User manual KLARK TEKNIK DN540

[. . . ] DN540 Creative Quad Compressor Operator Manual Klark Teknik, Klark Industrial Park, Walter Nash Road, Kidderminster. Tel: +44 1562 741515 Fax: +44 1562 745371 Email: info@midasklarkteknik. com Website: www. klarkteknik. com DN540 Creative Quad Compressor -- Operator Manual DOC02-DN540 Issue B -- February 2011 © Red Chip Company Ltd. In line with the company's policy of continual improvement, specifications and function may be subject to change without notice. E&OE. IMPORTANT SAFETY INSTRUCTIONS The lightning flash with arrowhead symbol within an equilateral triangle is intended to alert the user to the presence of uninsulated "dangerous voltage" within the product's enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons. [. . . ] No additional time constants are applied to the meter, so that the actual envelope speeds can be easily seen. The gain reduction meter continues to function normally when the DN540 is set in bypass. The bypass indictors are illuminated boldly to signal this fact to the user. 2 Control knob GAIN 3 Control knob RELEASE 4 Control knob PRESENCE 5 6 7 8 Pushbutton LED (orange) Control knob LED meter HARD Not applicable RATIO ATTEN 9 10 Control knob Pushbutton THRESHOLD BYPASS Adjusts the operating point of the compressor. Removes the compressor/dynamic filter from the signal path. 14 DN540 Operator Manual Switch section Item 11 12 Type LED (red) LED meter Label Not applicable LEVEL Function On/off status indicator for the BYPASS pushbutton. The meter has +18dB, +12dB, +6dB, 0dB, -6dB and -12dB LEDs for displaying the output signal level (default). When the MTR I/P pushbutton is on, the meter displays the input signal level. Switch section The switch section has four switches for: changing the compressor mode; switching the signal level meter from output signal to input signal; external sidechain; and channel linking. 8 7 1 2 6 5 Item 1 2 3 4 5 Type LED (green) Pushbutton LED (yellow) Pushbutton Pushbutton Label Not applicable MTR I/P Not applicable LINK EXT Function On/off status indicator for the MTR I/P pushbutton. Switches the LEVEL meter to monitor the output signal (off) or the input signal (on). (There is no LINK button on channel 4. ) When this button is off, the sidechain signals are sourced from the incoming compressor signal, as normal. When this button is on, these signals are sourced from elsewhere via the external sidechain input connector (rear panel). On/off status indicator for the EXT pushbutton. 3 4 6 7 LED (yellow) Pushbutton Not applicable AUTO Selects the compressor mode, where manual mode = off (default) and auto mode = on. On/off status indicator for the AUTO pushbutton. 8 LED (green) Not applicable DN540 Operator Manual 15 Chapter 4: Front Panel 16 DN540 Operator Manual Chapter 5: Rear Panel The rear panel of the DN540 (shown below) has a mains input section and four channel connector sections. Mains input Four channels Note: Although the rear panel of the DN540 has cutouts for two solo bus connectors, these are unused on this unit and are therefore blanked off. Mains input The mains input section has a mains IEC socket, below which is a fuse drawer. Printed just to the right are the mains supply voltage and fuse details. The mains input is an auto voltage sensing, switch mode power supply that operates where normal mains voltage is in the range 100V AC to 240V AC. Mains IEC socket Fuse drawer The fuse drawer houses the mains fuse at the rear of a two-compartment drawer. Always replace the mains fuse with one of the same type of and rating, as printed to the right of the fuse drawer. Channel connector section There are four similar channel sections on the rear of the DN540. Each section comprises a male (output) and a female (input) XLR chassis connector, and a 1/4" TRS connector. These are for connecting to external line level signals, such as a mixing console's insert connections. DN540 Operator Manual 17 Chapter 5: Rear Panel 18 DN540 Operator Manual Chapter 6: Compressor Control Functions This chapter explains the control functions of the DN540 compressor. Attack Attack is the time it takes for the compressor to respond once the threshold has been exceeded. Attack may be set so that the initial transient of the instrument passes through unaltered, or set to a faster value so that the very start of the sound is compressed. Particularly with drum sounds, careful adjustment of attack time can make the sound more punchy and driving. Make up gain As compression reduces the gain (level) of the signal, the gain control lets you add a fixed amount of make up gain, so as to achieve an optimum output signal level. Release Release is the time the compressor takes to recover after the programme material falls back below threshold. Both attack and release also respond to changes in programme level that remains over threshold. For example, a signal that reduces in level but remains above threshold will still trigger a release. However, in this case it will only be a partial release because the compressor is still required to generate gain reduction, albeit for the new lower signal level. Input signal Threshold Signal level Output signal Fast release Input signal Threshold Time Signal level Output signal Slow release Time Figure 2: Compression fast and slow release signal envelope graphs DN540 Operator Manual 19 Chapter 6: Compressor Control Functions Release time plays a very important role in compression. When the signal level falls below the threshold, the gain will increase at a rate determined by the RELEASE control knob. [. . . ] However, in practice the electrical noise on both cables will never be identical, and the degree to which it is reduced is measured by the common mode rejection ratio (CMRR). The electronically balanced input and output connections of the DN540 have the benefit of high common mode rejection (CMR), which eliminates externally induced interference such as mains hum etc. CMR is the ability of a balanced input to reject the part of the incoming signal that has the same amplitude and opposite phase on both input terminals, referenced to ground. As a specification, CMR is usually stated as a dB ratio, called CMRR, at a given frequency. [. . . ]