Bass Gear – July 2011-Issue 6
The output power of this amp is where things really get terrifying. At four ohms, the amp was able to crank out 519 watts continuous, with a burst power of 972 watts (cue the theme music from Psycho). The amp handled dynamics and transients well under lab conditions. It does appear as if the non-defeatable limiter can really clamp down on the Signal, and the limiter appears to have been programmed with a relatively long release time, exhibiting a recovery that exceeded one second in our dynamic burst signal. Results from our burst signal test are illustrated in Fig. I.
The amp also performed well in our gain tests. As the input signal was swept over a range typical of bass signals, the output and distortion products behaved predictably and linearly up to the steady state limits of the amp, as illustrated in our plot of distortion as a function of output in Fig. J.
The preamplifier has a lot of gain on tap. With the Gain knob relatively low (e.g., round 9:00), the output exhibited a relatively clean signal with strong second and third harmonics. As the Gain knob was turned up, the distortion products increased significantly, as illustrated in our distortion product plots of Figs. K and L.
One somewhat unique feature of this amp is that the output power is rated at 500 watts regardless of whether the load is 4 ohms or 8 ohms. How does Orange accomplish this feat? Through intelligent limiting. The power amp is definitely capable of putting out 500 watts into 8 ohms, and the impedance switch reprograms the limiter, or otherwise sets an arbitrary peak signal ceiling, when the switch is in the 4-ohm position.
Our tests bear this out. With the switch in the 8-ohm position, the amp output about 500 watts at 8 ohm, with a burst of 637 watts. On the other hand, with the switch at the 4-ohm position, the amp output just over 500 watts, with almost 975 watts burst. The burst output is drastically different for different loads. Also, in our continuous power measurements, we recorded about 62 Vrms at 8 ohms, and approximately 45 Vrms at 4 ohms. Here, you can see that the amp is scaling back the maximum continuous output when the impedance switch is in the 4-ohm position.
Link Removed
