PA Power Amplifiers: high volume, robustness and reliability are the things that count

Guitars, bass, drums, vocals – everything must be mixed and amplified before it is transmitted to the speaker systems and then subsequently to the ears of your audience. No matter whether you are standing in your rehearsal room and play music for your own ears only or are standing on stage and fire up the audience: you can barely be heard if you have not got amplification with an adequate output power. The most important part of your equipment is also the last one before the sound comes out: the PA power amplifier.Without: softest fingerpicking of a guitar and a voice which reminds you of singing ‘the wheels on the bus’ in kindergarten. With: giants on a stage which blow away the crowd in front of the stage by combining impressive riffs with a real rock voice.

• You provide the input, our PA power amplifiers provide the output

• Analogue PA power amplifiers: top performers which do as they are told

• Digital PA power amplifiers: maximum power, perfectly meeting any requirement

• All is well that ends well: with the right power amplifier, you cannot be ignored

• ​​​​​​​Active? Passive? What is what? – Things you should consider

• Have you heard that before? Our ‘vocabulary test’ on PA power amplifiers

Music ought to be heard. If you want to create a unique sound, you should be uncompromisingly creative and just focus your energy on that. You should have technology at hand which is reliable and perfectly suitable without having to invest much on setup and adjustments. With our PA power amplifiers, you can do anything you always wanted to do in your rehearsal room and on stage: deliver a performance to your audience, rock it or bring the dancefloor to a boiling point as a DJ or DJane. A user-friendly design and an impressive range of features both facilitate to deliver your music wherever it belongs: into your ears and into the hearts of your fans. You want to be heard? Then turn it up to full volume.

You are often faced with a difficult decision when purchasing a power amplifier: should the power amplifier be integrated or separate? Another question which arises is similar to choosing a mixer: analogue or ‘digital’? This depends on the requirements made on your equipment. Do you operate mainly in clubs and on smaller stages? In this case, it might be sufficient to use active speaker systems which are each equipped with an integrated amplifier. However, if you want to deliver a stadium atmosphere and you are playing on a medium-sized or large stage, you will require separate power amplifiers which use passive speaker systems and got much more oomph (to put it bluntly). You are able to connect them in parallel if required or configure them in bridged mode: this flexibility allows you to easily adapt to the respective size of the event.

With our analogue PA power amplifiers, you are surely getting a real all-rounder into your rehearsal room or on stage which is equipped with comprehensive features and ensures a reliable operation. The robust design ensures that they are perfect partners for your gigs, quite tough and meet any requirement. The analogue appearance is particularly well-suited for the purists among yourselves. There is a function behind every button and every control. The operation is very easy, even during hectic performances.

Our product range consists of analogue power amplifiers which provide you with a well-balanced sound. You can combine them for parallel operation or sometimes also use them in bridged mode for PA applications at really large events.

Our stereo PA power amplifier STA-500, 600 W

• Fan cooling

• 2 level controls

• Ground lift switch

• Speaker switch-on delay

Despite the comprehensive range of features, class D technology ensures that our digitalpoweramplifiers are lightweight and of compact size. An intuitive design and a clearly arranged menu ensure that you can quickly reach your goals: perfect amplification of your sound which knocks your audience’s socks off. Our digital power amplifiers provide a more energy-efficient and low-noise operation than analogue power amplifiers. With some practice, they are just as easy to operate.
 

No matter whether in your rehearsal room, with a small setup or on a large stage, our product range includes digital power amplifiers which perfectly support you at any music application.

Our class D PA amplifier STA-300D, 350 W

• 2 operating modes can be selected (stereo or bridged)

• Limiter function can be activated as required

• 2 level controls

• Temperature-controlled fan

Our class D PA amplifier STA-2000D, 2,400 W

• 2 stereo input channels (L/R)

• 2400 watt

• Silent operation due to temperature-controlled fans,

• NEUTRIK POWERCON and SPEAKON connections

• LEDs for indicating power, signal, bridge, overload (clip), overheating and protect

• suitable for fixed installations and mobile applications

You know what PA systems are for: to deliver a consistent sound radiation and above all a loud sound experience. However, what do PA systems consist of? Beside speakers and a high-performance analogue mixer or a digital mixer, the essential part of your PA system which you may bring to your gig yourself is the (full) amplifier (or power amplifier). Amplifiers are absolutely crucial. Otherwise, signals of the connected instruments or microphones may be delivered half-heartedly and you can only just be heard. And if your audience should be able to do one thing: they should hear you.

Just like the name suggests, amplifiers or power amplifiers amplify and process signals and forward them to connected speakers. Speakers are available in 2 different versions: active speaker systems which require their own power supply because they use integrated amplifiers, or passive speaker systems which must be connected to a separate PA amplifier, otherwise they stay silent. As a result, the electrical signals are turned into sound which the audience in front of the stage is able to hear.

When it comes to life, all that matters is performance, right? No matter whether school or job, even in a creative environment such as professional music, all that matters is performance. In this case, it is the performance your equipment is capable of.

At IMG STAGELINE, we consider our power amplifiers to be as follows: a perfect power amplifier combines a great performance with a low weight, small dimensions and low power consumption. The higher the efficiency, the less heat generation and other unwanted side effects will be present.

We will explain shortly what you should consider with your setup.

Amplifier classes

Full amplifiers are available in different classes and beside being determined by power capability, they are also differentiated by thermal capabilities and energy consumption, the efficiency class. The amplifiers use different methods for signal amplification and are divided into classes A to D. Most commonly, there are class ABamplifiers and class D amplifiers.

• Class AB amplifiers provide a clear and efficient sound due to low-distortion signal amplification with low energy loss by means of low heat generation. This is due to DC voltage which has to be applied permanently, even in standby mode.
• Class D amplifiers feature compact dimensions and a high efficiency. They operate with transistors using 2 switching actions only (stopband and saturation range). Thus, they show a frequency graph of the audio signal according to pulse-width modulation. Afterwards, a frequency graph is then released again via filters for driving the sound converters.

The power capability of PA power amplifiers

How much wattage you really need, i.e. power capability, depends on the PA application you want to implement. Small clubs feature a different environment than large open-air stages. Just remember, that you should rather think big: it is better to have too much wattage than not enough. If you constantly operate a smaller power amplifier at its limit, it will give up one day. Worst case scenario: your speakers blow up in your face. There is no problem the other way round: you can simply turn down the volume level with sound systems of a high power capability and not use them at full load. This is always possible and protects the material much more in the long run.

Thus, compare the stated RMS values (Root Mean Square) and also match speaker systems and amplifiers with regard to impedance (stated in Ω, ohms). In general, the power amplifier should feature a power capability of approximately 1.5 times higher than the speaker systems in order to avoid overload, also called ‘clipping’. For this purpose, it is also possible to use a power amplifier with integrated limiter. This is built into many of our analogue or digital power amplifiers.

Power supply of PA power amplifiers

There are 2 different kinds of power supplies for power amplifiers: standard power supplies and switch-mode power supplies. Standard power supplies are robust and available at a favourable price which is a great advantage. However, high heat loss and proportions are negative aspects: standard power supplies are actually heavy and of large dimensions. This is quite alright for basic PA systems with only 1 or 2 power amplifiers.

However, if you are on the road from gig to gig and are working with multiple PA power amplifiers built into racks, this can quickly be a huge disadvantage. High-quality devices from the higher price range often work with switch-mode power supplies. They are small, lightweight and do not heat up as much during operation.

Cooling of PA power amplifiers

Every electrical device generates heat, particularly power amplifiers because they require a lot of energy for amplifying signals. Thus, efficiency is reduced as well as electronical semiconductors (transistors and circuits) being  at risk. Therefore, PA power amplifiers are either actively cooled by means of a fan or passively cooled via air circulation. The active version is more efficient in a professional application if you have many performances where you assemble and disassemble the devices.

Protective functions of PA power amplifiers

High electrical currents are continuously flowing through electronic components. To protect yourself as a user against health hazards and your equipment from faults caused by overload, we have integrated various protective mechanisms into our power amplifiers:

• Protection against overheating: with a high operating temperature, the device is switched off automatically.
• Protection against DC voltage overload: DC voltage at the speaker which would destroy the equipment cannot occur.
• Protection against short circuit: broken cables or faulty speakers can result in a short circuit. Limiting the max. power protects the PA power amplifier. Thus, output transistors stay in a safe operating range.

What kind of requirements have you made on your equipment? Do you need a small but functional solution mainly for your recording sessions in the studio or are you touring the stages across the nation? Are you connecting your PA power amplifier to different speaker systems? Then, you must know a little about wattage, RMS, resistance, impedance, etc.
We have prepared a little something and want to test you:

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