First, what is a power amplifier?!
"Power amplifiers are devices that amplify and output signals from preamplifiers and mixers to drive speakers."
Power amplifiers play an important role in a variety of places including home audio and car audio, but this time we will look at power amplifiers being handled at Sound House that are for PA systems used at live events and concert venues.
The power amplifier is an important part of the heart of the sound, receiving signals from microphones, guitars, keyboards, and so on that are connected to an analog mixer with an equalizer, and then amplifying the mixed audio signal to an optimal balanced volume level that can be output through passive speakers.
There are various types of power amplifiers.
The standard type comes with a simple 2-channel output and there are only a power switch and volume knobs for each channel located on the front panel.
A multi-channel type of power amplifier is equipped with 4 channels (or more) in one unit.
More recently, the trend is multi-function power amplifiers with built-in DSP that adamantly state, "Amplification is not just about amplifying sound; we can also handle signal processing."
I often have end users asking me, "What models do you recommend?" But the answer is
"What do YOU want to emphasize?"
This time, I would like to introduce power amplifiers that I recommend which can be chosen from by "cost performance", "weight" and "sound quality".
Focus on cost performance
There is still a lot of need for good power amplifier within a limited budget.
We recommend the CLASSIC PRO CPX series for such people.
First of all, you’ll be surprised by the shockingly low prices. However, CLASSIC PRO’s price is not the only selling point. I am also confident of the sound quality!! Earlier, many staff members were amazed at the sound quality in a blindfold test which compared CLASSIC PRO with another power amplifier that was more than double the price. I was one of them. The excellent balance from low to high, the tightness of the lows, and the pressure when the volume is raised can be said to be "exceed the price range". A 4-channel model has been added to the already rich lineup of different output wattages, and giving you a choise from a total of 8 models.
Light weight
That's right. With older analog power amplifiers, the bigger the output, the bigger the transformer, making them 20-30kg; the more of these that you mount in a wooden rack case, and then try to move the rack case, the more your back will scream. But don't worry. Nowadays, there are power amplifier known as digital power amplifiers that achieve ultra-light weight by using small, lightweight and highly efficient switching circuits for amplification without using a large transformer. If you are looking for a light power amplifier, we recommend the CROWN XLS DriveCore2 series.
All of the models weigh in at 5kg or less!! Amazing! Light to a level that can be carried with one hand. This series is recommended for a number of points:
■ 3 types of input terminals
XLR, phone, and RCA making them compatible for just about any application.
■ Two types of output terminals
In addition to the locking speed controller, there is also a binding post so you can directly tighten banana plugs and loose wires for connections. No need for connectors!
■ Three types of filters are available
There are variable frequency low-pass, high-pass, and band-pass filters, so there is no need to provide an external channel divider separately when creating a two-way system that separates high and low frequencies and outputs to two speakers.
Sound quality is important
Another frequently asked question is, "Does the sound change with a power amp?" And the answer I always give is "honestly, a good power amp sounds good". Even if you are not dissatisfied with the sound of the power amplifier that you usually use, you will notice a difference right away if you hear the same output from a high-end power amplifier. The way I would explain it is that the highs are clearer, the sound is louder, but still has a naturalness that doesn't hurt your ears, and the lows sound more powerful, tighter and thicker. By increasing the amount of sound detail and reproducing detailed expressions, the overall sound is more vivid and the feeling of listening to a live sound increases. We recommend the QSC PLD series for those who want to focus on sound quality.
The PLD series is their flagship series, and combines pioneer QSC’s know-how of amplifier design cultivated over the years, with the power amplifier latest technology. Here is why I recommend this series!
■ High performance and lightweight
Adopting a combination of a custom power stage with new output devices, QSC 3rd generation class D power amplifier design, and a power factor collection (PFC) and power light power supply achieving high power, lightweight, energy-saving power amplifiers.
→ 400W × 4 channel, yet the PLD4.2 weighs only 8.4kg!! If you consider it as two high-end stereo power amplifiers, I think you’ll understand the excellent cost performance at only ¥ 118,000 (excluding tax)!
■ Flexible routing, compatible with various systems
Flexible Amplifier Summing TechnologyTM (FAST) enables flexibility of distribution of the total output as well as free routing.
→ Multi-channel capabilities allow you to choose from 1ch, 2ch, 3ch, and 4ch modes. In addition, you can set this output channel for each of the input channel signals, allowing for a variety of settings.
■ Speaker preset Wizard
Setup can be completed quickly and easily using built-in presets and user presets compatible with standard speakers.
→ Settings take into consideration the characteristics of each speaker enabling maximized performance.
■ High-performance DSP that brings out the full potential of speakers
Each channel is equipped with a crossover, 5-band PEQ, limiter, and delay to support any system.
→ No need for an external processors anymore. The necessary signal processing between the mixer and the power amplifier can be completed within the PLD power amplifier itself.
■ Front panel offers excellent operability
Equipped with an LED meter, LED indicator, 400 x 240 TFT color display, rotary encoder and navigation buttons, intuitive system control is possible.
→ The PLD series is a first-class product in terms of ease of use and visibility.
■ Dedicated QSC Amplifier Navigator software
Various settings that can be controlled on the large LCD display can also be controlled on a large computer monitor by connecting to a computer via USB which has QSC Amplifier Navigator software installed.
→ You can monitor the power amplifier level in real time, create detailed settings for each processor, and save and recall presets smoothly. It is more difficult to use than a simple power amplifier, but you can easily overcome the differences, but I think the PLD series advantages tip the scale in its favor.
So, what did you think?
There are various types of power amplifiers, each with their own advantages. If you choose according to importance of functions for your purposes, you will get to the desired model quickly.