Let me just start off by saying, "NOW THIS IS AN AMPLIFIER!" I often get these boring aluminum "box" amps across my desk that have nothing inside them that pushes the technological boundary-in fact, it seems as if technology means flashy heatsinks that contain some form of neon, acrylic or chrome to so many car audio manufacturers. Well, the JBL A6000GTi is not just another aluminum box. And it's not just neon blue glow tubes under the acrylic cover either. Hell, this amp is so serious it takes at least two people to move it! Arriving in a wooden crate weighing 145-lbs, we knew that this amp had to be something spectacular. Fortunately, we had been forewarned that this amp consumes mega amounts of juice, so we started working to prepare our test bench before it arrived. Once we got it unpacked though, we weren't sure if the power we had on tap was enough to truly put this amp through its paces - the electric bill's going to be high this month!
Features·Power! Four tons worth! ·Very high efficiency·Low distortion·High quality components throughout·Severely overbuilt·Adjustable crossover damping·Parallel, bridged, & dual output operation Magnetic interconnect safety switch
CosmeticsWith the car audio business already saturated with box-shaped aluminum amplifiers, the team from JBL and Crown decided they needed to make an impact. These guys dumped some serious coin into the design and development of the multi-piece chassis and the tooling of the little things such as the terminal blocks on the A6000GTi. Its sweeping die-cast aluminum curves, clear window, neon, and matching covers for the input and output connections all make for a very stylish and modern design that have this amp holding its own in the originality category.
Design And LayoutThe construction of the BIG JBL is truly unbelievable, both internal and external. The power supply section is unique in that it has a massive transformer surrounded by switching devices arranged in a circle. This keeps the path lengths short and consistent, improving the performance of the supply while making it visually stunning. JBL took extra measures to prevent any radiated noise from contaminating nearby components or audio paths with some exceptional shielding. And to assure that the power remains clean are a cool quarter farad of low ESR capacitors on the supply. The A6000GTi uses an unregulated power supply. While regulated supplies in Class AB amplifiers improve efficiency, they offer no such improvement in switching amplifiers such as Class D, or in the case of our subject, Class I. Class I (Interleave) or BCA (Balanced Current Amplifier) was developed by JBL's sister company, Crown International, as a proprietary design. Crown, as you may know, manufactures some of the most powerful audio amplifiers worldwide. Speaking of power, this amp is in a class of its own, using 48 170-ampere switching FETs in the supply, helping it achieve greater than 85-percent efficiency into a 4-ohm load. The advanced switching technology of the BCA design solves many problems that Class D amplifiers have, including switching losses and power supply pumping, while maintaining the ability to bridge the outputs.
Even the speaker and power connectors are top notch and can accommodate 1/0-gauge power wire and 4-gauge for the speakers, ensuring that maximum power is delivered to and from the amplifier.