[. . . ] To avoid pain, never put headphones on your head and then plug them in. Always start with the PHONES LEVEL turned down and then turn it up to the desired level. Because of the high current and low output impedance, never short one side to ground or short left and right together as is possible with mono cup headphones. Note: Low power headphone stages typically use large resistors on their outputs, which allow shorting, but prevent high power. [. . . ] Contour Switch PHONO / LINE source select switches are provided for PGM 1 and PGM 2. These are "clickless" switches suitable for "transform scratch" applications. The switches are field replaceable and may be rotated in 45 increments. See Figure 4 on page Manual-6 for rotation and replacement instructions. Program Fader controls for PGM 1 and PGM 2 are ultra low noise, long-life, monorail devices. An ActiveFaderTM design completely isolates the control element from the audio, providing the highest reliability and performance. PGM 1 and PGM 2 Meters provide true L+R Dual Mono indication of Post-Program Fader signal levels. Ten segment resolution is provided with a one second peak hold indication. With the Program Fader set to maximum, the input GAIN TRIM should be set to indicate an average level of about +4. Crossfader control is implemented using Ranes' proprietary ActiveFaderTM design. As with the Program Faders, all audio is isolated from the control element, greatly extending the life and performance of the control. See page Manual-6 for cleaning and replacement instructions CROSSFADER CONTOUR control allows adjusting the "shape" of the Crossfader response from a gentle curve for smooth, long running fades, to the steep pitch required for top performance cut and scratch effects shown in Figure 3. CROSSFADER HAMSTER control allows reversing the operation of the Crossfader. With the combination of ActiveFaderTM, CONTOUR control, and HAMSTER control, the TTM 54 provides a level of flexibility and performance previously unavailable. Figure 3. Crossfader Contour control Manual-3 PHONES LEVEL control adjusts the loudness of the Headphone output signal. Always start with the LEVEL at minimum (CCW) and increase to a comfortable level with signal present and your headphones on. This prevents tossing them across the room after you put them on and plug in with the level set too high. The TTM 54 Headphone Amplifier delivers very high sound pressure levels (SPL) into most headphone loads. Because of the high current and low output impedance, never short one side to ground or short left and right together as is possible with mono cup headphones. Note: Low power headphone stages typically use large resistors on their outputs, which allow shorting, but prevent high power. MASTER / CUE switch is used to select the HEADPHONES monitor source: Use MASTER to rehearse your performance. This signal is the same as that at the MASTER OUT, but is not affected by the MASTER LEVEL control. [. . . ] The MIC INPUT is a balanced input specifically designed for a dynamic microphone. There is no engage switch, so the mic signal is always processed when you have an effects box connected. The RETURN jack provides an input for the signal returning from your effects processor. Adjust the MIC LEVEL so that the OL indicator flashes only when you shout into the microphone. [. . . ]