from the plug to the power supply cross and actually touch the output signal wires going to the Speakon connectors. This increases the possibility of noise on the output of the amp. Cooling a 1,000-watt amp is always a concern for providing a long, reliable life for the amp. 7KLVXVXDOO\UHTXLUHVDODUJH�f;¿QQHGKHDWVLQN connected to the power amps and power supply. To get the picture shown in Fig. 3 , there was no heat sink to remove. There are, KRZHYHU�f;IRXUVPDOOHU�f;¿QQHGKHDWVLQNVOLQHG up on the left side of the power amp board. The variable-speed fan mounted on the top of the case does blow down directly on these small heat sinks, but that still leaves no heat VLQNRUGLUHFWDLUÀRZRQWKHSRZHUVXSSO\ tasked with supplying power to those large amps. Input The single ¼” input has an impedance of 991 kOhms with a 200Hz sine wave input at 200 mV. This feeds into the Crunch and optical compression circuitry, before heading to the tone stack.The optical compression circuit will compress the higher voltage spikes of the input signal to avoid clipping and even-out the signal. It has an enable button and knob to vary the amount of this effect. More details of this effect are seen in the Gain section of this article. FIG. 5 Optimally ﬂat settings FIG. 6 minimum, minimum Punch, noon, noon Punch, maximum, maximum Punch The Crunch effect shapes many aspects of the signal. It is designed to give an entirely different tone to the amp, and effects can be seen in the tone stack section, as well as the harmonics and gain of the amp. Tone Stack The EQ is advertised as semi-parametric. With the variability that is built in, it is getting close to being a fully parametric EQ. It is 4-band EQ with Low, Lo Mid, Hi Mid, and High controls. The Low band also has a Punch button to increase the bass output even more. The two Mid bands are adjustable for frequency, as well as Q (width), and the High band also has a Bright button to increase the higher frequencies even more. Fig. 4 is the frequency response sweeping all controls of the tone stack. Shown here is a variance of +-35 dB from all-minimum to all-maximum. With all controls at “noon” bass 53 gear FIG. 7 Lo Mid sweep: minimum at low, mid and high frequencies; maximum at low, mid and high Frequencies; Narrow Q minimum at low, mid, and high frequencies; Narrow Q maximum at low, mid and high Frequencies.