I suspect that Executive Editor/Publisher John Gatski was undergoing ear recalibration after the birth of #1 son when he asked me to do the hands-on review of QSC’s SRA 1222 ($1,499). Usually I’m relegated to bench testing and technical write-ups, but I don’t mind an occasional hands-on review, especially of a QSC product.
Product PointsApplications: Studio
Key Features: Two-channel; Class AB; DataPort; short circuit, RF, ultrasonic, open circuit, thermal protection; compatible with QSC processing modules
Contact: QSC Audio at 714-754-6175, Web Site.
With a 200 watt per channel at 8 ohms rating, the SRA 1222 is the baby in QSC’s “Studio Reference Amplifier” two-channel series and is a tad different from the others. The 2422 and 3622 flesh out the SRA line with 8-ohm ratings of 425 and 725 watts/channel, respectively, employ QSC’s well-regarded high-frequency switching power supplies to reduce size and weight, but the 1222 is the only one with “conventional” Class AB output stages. The others feature two-tier “switched-rail” or “Class H” topologies to jack up efficiency.
Quite remarkably, all SRA amps fit in the same package, a 3.5-inch 2RU case that extends 15 inches behind the mounting rail and a half inch in front. If I’m to believe the specs, they even weigh the same, 10 kg or 22 pounds. Kinda says a lot for what switching power supplies can do to keep the size and weight down! The amps are cooled by an ultraquiet variable-speed fan that couldn’t be heard during my listening tests.
A brushed aluminum front panel carrying the QSC logo disguises the air exhaust ports and makes this one classy-looking piece of equipment. The power rocker is on a black recessed panel to the left of center; the power, signal and clip LEDs are on a similar panel to the right. This security cover plate can be removed to access the gain controls which are factory preset to max (a voltage gain of 28x or 29 dB). Needless to say, hiding the controls makes adjusting gain a pain in the you-know-what, but it does eliminate accidental resetting and I think it’s a good idea!
On the back apron are XLR balanced-input jacks, RCA pin jacks for unbalanced inputs, a 15-pin D-sub DataPort to interface with QSC’s optional crossover and DSP modules, a pair of Speakon jacks, and four binding post/banana-plug jacks on standard 3/4-inch centers so they can be used with “GR” plugs. The binding posts are heavy duty and handle 10-gauge wire; the two “positive” connectors are to the center to facilitate using a “GR” plug when the amp is bridged.
A 10-section DIP switch lies between the inputs and outputs. The three upper and lower-most sections activate the DIP limiter and infrasonic filter of each channel and offer a choice of cutoff frequency (20 Hz/50 Hz). The four center sliders determine the operating mode: stereo, bridged or parallel. Parallel operation is possible only from the XLR inputs. The XLRs then are internally connected so either can serve as the input and the other used to daisy-chain to another amplifier. On the other side of the air intake vents is a pair of parallel connected 3.5mm mini-phone jacks that can be used to remotely power-up the amplifier from either a contact closure or a 12-volt DC signal.
SRA series amplifiers feature short circuit, open circuit, thermal, ultrasonic and RF protection and are claimed to be stable into reactive or mismatched loads; I detected no sign of misbehavior during my listening tests. I used the SRA 1222 in three situations: to drive the front speakers of my home theater system (Paradigm 9se-MkIII towers) from a Sony DVP-S7700 via an EAD TheaterMaster Ovation controller and using an Adcom GFA600 amp to drive the center and surrounds; in my main listening room driving Mirage OM-8 speakers using a Bryston BP-20 Preamp and (still unrivaled in my opinion) Sony XA7ES CD Player as the main program source, and in my office with a pair of venerable Allison monitors.
In all cases, I used the balanced inputs with the clip limiters and filters off. The sound was never less than satisfying, and in two out of three situations — the home theater and office setups — blew away what I had been using. Only the slightly more powerful Bryston 4B-ST amp in my main listening room gave the QSC SRA 1222 a run for its money and that’s some mighty stiff competition! The SRA 1222 grabbed onto wayward woofers and delivered tight clean bass which I consider a primary attribute of a good power amp. Midrange was exemplary; treble tended toward the sharp and crystalline rather than smooth and silky. Depends upon what you’re looking for. I’d have no difficulty whatsoever living with a stack of these in my surround system. They not only look classy, they sound classy!