Manual Channel One Model 2950 Channel Strip
Manual Channel One Model 2950 Version 1.1– 6/2009 This manual contains a description of the product. It in no way represents a guarantee of particular characteristics or results of use. The information in this document has been carefully compiled and verified and, unless otherwise stated or agreed upon, correctly describes the roduct at the time of packaging with this document.
Content Symbols & Notes, Scope of Delivery & Packaging ............................................................ Important Security Information ........................................................................................ Hook Up .......................................................................................................................... Introduction, Principles ................................................................................................... 4 4 5 6 Wiring ...
Symbols and Notes N THIS MANUAL A LIGHTNING SYMBOL WITHIN A TRIANGLE WARNS YOU ABOUT THE POTENTIAL FOR DANGEROUS ELECTRICAL SHOCKS – WHICH CAN ALSO OCCUR EVEN AFTER THE MACHINE HAS BEEN DISCONNECTED FROM A POWER SOURCE. AN EXCLAMATION MARK (!) WITHIN A TRIANGLE IS INTENDED TO MAKE YOU AWARE OF IMPORTANT OPERATIONAL ADVICE AND/OR WARNINGS THAT MUST BE FOLLOWED. BE ESPECIALLY ATTENTIVE TO THESE AND ALWAYS FOLLOW THE ADVICE THEY GIVE.
Important Security Information Lightning: Before thunderstorms or other severe weather, disconnect the machine from wall power (but to avoid life threatening lightning strikes, not during a storm). Similarly, before any severe weather, disconnect all the power connections of other machines and antenna and phone/network cables which may be interconnected so that no lightning damage or overload results from such secondary connections.
Introduction Many audio engineers know SPL’s specialized audio tools, following our philosophy “one product for one task”. This aims at fast and simple operation in conjunction with high processing quality to ensure highest musical performance. With the Channel One we have produced a fully-featured channel strip which for the greater part is based on the processing concepts already known in other products, such as the SPL De-Esser and the DynaMaxx compressor.
1 2 3 3 PUSH 2 1 VOLTAGE | FUSE Pin wiring XLR output sockets: 1=ground, 2=hot (+), 3=cold (-) Pin wiring XLR input sockets: 1=ground, 2=hot (+), 3=cold (-) GND LIFT GND GND LIFT LEFT PLAYBACK INPUTS RIGHT A/D INPUT 2 OUTPUTS Out CONVERTER SERIAL # CHANNEL ONE SERIAL # RETURN In INSERT Effects (delay, reverb, etc.) SPL CONVERTER SLOT – OPTIONAL Console/DAW/Interface Playback 2nd signal source to 2nd channel of the optional converter (e. g.
Rear Panel Sockets and switches Signal connection Switch off the unit before you begin the process of making the first or any subsequent connections. Neglecting this can damage either or both your ears and your equipment. 1/4" TRS sockets The TRS sockets LINE IN, INSERT SEND/RETURN, OUTPUTS und AD INPUT 2 support both balanced (1/4" TRS/stereo jack connector) and unbalanced connections (1/4" TS/mono jack connector). The PLAYBACK INPUTS sockets only support unbalanced connections.
Rear Panel Sockets and switches The rear panel VOLTAGE SELECTOR sets the local line voltage (115 V position: 110-120 volts/6o Hz, 230 V position: 220-240 volts/50 Hz). The diagram to the right shows the correct switch position for 230 V power supply.
Rear Panel Sockets and switches OUTPUTS OUTPUTS The OUTPUTS deliver balanced output signals. An output transformer can be equipped optionally (see page 29). Since both connectors are working in parallel, unbalancing one connector also unbalances the other one. If for example a mono jack connector is plugged into to the jack socket, the XLR socket is operating unbalanced as well. Depending on the impedances of the connected devices, a parallel use of both outputs can reduce the signal level.
Preamplifier Control Elements MIC GAIN The MIC GAIN control determines the level of preamplification. The preamplification values cover a range from +8 dB up to + 68 dB. Further information on page 12, „GAIN adjustments“. If the optional microphone input transformer is installed, the scaled values are to be increased by ca. +14 dB (depends upon microphone, see page 29, “Information on I/O transformers”). 48 V The 48 V switch activates phantom power for condenser microphones with built-in amplifiers.
Control Elements Preamplifier High-pass filter This switch activates the high-pass filter (often also called a “rumble filter”), which operates from 50 Hz downwards with 12 dB/octave. The filter prevents the amplification of unwanted low frequencies. Compared to 6 dB/octave filters, the 12 dB filter works more intensively, thus more effectively – therefore the threshold is set to a low 50 Hz. INSTR.
De-Esser Control Elements ON The first processing module is the de-esser, which removes disturbing sibilants when required. The de-esser module is activated with the ON button. The S-DETECT LED in the display area shows that S-sounds are being detected. It is independent from the S-REDUCTION control and always informs about detected sibilants – attracting your attention to a possible need for regulation (also see „S-DETECT“ on page 22).
Control Elements Insert INSERT The insert button activates any attachments of external equipment for effects, such as delay or reverb, that are connected to the INSERT SEND/RETURN loop on the rear of the Channel One. This binds them into the signal chain, thereby enhancing the processing capabilities ad infinitum. The INSERT point is located between the de-esser and compressor. This allows to use the preamplifier stage/de-esser combination of the Channel One separately from the compressor/ EQ combination.
Compressor Control Elements COMPRESSION The COMPRESSION control sets the intensity of compression. Turning the control clockwise increases compression. The working area spans between 0 dB (fully left) and -32 dB (fully right). The compressor applies the so-called “soft-knee” characteristic, which means it starts processing earlier than with hard-knee curve (see page 26, diagram 1, curve B).
Control Elements Compressor SPL compressor technology In the compressor/limiter section of the Channel One the parameters for the time constants (attack and release) are set automatically and adapt themselves to the changing conditions of the input signal, far better than can ever be achieved by manual adjustments.
Equalizer Control Elements ON The ON button inserts the equalizer/FET distortion module into the signal path. Under normal circumstances the input signal comes from the compressor. With the EQ PRE COMP. button the equalizer can be switched in before the compressor so that the input signal is received from the de-esser or insert. IMPORTANT: To avoid irritations at the beginning of a recording it is recommended to deactivate the equalizer/FET distortion module.
Control Elements Equalizer LMF The center frequency of the half-parametric bass filter is set with the LMF control (low/mid frequencies). The adjustable frequency range lies between 30 Hz and 700 Hz so that this filter covers a range of about 4.5 octaves, allowing it to be used from the deepest bass to the lower mid range. This together with the MHF filter ensures that the entire frequency spectrum is covered.
Equalizer/FET Distortion Control Elements AIR BAND The high frequency filter in the equalizer module is described as the AIR BAND. A coilcapacitor-filter with so called bell characteristics and a center frequency of 17.5 kHz comes into operation here. At this frequency the maximum possible accentuation is +10 dB, the maximum possible damping is -10 dB. The soft and natural tonal property, characteristic of the coil-capacitor filter, lends itself extremely well to provide clarity and ...
Control Elements Output OUTPUT GAIN The outgoing signal can either be dampened to -20 dB or further amplified by +5.5 dB with the OUTPUT control to provide optimal drive to the subsequent units or the optional AD converter. The selected output level is shown on the PPM OUTPUT display in the display field. Before a recording commences the OUTPUT control should be set to 0 dB (12 o’clock position): the uninfluenced values are then legible and available for adjustment of the preamplifiers levels.
Headphone Monitor Control Elements An individual monitoring mix is important for best working conditions and especially a good intonation. That is why the Channel One is equipped with a headphone monitor section, providing a headphone amplifier and a mixing stage to generate an individual mix for the musician with playback and recording signals. In general, the headphone monitor section can of course always serve for direct monitoring of the recording via headphones.
Control Elements Display area All status and level displays are concentrated in a central display area, so all important information can be perceived at a glance. S-DETECT The S-DETECT LED shows when sibilants have been detected. It is only active when the de-esser is switched on, but it is independent from the S-REDUCTION control. So if you turn on the De-Esser, you are always informed about detected sibilants and a possible need for regulation. CLIP The CLIP LED shows overload in the unit.
Display area Control Elements GAIN REDUCT. The GAIN REDUCT. display provides information about the processing being undertaken with the compressor/limiter or the noise gate. The level changes, perhaps caused by compression, are scaled in 1.5 dB steps. The display is activated when the compressor/limiter module is switched on. Noise gate operation is visualized by illumination of all GAIN REDUCT. LEDs when the signal level lies under the gate threshold setting.
Specifications Microphone input Frequency range: (100 kHz = -3 dB) 10 Hz-100 kHz Common mode rejection: (@ -20 dBu) 1 kHz: -80 dB/10 kHz: -78 dB THD & N: Gain: 20 dB 40 dB 65 dB A-weighted: -97,1 dBu -91,1 dBu -69,4 dBu Dynamic range: 118 dB Line/instrument input Frequency range: (-3 dB) 10 Hz-100 kHz Common mode rejection: (@ 0 dBu, LINE IN only) 1 kHz: -80 dB/10 kHz: -78 dB THD & N: Gain: A-weighted: 5 dB -99,4 dBu 20 dB -97,2 dBu 42 dB -79,4 dBu Input impedance: Li
Block diagram Channel One 25
Measurements Compressor/Limiter, Air Band Diagram 1: compressor characteristics Reference curve A displays the relation between input and output. A Curve B shows the curve characteristics of the compressor. The soft knee characteristic is clearly visible. B C Curve C portrays the limiter’s curve characteristics. Diagram 2 shows various cut and boost settings of the air band filter.
Measurements Mid-Hi Filter, Low Filter Diagram 3 displays various cut and boost settings of the MHF filter at 3 kHz. The proportional-Q characteristic is distinctly visible. Diagram 4 displays the curves of the LMF filter. Various cut and boost settings at 150 Hz. Again the proportional-Q characteristic is clearly visible.
Album/Gig: Artist: Date: Track(s)/Groups: Engineer: Copy master: recall settings Title:
Options A/D converter, I/O transformers Please note that you can order products with optional equipment from all dealers, even if they do only list standard product versions, for example in an online store. Please contact your dealer or SPL before you place an order. Optional equipment can also be installed after sales. Available option for the Channel One, model 2950: • 24 bit/96 kHz A/D converter (user installation possible).
Manual Channel One Model 2950
