoon, amplifiers again. In this world of amplification, the goal is simple — to boost the electric current and voltages up a notch. But are all amplifiers created the same, or used for the same purposes? Definitely not. Ever get your hands on a hearing aid? Hearing aids use a microphone to pick up sounds from the external environment, which then gets turned into an electrical signal. Amplifiers are what make hearing aids possible. I mage source.

Your Amplifier’s Gain Control Is Not A Volume Control

how does gain work on an amplifier

This article explains how to set amplifier gain to achieve optimal loudspeaker levels in a sound system. In many cases, available amplifier power exceeds the power required to produce the desired sound pressure level SPL at the listener location. Even if the system is capable of producing very loud levels without exceeding the ratings of its components, it is often preferred to limit the end user's available range as to not exceed reasonable sound levels for the application. This article assumes that the gain settings of devices earlier in the signal path have been verified for best performance, and that the voltage arriving at the amplifier does not exceed its maximum peak or RMS voltage ratings, as described in the Gain structure and Input and output levels articles.

The amp parameters include controls for the input gain, presence, and master output.

Gain vs Volume: The Practical Differences That Matter


The Mod. Channels are non-inverting and bipolar: they amplify both positive and negative signals. Gain setting can be performed independently for each channel via four rotary handles. Channels can be cascaded in order to obtain larger gain values. Each channel is provided with three LEMO 00 connectors, one for the input and two bridged for the output. Build: License Accept.

What is Gain & How It Differs from Volume

Their misguided theory is that this setting will limit the maximum amount of power the amplifier will produce. Imagine a world where every car radio provided the exact same preamp output voltage at full volume. In this scenario, every amplifier on the market could be configured to produce its maximum rated power when it sees 2 volts of input signal. In reality, the sources we use to play our music vary dramatically in their output capabilities. An iPod might produce millivolts.

For a single amplifier to work with multiple sources, amplifier manufacturers have to make the input signal level adjustable. We call this the gain or.

Saying ‘Gains Set Halfway’ Is Concerning to Car Audio Professionals

Last Updated: September 16, This article was co-authored by wikiHow Staff. Our trained team of editors and researchers validate articles for accuracy and comprehensiveness. This article has been viewed , times.

In electronics , gain is a measure of the ability of a two-port circuit often an amplifier to increase the power or amplitude of a signal from the input to the output port [1] [2] [3] [4] by adding energy converted from some power supply to the signal. It is usually defined as the mean ratio of the signal amplitude or power at the output port to the amplitude or power at the input port. The term gain alone is ambiguous, and can refer to the ratio of output to input voltage voltage gain , current current gain or electric power power gain. Furthermore, the term gain is also applied in systems such as sensors where the input and output have different units; in such cases the gain units must be specified, as in "5 microvolts per photon" for the responsivity of a photosensor. The "gain" of a bipolar transistor normally refers to forward current transfer ratio, either h FE "beta", the static ratio of I c divided by I b at some operating point , or sometimes h fe the small-signal current gain, the slope of the graph of I c against I b at a point. The gain of an electronic device or circuit generally varies with the frequency of the applied signal.

Having an understanding of the differences is crucial and can alter the way your mixes sound for the better! Continue reading to find out how you can craft better mixes with a proper understanding of volume and gain.

Explaining how they are different is easy, but the real question is whether or not there's a practical difference. Let me break it down simply for you At some point, no matter if you're learning to record music, be a mixing engineer, toying with your first guitar pedals, you'll be asking the question "What's the difference between gain and volume? To the untrained mind, they seem like they're the same. They both make audio louder when you increase them.

Sound Design Stack Exchange is a question and answer site for sound engineers, producers, editors, and enthusiasts. It only takes a minute to sign up. Connect and share knowledge within a single location that is structured and easy to search. Have read a few descriptions and understand basically what gain is, but I am quite the novice with audio work.




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