The modern-day power amplifier is truly a work of art and science. It weighs less, delivers unheard amounts of power to ridiculously low impedances, has numerous protection stages and delivers years of problem-free service. QSC, a leading amp manufacturer, offers a two-channel amp that has a low-power channel, a high-power channel and an internal crossover system. This new model is the PowerLight 3.8X.
Product PointsApplications: High-end touring or theater installation
Key Features: High-power channel and low-power channel; internal filters; lightweight
Contact: QSC Audio at 800-854-4079
The QSC PowerLight 3.8X ($2,898) is a three rackspace power amplifier identical in appearance to its PowerLight predecessors. The difference is that the two amplifier channels have two different power ratings.
QSC offers the following specs: Channel 1 has 900 W at 8 ohms, 1,400 W at 4 ohms and 2,400 W at 2 ohms. Channel 2 has 450 W at 8 ohms, 800 W at 4 ohms and 1,400 W at 2 ohms. There is also an optional filter, the QSC UF-3, options available by using certain chips, signal processing card aligned in specific orders that provides high-pass and low-pass modes filtering.
The chip card also has the capability to add EQ for constant directivity horns, which allows for more even distribution of higher frequencies. Installing these filters requires a fair amount of dexterity and soldering skills – you may want to have the filters factory installed.
The QSC PowerLight 3.8X is a clean, well-thought-out package that only weighs 30 lb. It is shipped without the mounting handles attached, but those take only a few minutes to install. There are optional rear rackmount ears to solidify the installation in portable racks. The power cable is quite hefty, offering a 30 amp/125 V twist-and-lock-type connector.
The front panel is simple and to the point, each channel having a notched/incremented input sensitivity control that is friendly in both use and placement. The on/off switch is located on the front panel and the amplifier turns on in steps (soft-start) to avoid drawing large amounts of current on start-up and tripping breakers.
The back panel features a concentric input connector that is both 1/4″ and XLR on each channel. The output posts are located just next to the inputs. These are far more convenient than the standard hex-shaped nuts – the posts are slotted, permitting the use of a flat-blade screwdriver to tighten them. The back panel also contains a large air intake fan for sufficient cooling on even the hottest day. A feature on all PowerLight Series amps is an HD15 data port connector for computer control of the operating parameters of the amp.
I should tell you upfront that I have been using QSC PowerLight 4.0s and 1.4s for about a year in our proprietary JBL four-way system. When I was asked to review the PowerLight 3.8X I was already familiar with the performance of previous PowerLight units.
The unit I received came with factory-installed internal crossovers, a frequency of 1,200 Hz and a slope of 24 dB per octave. I wired up the rig, and headed off to my gig at Phoenix Symphony Hall, featuring the Phoenix Symphony Orchestra with Doc Severinsen conducting and playing.
I initially tested the 3.8X in the monitor system, wiring it to the biamped JBL 4704 15″ monitors. I attenuated the driver channel significantly because this amp provides more power in Channel 2 than I dare employ. That notwithstanding the monitors sparkled. The crispness of Severinsen’s trumpet and the piano, drums and bass of the rhythm section were unmatched.
I then proceeded to rig the PowerLight to the house speaker system, at first using it for subs and low mids. The power supply delivers instant current to the amps, allowing for full, responsive bass frequencies usually only found in heavy, conventionally power-supplied amps. The low mids had transparent, natural frequencies of 100 Hz to 1,500 Hz, giving the lower registers of the vocals uncommon warmth. After four days of testing at every frequency range, I found the 3.8X to be everything I have come to expect from QSC.
If you need power amps that are quiet, clean, great sounding, lightweight and extremely roadworthy, then the QSC PowerLight Series of amps are for you. This particular amp is well-suited for bi-amped monitors, offering some of the best sound I’ve heard in a critical monitor application. Be careful running drivers and tweeters, as you may want to back off on the Channel 2 volume – it’s a bit more than some will safely handle. I found QSC’s customer service department one of the best I have encountered. The folks there answered all my questions with succinctness and friendliness.