Ground Zero’s GZUA 6SQ offers an appealing level of sound quality for a product in its price range: smoothness at medium and low volumes, and vanishingly low distortion when the dial is cranked high. The six-channel amp stage includes two fed by a separate power supply and offering increased output, making it a fine choice for three-way systems, while upgrades to temperature management and heat dissipation allow it to comfortably handle low impedance loads and channel bridging. Bias adjustment lets the user fine tune the step between Class A and Class A/B operation, and therefore sound characteristics, to personal taste. This is a superb addition to Ground Zero’s Uranium series, improving on previous two-channel and four-channel designs.
