Apparently there is some sort of football tournament on, but to be honest, it’s so far passed us by here at XTA, such has been the feverish activity with the launch of the APA Series at InfoComm this week. From the feedback we have received so far, it feels like all our efforts are being rewarded with great positive interest from you, not just in person at the show, but all over the wwworld.
I needn’t turn this post into a sales pitch for the new amplifiers – you can read all about them elsewhere on the website, but I will take this opportunity to dispel a couple of myths regarding the background of the amplifier and its design – things that are being speculated upon on a variety of forums and social media, only 24 hours after the launch!
As many of you may well know – we started research into Class D amplifier design way back in 2003, where we undertook a joint project with our good friends at Funktion One. They wanted amplifier modules for their subs and famous Resolution series of speakers. As we already supplied them with their OEM processing (in the form of the X01, and currently with the XO2 and XO4A) and they were willing to collaborate with us on the this first foray into digital amplifiers, we were both destined to hopefully learn a lot and end up with some great products at the end of the project.
And that’s exactly what happened – over the course of the next three or so years, we designed and built two immensely powerful digital amplifiers with a full suite of XTA DSP inside (at 96k – still a big thing way back then!), along with full remote control capabilities, in addition to ground-breaking protection systems that have since been introduced in many other manufacturers’ designs such as error logging, and supply monitoring and low power standby modes. The A4 and A6 modules delivered 2.5kW and 5kW peak power respectively, in a footprint the size of a phone book (A6 – the big one). Cramming this much power into such a small area and making sure it is robust enough to be tumbled about in the back of a sub cabinet taught us a lot about the right (and wrong) things to do. Clever tweaks to the software as the designs developed added hidden features such as adjustment of limiter time constants in reaction to over-modulation of the output stages to keep the amp up and running as long as possible, and even adjusting fan speeds not only due to temperature conditions, but with peak signal levels to help pre-empt thermal build-up – all these things would prove useful to have discovered when we came to starting with a clean sheet and the design of the APA.
The merger with MC2 Audio after this added even more amplifier know-how into our growing R&D pool of resources. They had the background of lightweight switching amplifiers in the form of the hugely successful E Series, but one of our first collaborative projects was the introduction of some intelligence into the more workhorse T Series, to make them more appealing as installation amplifiers. Thus the Ti Series were born, incorporating traditional great sounding Class AB amplifier technology with more installation friendly features such as remote control and monitoring, speaker load alarms, mains power-up sequencing, simple level and standby remote adjustment for incorporation into existing building management systems.
Going hand in hand with the introduction of the Ti Series amplifiers, were the first forays into audio networking technology – the Ti Breakout boxes. These boxes could pick off 8 or 16 channels of networked audio (Dante or CobraNet) and feed a rack of Ti amplifiers – the whole shebang being remotely connected back to a PC for control, configuration and monitoring (via iCore – the software that was also developed). They also had another card up their sleeve, which was their ability to learn about all the other connected amps and breakouts on the network (even over Ethernet hops). This enabled one breakout box to be switched to a “Master” mode whereupon, without intervention of a PC or any remote device, it would monitor and report back on all amps and breakouts, giving feedback if any amps’ loads went out of spec, got too hot, or disappeared off the network.
As can be seen from all this research and a steady progression of product development, the APA Series have been born from a vast amount of hands on acquired first-hand knowledge.
Let’s make one thing clear too – the power supply, the power stages, and even the DSP platform used in the APA Series are not culled from any existing MC2 or XTA products. This is not a cut and paste design – sure we have learnt lots along the way and there will be elements of the amplifiers that have built on what we already know, but that’s the “D” in “R&D”!
For example – the DSP platform shares some algorithms with our flagship processor, the DP548, but (remembering that the DP548 is a 4 input and 8 output processor) doubles the power available (and we are only processing 4 channels in the amplifiers). The power supply is power factor corrected and designed to operate with no need for range switching – truly universal worldwide use. The output power sections are over-engineered with devices capable of current delivery far in excess of what is asked of them, to provide ultimate reliability and low stress (both to them and you!).
It’s an XTA design through and through – even extending to the careful consideration of the display and user interface. Whilst the unit is fitted with a full colour LCD screen – you could be fooled into thinking it’s just a monochrome display. This is very deliberate so as to use colour effectively – you’ll only see red on the screen when there’s something you need to know about urgently (an alarm condition). This way, a glance at the amps doesn’t require you to study the screen – if there’s no red anywhere, all is well! Similarly with the metering – all looks pretty normal and you might never know the LED bars weren’t anything other than standard green yellow and red. However – start driving the amps above the limiter thresholds and the meters will swap to red and start reading “downwards” to show gain reduction. Again – a quick glance is all that’s required to confirm everything as it should be.
Now the launch is underway, we might be able to take an evening off and catch up on some of the football – at this point England are apparently still in the running…however, let’s just say we don’t think we will be glued to the TV for long 😉
