We’re stationed in the anechoic chamber again, looking at Axiom’s latest amplifiers, the ADA series. Axiom’s Engineer Andrew Welker takes us through a few of the inner workings of the ADA amplifier, and what sets them apart from the rest of the amps on the market today.
Andrew: Basically today I wanted to go over a couple of points about our ADA amplifier series that differentiates us with some of the Class D (sometimes called Switching Amplifiers) that are on the market. There’s a lot of them and they all tout the same sort of high efficiency, cool running, high-power-for-small-size features. We have all of those things, because this is a Class D-based amplifier.
In fact, this module in my hands is from the ADA 1500 amplifier, our largest model, and this is essentially a complete (minus the power supply) 2 times 650-watt into 4 ohm amplifier. It’s something that was unheard of not that many years ago – to get that sort of power out of something so small.
But as I said, there are a lot of companies doing Class D now. However, there are a couple of things we’re doing that we do a little bit differently from most of the products in the market. One is that we use a conventional – sometimes called ‘linear’ – power supply, with a large toroidal transformer and massive amounts of power supply filter capacitance. Basically we’ve gone that route because we find that a linear power supply works a lot better when you have to divide power amongst a number of different amplifier channels, as you find in multi-channel amplifiers. And we’ve also discovered that they’re quite a bit more reliable than a switching type power supply.
One other thing that separates our amplifiers from most of the amps on the market is that our series is completely modular and factory-upgradable. The bottom of the amplifier chassis is what we call a power supply motherboard that delivers all the power supply voltages to the different amplifier modules. The modules themselves can simply plug in to positions on the motherboard to allow us to configure the amplifier in anything from two up to eight channels.
This means that a customer who buys the amplifier in a two-channel or three-channel configuration can easily upgrade at any time by simply sending the amplifier back to the factory, as their power requirements and their system evolves over time.
Amie Asks: What is meant by Power Supply Filter Capacitance?
Andrew Answers: Power Supply Filter Capacitance helps in the conversion from Alternating Current from the wall to turn it into direct current to supply the amplifiers. Having a large bank of them functions somewhat like a battery – they store energy. So the larger the bank is, the larger the size of the capacitors, the more energy storage there is. So what that means is when you have short term peaks where you need a lot of power, the power supply is able to deliver it without dropping in level at all. So they’re a large energy storage bank.
Ian Adds: The large capacitance adds something known as dynamic headroom, and since large power in music and movies is normally demanded for very short bursts of time, allowing the amplifier to deliver these bursts of power without clipping.