SSL 4000 Console Input/Output Strip

ADVANCED RECORDING PRIMER

BY ROBERT DENNIS

SOLID STATE LOGIC 4000G CONSOLE INPUT/OUTPUT STRIP

The Example Console

The example console is an SSL4000E console frame housing with 4000G modules and computer. It is highly typical of the large-format studio consoles. The console has 32 main inputs and 32 recording buss outputs.

Signal Flow and Status

Like other large-format in-line consoles, the SSL 4000 G has two separate channels running through each of the input/output strips.

The main channel is used as an input channel for microphone signals during recording and during mixdown. The monitor channel is used to mix the track signals for the speakers during recording sessions.

There is one equalizer and one dynamics processor that may be used in either of the channels (but not both at the same time). There are two faders for the two channels. For most status settings the large fader is in the main channel but it is switched to the monitor channel in the "VCA to Monitor" status.

Click on the diagram to the left to see a detailed drawing of the strip.

The SSL has 8 "status" settings. The console status determines the main sequence of the signal flow of the channels, as explained below:

Record Status - Main Channel

The signal path of the main channel is shown in table 1, below when record status (only) is chosen.

TABLE 1 - SIGNAL FLOW OF MAIN CHANNEL IN RECORD STATUS
STEP 1	STEP 2a	STEP 2b	STEP 3	STEP 4a	STEP 4b	STEP 5

(Step 1:) The microphone input signal can be adjusted with the mic gain control; the 48V switch is used to power condenser microphones. (Step 2a:) If the CH button is activated, the signal travels to the equalizer controls . (Step 2b): If one of the CH buttons is activated, the signal travels to the dynamic processing controls - "CH IN" inserts the dynamics processor before the equalizer while "CH OUT" inserts the dynamics processor after the equalizer. (Step 3:) The signal then travels to the large fader . (Step4a:) If the direct button is pushed, the signal is sent directly to the console output with the same number as the module - that recording buss number is deactivated when the direct routing is used. (Step 4b:) The signal will be put on the recording buss according to which number or numbers are pushed in the output routing matrix - the routing panpot will pan between odd and even recording busses if two (an odd and an even) busses are selected with the routing buttons. (Step 5:) The recording buss signal strength can be adjusted with the "group trim" control - the last control before the signal is sent out of the console.

Record Status - Monitor Channel

The signal path of the monitor channel is shown in table 2, below when record status (only) is chosen.

TABLE 2 - SIGNAL FLOW OF MONITOR CHANNEL IN RECORD STATUS
STEP 1	STEP 2a	STEP 2b	STEP 3	STEP 4	DESCRIPTION
					(Step 1:) The monitor channel input comes from the tape machine playback in the "ready tape" position of the monitor input selector - if "ready group" is selected the input is from the console output to the tape machine. Step 2:) (Step 2a:) If the CH button is activated, the signal travels to the equalizer controls . (Step 2b): If the CH button is activated,* the signal travels to the dynamic processing controls. (Step 3:) The signal then travels to the small fader . (Step4:) The signal goes to the mix buss of the console through the L/R panpot - if the "in button is pushed, the signal will panned between front and back mix busses with small F/B panpot.

Record Status With VCA To monitor Status - Main Channel

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The signal path of both the main and the monitor channel is shown in table 3a and 3b below when both record status and VCA to monitor status are selected. The VCA to Monitor Status is usually used by engineers because it is a shorter path and the large faders are usually preferred for mixing.

TABLE 3 - SIGNAL FLOW OF MAIN CHANNEL IN RECORD STATUS WITH VCA TO MONITOR STATUS
STEP 1	STEP 2a	STEP 2b	STEP 3	STEP 4a	STEP 4b	STEP 5

Using VCA To Monitor status along with record status changes the main channel fader to the small fader. The signal flow is: (Step 1:) The microphone input signal can be adjusted with the mic gain control; the 48V switch is used to power condenser microphones. (Step 2a:) If the CH button is activated, the signal travels to the equalizer controls . (Step 2b): If one of the CH buttons is activated, the signal travels to the dynamic processing controls - "CH IN" inserts the dynamics processor before the equalizer while "CH OUT" inserts the dynamics processor after the equalizer. (Step 3:) The signal then travels to the small fader. (Step4a:) If the direct button is pushed, the signal is sent directly to the console output with the same number as the module - that recording buss number is deactivated when the direct routing is used. (Step 4b:) The signal will be put on the recording buss according to which number or numbers are pushed in the output routing matrix - the routing panpot will pan between odd and even recording busses if two (an odd and an even) busses are selected with the routing buttons. (Step 5:) The recording buss signal strength can be adjusted with the "group trim" control - the last control before the signal is sent out of the console.

TABLE 4 - SIGNAL FLOW OF MONITOR CHANNEL IN RECORD STATUS WITH VCA TO MONITOR STATUS
STEP 1	STEP 2a	STEP 2b	STEP 3	STEP 4	DESCRIPTION
					Adding the VCA to monitor status makes the large fader the monitor fader. (Step 1:) The monitor channel input comes from the tape machine playback in the "ready tape" position of the monitor input selector - or from the console output to the tape machine with "ready group." (Step 2a:) If the Mon button is activated, the signal travels to the equalizer controls . (Step 2b): If the Mon button is activated, the signal travels to the dynamic processing controls. (Step 3:) The signal then travels to the large fader. (Step4:) The signal goes to the mix buss of the console through the L/R panpot - if the "in" button is pushed, the small F/B panpot will pan between front and back mix busses.

Replay Status

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The replay status is only used for playback of the take during a recording session. This status affects the signal flow in monitor channel only. (The main channel will have the same signal flow as the record status). Activating this status will make the console monitor channel receive the tape machine playback, even if the "ready group" button is selected, allowing you to hear the tape playback.

Mix Status

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The mix status is used for mixdown. The main channels pick up the line input and the signals are sent to the quad mix buss. The quad buss has 4 channel (left front, right front, left back, right back). The two front channels are used for stereo mixdown. The signal paths for the main and monitor channel are shown below. The main channel is primarily used for the mixdown.

TABLE 5 - SIGNAL FLOW OF MAIN CHANNEL IN MIX STATUS
STEP 1	STEP 2a	STEP 2b	STEP 3	STEP 4	DESCRIPTION
					(Step 1:) The line input signal can be adjusted with the line gain control. (Step 2:) If the CH button is activated, the signal travels to the equalizer controls . (Step 2b): If one of the CH buttons is activated, the signal travels to the dynamic processing controls - "CH IN" inserts the dynamics processor before the equalizer while "CH OUT" inserts the dynamics processor after the equalizer. (Step 3:) The signal then travels to the large fader . (Step4:) The signal goes to the mix buss of the console through the L/R panpot - if the "in" button is pushed, the small F/B panpot will pan between front and back mix busses.

TABLE 6 - SIGNAL FLOW OF MONITOR CHANNEL IN MIX STATUS
STEP 1	STEP 2a	STEP 2b	STEP 3	STEP 4a	STEP 4b	STEP 5

(Step 1:) The monitor channel input comes from the tape machine playback in the "ready tape" position of the monitor input selector - or from the console output to the tape machine with "ready group." (Step 2a:) If the Mon button is activated, the signal travels to the equalizer controls . (Step 2b): If the Mon button is activated, the signal travels to the dynamic processing controls. (Step 3:) The signal then travels to the small fader. (Step4a:) If the direct button is pushed, the signal is sent directly to the console output with the same number as the module - that recording buss number is deactivated when the direct routing is used. (Step 4b:) The signal will be put on the recording buss according to which number or numbers are pushed in the output routing matrix - the routing panpot will pan between odd and even recording busses if two (an odd and an even) busses are selected with the routing buttons. (Step 5:) The recording buss signal strength can be adjusted with the "group trim" control - the last control before the signal is sent out of the console.

Other Console Status Buttons:

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The Quad To Cues status button sends the signal on the mix buss to the musicians' headphones. This means the same mix will be in the control room speakers and the musicians' headphones.

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The Auto Cue status button activates the control room talk circuit to the cue system. This allows the producer or engineer to talk to the musicians throughout the take.

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The status lock button prevents the other status buttons from being changed. This is used for protection during the take.

The Strip Controls

The Input Controls

Click On Control or Button Name For Explanation

The Line Input Gain Control allows adjustment of the input signal strength (usually from the tape machine). The green active indicator shows that this input is active.	The Input Source Flip Button allows making the other input active, overriding the console status. For example, during record status, this button would activate the line input.
	The Sub Group input button deactivates both the Mic and Line input selection and makes the recording buss be picked up by the main console input. The number of the buss is the same as the strip number. If, for example, you pushed this button on strip #10, recording buss 10 would go to this input, rather than to console output 10.
The Mic Input Gain Control allows adjustment of input level for microphone signals. The red active indicator shows that this input is active.	The Polarity ("Phase") Reverse button reverses the electron direction of the input signal. This is referred to as a "phase reverse" even though the input is not delayed by any amount.
	The 48 Volt Phantom Power button causes 48 Volts to be applied to the microphone input connector to power condenser microphones.

The Dynamic Processor Controls

Click On Control or Button Name For Explanation

The Compression Ratio Control sets the compression ratio. Note: Ratios under 10:1 cause compression; ratios 10:1 and above cause Limiting.	The Link Button ties together the control circuit of this dynamics processor with the control circuit of the strip to the right of this strip. This means that the processor will respond to either channel's signal. The Link Indicator shows that this feature is active.
The Compression Release Control sets the time that normal gain will be restored when the signal drops below the compression threshold level.	The Compression Threshold Control sets the level where compression starts. Note: Signals higher than the compression threshold will be compressed.
The Expansion Range Control sets the maximum number of dB gain reduction which will occur with a very low level signal. Pulling up on this control means that the compressor will have fast attack.	The Expansion Threshold Control sets the level where expansion starts. Note: Signals lower than the expansion threshold will be expanded.
The Expansion Release Control sets the time that normal gain will be restored when the signal rises above the expansion threshold level. Pulling up on this control means that the expander will have fast attack.	The Gate Activation Button causes the expansion ratio to go to a gating ratio. Note that without this button pressed, the expansion ratio is 1:2, meaning that for every one dB that the signal falls below the expansion threshold level will cause the gain to be turned down 2 dB. With the gate button activated, the dynamics processor will reduce any signal below the expansion threshold level by the amount determined by the range control.
The Main Channel Input Injection Button puts the dynamics processor in the main channel at the input.	The Gain Reduction Indicators show the amount of gain reduction caused by the compression or expansion. There is a separate indicator for the gain reduction caused by compression and that caused by expansion.
The Main Channel Output Injection Button puts the dynamics processor in the main channel at the output. Note that the dynamics processor comes before the equalizer with "input injection" and after the equalizer with "output injection."	The Monitor Channel Injection Button puts the dynamic processor in the monitor channel. If both the Monitor Channel Injection button is pushed as well as one of the Main Channel Injection Buttons, the processing occurs to the main channel but the sidechain (control circuit) of the dynamics processor is in the monitor channel.

The Equalizer Controls

Click On Control or Button Name For Explanation

The High Pass filter Control sets the cutoff frequency for this filter. Any portion of the signal with frequencies lower than this cutoff frequency will be blocked.	The Low Pass filter Control sets the cutoff frequency for this filter. Any portion of the signal with frequencies higher than this cutoff frequency will be blocked.
The High-Frequency Gain Control sets the amount of gain increase or decrease for the high-frequency band.	The Filter Split Button puts the filters in the main channel, even if the EQ is in the monitor channel.
The High-Mid-Frequency Gain Control sets the amount of gain increase or decrease for the high-mid-frequency band.	The High-Mid-Frequency Extended Range Button makes the high-mid section's frequency multiply by 3.
The High-Mid-Frequency Q Control sets the bandwidth of the high-mid-frequency band.	The High-Frequency Control sets the frequency above which the equalization affects.
The Low-Mid-Frequency Gain Control sets the amount of gain increase or decrease for the low-mid-frequency band.	The High-Mid-Frequency Control sets the center frequency of the High-Mid section of equalization.
The Low-Mid-Frequency Q Control sets the bandwidth of the low-mid-frequency band.	The Low-Mid-Frequency Control sets the center frequency of the Low-Mid section of equalization.
The Low-Frequency Gain Control sets the amount of gain increase or decrease for the low-frequency band.	The Low-Frequency Control sets the frequency below which the equalization affects.
The Main Channel Inject Button inserts the equalizer in the main channel.	The Low-Mid-Frequency Extended Range Button makes the low-mid frequency
The Filters To Dynamic Side Chain Button removes the filter controls from the channel and inserts them into the sidechain (control circuit) of the dynamics processor.	The Monitor Channel Injection Button puts the equalizer in the monitor channel.
The Insert In Button is not an equalizer control, but activates the "insert-return" jack, allowing outboard patched to insert in and insert return jacks to be inserted into the channel.	The Insert Pre Button is not an equalizer control, but places the insert jacks before the equalizer. Not pushing this button leaves the jacks after the equalizer.

The Send Controls

Click On Control or Button Name For Explanation

The Stereo Cue Panpot will pan the signal from this strip for the stereo cue send (for the performing musicians' headphones)	All Send Pre Buttons makes the send signal pick-off point come from before the fader. Not pushing this button leaves the send signal pick-off point after the fader.
All Send Level Controls adjust the amount of the send level. Pushing this control turns on the send; pushing it again turns off the send.	All Small Fader Buttons, chooses which fader's signal will be sent. With this button pushed, the send signal will come from the small fader; otherwise the send signal will come from the large fader.
The Channel Overload Indicator is not a send control, but flashes when the main channel's signal is 4 dB below the clipping point or higher.

Output Controls

The Group Trim Control can reduce the recording buss level when several channels are routed to one recording buss, to prevent overload. Although not an output function, pulling up on the Group Trim knob will cause that large fader to be "solo safe" and not mute when another large fader is soloed.

The Direct Routing Button sends the Main Channel signal directly to the console output to the multitrack channel with the same number. That number recording buss is disabled.

The Float button will send the channel normally assigned to the main mix panpots to the Output Routing Matrix and disable the channel that normally goes to the matrix. In Record Status, the Monitor Channel will be sent to the Output Routing Matrix and the Main Channel is disabled ("floats"). In the Mix Status, the Main Channel is sent to the Output Routing Matrix and the Monitor Channel is "floated."

The Small Fader, Monitor & Mix Controls:

Click On Control or Button Name For Explanation

Monitor Channel Controls
The Ready Group Button makes the Monitor Channel receive the console output signal to the track. Pushing this button or the Tape Ready Button allows the Record Ready Button to function.	The Ready Tape Button makes the Monitor Channel receive the track signals from the multitrack tape machine. Pushing this button or the Group Ready Button allows the Record Ready Button to function.
The Record Ready Button will arm the multitrack tape machine for record ready if either (or both) the Ready Group or Ready Tape Button is pushed.	Note: If both the Ready Group and Ready Tape Buttons are pushed, the monitor channel will receive a mix of both the console output and the tape machine return signals.
The From Channel Input Button makes the Monitor Channel receive its signal from the input of the main channel.	The From Channel Output Button makes the Monitor Channel receive its signal from the Main Channel output (post-fader).
Note: If both the From Channel Input and From Channel Output Buttons are pushed, the Monitor Channel receives its signal from the Main Channel Input after the equalizer.
Small Fader Controls
The Small Fader adjusts gain in the Monitor or Main Channel (depending on the status being used)	The Small Solo button will mute all other small faders.
Note: The Small Solo and Small Cut Buttons always affect the small fader.	The Small Cut Button will mute the channel that the small fader adjusts.
Mixing Panpot Controls
The Front/Back Mix Panpot, if activated, pans the signal between the front and rear main mixing busses.	The F/B Pan In Button activates the Front/Back Mix Panpot.
Note: The Mixing Panpot Controls affect the main channel signal in mix status and the monitor channel signal in record and replay status.	The Left/Right Mix Panpot pans the signal between the left and right main mixing busses.

The Large Fader Controls

Click On Control or Button Name For Explanation

Pushing the Large Solo Button causes all other large faders to mute.	Pushing the Large Cut Button causes this fader to mute.
The Fader Status Button changes the automation status of the fader during automated mixdown operation. The Status Indicators show the automation status that the fader is in.	The Large Fader adjusts the gain of the channel that it is in. Depending on console status, the fader may be in the Main or Monitor Channel
The VCA Group Assignment Switch allows the fader to join any one of the 8 fader groups. The VCA Masters (1-8, in the center of the console) will control gain on the fader groups. If the Fader Group Assignment Button is set to the red "I," it will not be controlled by any master VCA control.

GO ON TO PART 3 - SSL MASTER CONTROLS

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