SPL Track One Mk3 Channel Strip

Channel Strip from SPL with 1 HU installation height

The SPL Track One Mk3 is a high-quality recording and mixing channel strip with a wide range of processing options for audio signals. For easy operation, there are several high-quality rotary potentiometers and switches on the front panel for setting the desired values and actions.

Functions and controls

The Track One Mk3 has two separate preamps. One is the microphone preamp with 48 V phantom power, which is activated via the 48 V switch, and the other is an instrument preamp. Both pre-amps are designed for a sound-neutral, open and transparent characteristic so that no unwanted aspects are added to the input signal. The microphone pre-amplification can be adjusted from up to 63 dB via the gain control, allowing even demanding microphones to reveal their full quality. Line signals can be pre-amplified in a range of -12 dB and +22 dB, and instrument signals in a range of 0 dB and +35 dB. The"Line/Inst" function offers the option of processing line signals, such as an analog signal from an audio interface, with the effects of the Track One Mk3 and then recording them again. Also located in the pre-amp section is a high-pass filter with the ability to reduce impact sound with 6dB per octave below 80 Hz.

In the de-esser section there is an S-reduction control and an "On" switch for switching the filter on and off. The knob can then be used to reduce disturbing S-sounds on vocal tracks as desired. The S frequencies are detected and mixed with the main signal in a phase-inverted manner, whereby the S frequencies are simply deleted from the main signal and can then no longer be heard or are reduced. If an S-sound is detected, a small LED lights up on the right-hand side of the device. This is only active after switching on the de-esser and works independently of the set reduction value.

The Track One Mk3 also features a compressor/limiter section. To activate this, the "On" switch must first be activated. The compression knob is used to set a threshold value between 0dB and -20dB, which is then used as the upper limit for the compression. If a level exceeds this value, the compressor intervenes and regulates this level peak so that it fits within the defined dynamic range. If the level is reduced, this is shown visually in 1.5 dB increments on the gain reduction display, which is located on the far right of the device. The make-up gain control, on the other hand, raises the level that has been reduced by the overall level reduction caused by compression to the set level. A value from 0 dB to 20 dB can be set, to which the level is raised again after compression. To turn the compressor of the Track One Mk3 into a limiter, it is necessary to press the limiter switch. This switches the device from compression mode to limiter mode, whereby the compression control is still used to control the threshold. The limiter of the Track One Mk3 works as a soft limiter. The attack and release times of the compressor/limiter are set automatically by the device and thus adapt perfectly to the input signal.

The equalizer section of the Track One Mk3 is divided into three sections. Firstly, there is an LMF filter (Low/Mid-Frequencies) with an adjustable frequency range of 30 Hz and 700 Hz, which means that the filter covers all frequencies from the lowest bass range to the lower mid-range. The gain or attenuation of the LMF filter is then determined using the "-/+" rotary control. The maximum values for this setting are +/-12 dB. In addition to the LMF filter, the device also has an MHF filter (Mid/High Frequencies), which has a selectable frequency range of 680 Hz and 15 kHz. Here too, the maximum value of the gain/attenuation is +/-12 dB. If both filters are used simultaneously, the entire frequency spectrum is covered. With the "AIR" filter function, the Track One Mk3 has the option of processing the uppermost frequency range. The filter consists of a coil-capacitor filter with a bell characteristic, with a center frequency of 19 kHz and a possible attenuation/boost of -/+10 dB. To activate the equalizer section, the "On" switch must be flipped.

The last section refers to the output of the device, where the gain knob can be used to attenuate the signal by up to -20 dB or boost it by up to +6 dB. This function ensures that subsequent devices are controlled optimally and not overdriven or too quietly. If an overdriven signal is nevertheless present in the device, this is indicated visually via the "Clip" LED display. The "SIG" LED indicator, on the other hand, lights up when a device with an output level higher than 30 dB is present at the input of the Track One Mk3. The actual display for the output level of the Track One Mk3 takes place via the "PPM output" display, which shows the output level in peak values, which is also used to control the preamplifier level.