Manual Model 9945 Channel Strip Manual Version 1.1 - 5/2000 R & D: Ruben Tilgner Channel One Model 9945 The information in this document has been carefully verified and is assumed to be correct. However Sound Performance Lab (SPL) reserves the right to modify the product described in this manual at any time. Changes without notice. This document is the property of SPL and may not be copied or reproduced in any manner, in part or full without the authorisation of SPL. Limitations of Liability: In no event will SPL be liable for any damages, including loss of data, lost profits, cost of cover or other special, incidental, consequential or indirect damages arising from the use of the unit, however caused and on any theory of liability. This limitation will apply even if SPL or an authorised dealer has been advised of the possibility of such damage. Sound Performance Lab P.O. Box 12 27 D- 41368 Niederkruechten, Germany Phone +49 - 21 63 / 98 34-0 Fax +49 - 21 63 / 98 34-20 eMail: info@soundperformancelab.com www.soundperformancelab.com © 2000 SPL electronics GnbH. All Rights Reserved. Subject to change without notice. 2 Contents Introduction ................................................................................................................... 4 Principles ......................................................................................................................... 4 Hookup ............................................................................................................................. 5 Connections: Rear front / Wiring .......................................................................................................... 6 General advises / Connectors ..................................................................................... 7 Operation: · Preamplifier Microphone Gain, 48 Volt phantom power, phase reverse, high pass ........... 9 Highpass, Instrument Gain, About levelling, Instr./Line On - MicOff, Instr. Input ............................................................................10 · De-Esser On, S-Reduction, Technical Information regarding De-Esser ............................11 · Insert Insert ..................................................................................................................................12 · Compressor/Limiter On .......................................................................................................................................12 Limit, Gain Reduction, Noise Gate ............................................................................13 Make Up, Technical Information regarding the Compressor/Limiter .............14 · Equalizer On, Pre Comp., Air Band ...............................................................................................15 Mid-Hi Band, Cut/Boost (Mid-Hi), Low Band, Cut/Boost (Low) .........................16 Tip for frequency setting, Distortion ........................................................................17 · Output Output, Mute ...................................................................................................................18 · Headphone Monitor Playback, Volume, Phones ...........................................................................................19 · Displays S-Detect., Clip, Signal, Warm Up .................................................................................20 Gain Reduction, PPM-Output .....................................................................................21 Power supply .................................................................................................................21 Specifications ...............................................................................................................22 Block Diagram ..............................................................................................................23 Measurements ..............................................................................................................24 Warranty ..........................................................................................................................26 Copy Master ...................................................................................................................27 Notes .................................................................................................................................28 3 Introduction SPL is mainly known for the development of highly specialized audio-tools. Our philosophy, "one product for one task" is aimed at fast and simple opera, tion in conjunction with high processing quality, to ensure highest musical performance. With Channel One SPL have produced a complete channel strip which for the greater part is based on the processing concepts already successfully realized in other products. The very complex task of a channel strip profits particularly from the innovative techniques that have always allowed the operation of SPL equipment to be efficient and objective. The ususal recording day is to a high degree determined by a series of opposing time limits ­ the "highly paid" singer/speaker desires a quick recording; however, if technical preparation takes a long time because of unsuitable equipment, time will be lost, increasing the costs and souring the working environment. The Channel One in all cases however allows fast production without any loss of professional precision and diligence. The Channel One consists of a transistor/tube pre-amplifier with microphone-, line- and instrumental inputs, a de-esser, a compressor/limiter with noise gate, an equalizer (EQ) section and a headphone monitor. Principles The Channel One has all necessary tools on board to prepare a recording for a digital recording system. It offers many possibilities for sound processing ­ the total bandwidth of subtle corrections to low-fidelity sounds is available. The versatility and completeness of the unit permits its use in additional areas, over and above the purely "recording channel" facility, for instance in mixdown, as high quality single outboard EQ or compressor. To maximize user friendliness and for clarity all modules have been reduced to the most important regulating and switching facilities. Fast and effective operation is in no way impeded, quite the opposite ­ it´s supported. More time remains to work creatively. Great value was placed from the outset on high flexibility. An example of this is the 3 separate inputs for microphone, line-signals or instruments, each of which has been optimized to its function. A twin triode tube is utilized in the process at 2 points ­ one immediately after the amplifier stage and the other at the end of the chain, so that the processed signal passes once again through the tube stage. This construction combines the advantages of the transistor pre-amplifier stage (high performance with minimal distortions and low noise levels) with the improved musical expression of the tone produced by tubes. The microphone input can be optionally provided with Lundahl input transformers. The input transformers deliver a five times enhanced microphone level to the pre-amplifier, an amplification which reduces the equivalent load to the electronic pre-amplifier. The balanced outputs can also be equipped with Lundahl transformers, which deliver an even warmer and fuller sound. 4 Principles A 24 Bit/96 kHz AD/DA module can optionally be provided to enable immediate digital recording.With this AD/DA converter a complete digital insert is also possible. An additional socket on the Channel One serves the purpose of delivering a further signal source to the AD converter. In order to quickly determine all signal conditions, displays for level, gain reduction, S-detection, clip, warm-up and signal are combined and contained in a clearly defined display area. A special feature of the printed circuitry layout is the central star ground wiring scheme: Disturbing influences that could affect the ground paths are minimized in that the audio-ground is separated from the ground of the remaining equipment. This leads, in the truest sense of the word "clean" to considerably , improved tonal quality. The scatter free toroidal transformer, manufactured to SPL tolerances, supplies the equipment with the necessary voltages and forms the basis for a clean electrical supply to all parts of the circuitry. Hookup Carefully select a place for setting up the Channel One. The unit should be situated away from heat sources and direct sunlight. Avoid installation in environments exposed to vibrations, dust, heat, cold or moisture. Keep the unit away from transformers or motors or any other unit that could generate large variations in power supply or cause electrical interferences. Do not install the unit in proximity to power amplifiers or digital processors. You may consider placing it in a rack containing other analog gear. Such placement can prevent interference from Word Clock, Smpte, MIDI, etc. · Do not open the case. You may risk electric shock and may damage your equipment. · Leave repairs and maintenance to a qualified service technician. Should foreign objects fall inside the case, contact your authorised dealer or support person. · To avoid electric shock or fire hazards do not expose your unit to rain or dampness. · In case of lightning unplug the unit. Please unplug the cable by pulling on the plug only; never pull on the cable. · Never force a switch or knob. · To clean the case use a lint-free cloth. Avoid cleaning agents as they may damage the chassis. Manufactured in standard 19" EIA format, it utilises two rack units. · Please support the back of the unit whenever it is being mounted into a 19" rack (especially important when touring). 5 Connections Rear Front / Wiring 6 General Advises Again, while Channel One's housing is EMV-proof and protects against HFinterference, placement of the unit is very important since it amplifies microphone signals as well as other unwanted signals. Before connecting the Channel One or any other equipment turn off all power. Adjust the voltage setting on the back so that it corresponds with the power conditions. The following graph shows the correct wiring for connecting unbalanced signals to the balanced XLR connectors: Connections Unbalanced signals with mono jack plugs may easily be connected to the balanced jack connectors without level differences (see "Analog Outputs" on page 8). Connectors Mic connector The Mic connector is used to plug in microphones of any type (dynamic, condenser or tube microphones etc.). If 48 V phantom power is required for some mics, switch on the 48 V button. For further information please read "48 V-phantom power" on page 9. Connections Line connector The balanced Line connector serves to connect line level equipment. It is recommended to route the Line input to a patchbay. This allows easy and fast selection of various line signal sources. Insert connectors The balanced Insert connectors (Send and Return) are used to integrate further units into the signal path of the Channel One. The Send connector is placed behind the De-Esser, the Return connector is located in front of the Compressor/Limiter. This also allows to record the pre-amplifier signal via the Send connector while another input signal can be fed into the Channel One's Compressor/Limiter/EQ sections for further processing. 7 Connections Analog Outputs Connectors The Analog Outputs deliver balanced output signals. Lundahl output transformers can be equipped optionally. Since both connectors are working in parallel, unbalancing one connector also unbalances the other one. If for example a mono jack plug is connected to the jack connector, the XLR connector is switched to unbalanced operation as well. A/D Input 2 This connector serves to feed a further signal to the optional AD/DA converter. Two different signals can be converted at the same time. If no signal is fed to the A/D Input 2 connector, the output signal of the Channel One is routed to both channels of the converter. The maximum input level should not exceed +12 dBu to avoid clipping of the converter (+12 dBu represents the digital full scale level, 0 dBfs). Playback Inputs The playback signal is connected to the unbalanced Playback Input jacks to direct it to the Headphone Monitor. If a mono playback signal is available, only the Left connector must be connected. The signal will then be present on both channels. The Right connector should be used, if only one channel should appear on one side of the headphones. In contrast to all other connectors the Playback Inputs are unbalanced. GND Lift The GND Lift switch separates internal ground from chassis ground. The switch should be activated to eliminate ground loop humming which may occur if the Channel One is connected to units with another ground potential. 8 Pre-amplifier Operat ...