Comparison Cambridge AXA35 vs Cambridge Topaz AM10

Most modern amplifiers have toroidal transformers - with a toroid-shaped core, in other words, a donut. This type is considered optimal for amplifiers of any level up to Hi-End: it creates a minimum of "extra" electromagnetic radiation and, accordingly, interference. Some time ago, E-core transformers were also widely used, but they are considered obsolete and are becoming less common today.

This indicator describes the amount of non-linear distortion introduced by the amplifier into the processed signal. Such distortions are not necessarily perceived as extraneous noise, but they degrade the quality of the sound anyway — for example, they can make it more deaf. It is almost impossible to avoid them, but it can be reduced to levels inaudible to the human ear.

As a result, the harmonic distortion factor (harmonics) is one of the main parameters describing the overall sound quality in Hi-Fi and Hi-End amplifiers. The lower it is, the clearer the sound. Hundredths of a percent are considered a good indicator for modern amplifiers, thousandths and below are excellent. The exceptions are tube and hybrid models, for which rather high harmonic coefficients are allowed; see "Element base" for more details.

The type of connector used to connect headphones to an amplifier.

— 3.5 mm (mini-Jack). The most popular audio connector in modern portable electronics, also found among stationary equipment. However it is considered not as suitable for high-quality sound as 6.35 mm Jack, since it gives an increased likelihood of interference at the connection point. On the other hand, the vast majority of modern headphones, of all price categories, are made specifically for this connector. This means that the presence of a mini-Jack socket in most cases will allow you to connect headphones directly, without the use of adapters — that is, in the best way.

— 6.35 mm (Jack). This connector is typical mainly for stationary audio equipment, including professional class. It provides a better connection quality than the mini-Jack (in particular, less resistance due to the larger contact area), and is also more durable and reliable. At the same time, it is worth noting that only some high-end headphone models are equipped with a “native” plug under such a connector; and to connect the popular 3.5 mm mini-Jack you will need an adapter, which can affect the sound quality.

— Bass adjustment. The presence in the amplifier of a separate low-frequency level control, in other words, bass volume. The ratio of low and high frequencies largely determines the overall picture of the sound; the optimal options for this ratio for different cases will be different, and they depend on a number of factors — from the type of audio being played to the personal tastes of the listener. Anyway, the bass control provides an additional opportunity to fine-tune the sound of the entire system. It is often combined with a treble control (see below); in fact, this combination is the simplest version of the equalizer.

— Treble adjustment. The presence in the amplifier of a separate volume control for high frequencies. The meaning of this function is completely similar to the bass control described above, only it works with a different frequency band.

— Balance adjustment. The presence in the amplifier of adjusting the balance between the channels. This setting is used in stereo sound: by changing the position of the knob, you can increase the volume for one channel and decrease it for another. Due to this, the conditional centre of the perceived sound shifts towards the speaker that sounds louder. This feature can be very useful for correcting the sound stage — for example, if the speakers have different sensitivity, badly placed, or the signal itse...lf is not properly balanced. At the same time, the balance controller introduces additional elements into the design, which increases the likelihood of interference. And therefore, in top-class amplifiers, it may not be provided at all.

— Adjustment of input sensitivity. Ability to change the input sensitivity of the amplifier; For details on this parameter, see "Input Sensitivity (Line Input)". Also note here that the adjustment itself can be useful when working with several sound sources: it allows you to easily reconfigure the amplifier for each of these sources in order to provide the desired output power level and at the same time avoid distortion.

— Level adjustment. The presence in the amplifier of its own level control, in other words, a system that allows you to change the volume of the sound (by changing the actual output power). In modern home amplifiers (see above), this adjustment is common to all channels, and it is responsible for the actual volume; sometimes using the control on the amplifier is more convenient than on another component of the audio system. But in concert models, each channel, usually, is equipped with its own regulator, thanks to which there are many opportunities for fine-tuning the sound to a specific situation.

— Loudness. This function allows you to adjust the tone of the sound at a low volume. Its necessity is connected with the fact that the human ear perceives a quiet sound differently than a loud one; because of this, even high-quality sound at low volume will seem “blurry”, not clear enough. Loudness corrects this by boosting certain frequencies. Usually this mode is enabled by the user at will.

— Direct connection ( By-pass/Direct). The ability to turn on the amplifier in By-pass / Direct mode. Its name is due to the fact that the signal is sent directly to the amplification stages, bypassing all additional controls (timbre, balance, etc.). Power amplifiers (see "Type"), by definition, use just such a scheme of operation. In integrated models, direct connection not only minimizes distortion in the processed signal, but also provides the sound closest to the original, which allows demanding listeners to appreciate the skill of sound engineers.

— Automatic power off. This function ensures that the amplifier automatically turns off if no signal is received from its input for a certain period of time. In this way, downtime is avoided — for example, if the owner left on business, forgetting to turn off the audio system. And considering that many modern amplifiers require a lot of energy even “at idle”, the savings can be quite significant. It is worth clarifying that in this case we are usually not talking about a complete shutdown, but about switching to standby mode; but the power consumption (see below) in this mode is usually so small that in fact the difference is practically not noticeable.

— MM phono stage. The presence of a phono stage in the amplifier for working with turntables equipped with MM type pickups (with a moving magnet). The phono stage itself is a mandatory attr...ibute of models with a Phono input (see "Inputs"); its necessity is due to the fact that the signal from the pickups for vinyl has specific characteristics and needs additional processing. At the same time, two types of pickups can be used in modern record players — the already mentioned MM plus MC (with a moving coil), each with its own signal characteristics. Therefore, for the normal operation of the turntable, you will anyway need a phono stage of the appropriate type. Such equipment is also available as separate devices, but it is usually easier and cheaper to buy an amplifier with a built-in phono stage.

— MS phono stage. The presence of a phono stage in the amplifier to work with turntables equipped with MC type pickups (moving coil). For more information about this function, see the subsection “MM Phono Stage” above.

— Limiter. The presence of a limiter in the amplifier — a device that limits the dynamic range of the processed signal. This device is also called an "audio signal compressor" (due to the fact that it "compresses" the dynamic range). In simpler terms, a limiter essentially reduces the difference between the quietest and loudest sound output from an amplifier. This feature can be useful in any situation where you have to deal with uneven sound volume. For example, a limiter can make it more comfortable to listen to a symphony that has large volume differences — so that the listener can access the slightest nuances of sound and at the same time, loud fragments, as they say, do not beat on the ears. And for professional concert activity, the presence of a compressor is almost mandatory — in particular, to compensate for changes in volume that occur when the distance from the microphone to the acoustic instrument or the vocalist's mouth changes. Of course, the limiter can also be made as a separate device; however, its presence in the amplifier itself is sometimes more convenient. At the same time, this function is complex and expensive, and therefore is found mainly in professional equipment and top-class consumer models.

— Connecting an additional speaker. The ability to connect an additional set of speakers (one or more) to the amplifier. Note that we are not talking about individual speakers, but about sets designed to work with full-length sound. In other words, if such an amplifier produces sound in stereo format at the main outputs (see "Number of channels"), then an additional set of acoustics will be able to work in this format. Models with this function are designed primarily for situations where you need to output sound to several rooms, and the signal can go either to all sets at once, or only to one at the user's choice. Also, an additional set of connectors can be used for Bi-Wiring (see below).

— Biwiring. Amplifiers with this feature use two separate channels of amplification for bass and treble, and are able to output each frequency band through a separate set of connectors. Due to this, it is possible to apply low-frequency and high-frequency signals via separate wires, and directly to the corresponding specialized speakers of the speaker system — instead of outputting a common signal to it and dividing it into frequencies using the built-in speaker crossover. In fact, this means that the Bi-Wiring connection reduces the likelihood of interference and improves the sound quality. However, keep in mind that this will require not only an amplifier, but also speakers that support this function. Note that Bi-Wiring is usually combined with the ability to connect an additional speaker described above.

— Management of external devices. The ability to use the amplifier as a control device for other components of the audio system — for example, preamplifier, turntable, etc. Control is usually carried out from the universal remote control supplied with the amplifier, and the control signal is transmitted through special connectors — this is much more convenient than adjusting each component separately. On the other hand, the construction of such systems is possible only from devices of the same manufacturer — different companies use different control standards, in most cases they are not compatible with each other.

— Bluetooth. A wireless communication technology with a range of about 10 m (more "long-range" versions are not used in amplifiers), originally created for direct connection between various devices. The functionality of such a connection may be different, but in this case, most often it is possible to broadcast to the sound amplifier from an external device — for example, a smartphone or laptop. However, other functions may be provided, for example, remote control from a mobile gadget through a special application.

— Emergency notification. The ability of the amplifier to work in an emergency warning system, more precisely, the availability of special functions and tools for working in such systems. Such tools may include, for example, connecting to fire detectors and automatically triggering warnings or evacuation messages to areas where the detectors have been triggered; selection of message type depending on the triggered sensor; connecting the notification microphone to the “priority input” and muting all other channels when sound is received from the microphone, etc. A specific set of features should be specified separately. Specialized security units may also be responsible for these functions, but sometimes it is more convenient to use an amplifier with built-in support for emergency notification.

Possibility of operation of the amplifier with a remote control(the latter is supplied).

The advantages of this function are obvious: You do not have to approach the device every time in order to change the operating parameters. Moreover, some settings in modern models can only be accessed from the remote control. And separate amplifiers with this function have IR control outputs (see "Outputs") and can also work as sensors for transmitting commands to other devices. The remotes themselves can be made "learnable" — with the possibility of programming.

Power consumption of the amplifier in standby mode.

In this mode, most amplifier components are disabled; power is supplied only to the control circuits. Their only task is to accept a command from the user at the right time and put the device into operation. The consumption of these circuits is extremely low and is unlikely to have a significant impact on electricity bills; at the same time, the exit from the standby mode is faster than turning it on from scratch, and the command can be accepted from the remote control (which is impossible in the absence of power). Therefore, most "off" amplifiers are usually in the standby mode.