SSL 4000 Patching

ADVANCED RECORDING PRIMER

BY ROBERT DENNIS

SOLID STATE LOGIC PATCHING

Analog full-size consoles have another important feature called the patch bay. The patch bay will contain a connector for all normal inputs and outputs of control room gear. With the patch bay signals can be routed to outboard special effects gear, other tape machines, etc. Every "section" of the console will have input and output jacks for each channel. There will also be jacks to route the signal in the middle of the input section over to special effects gear these jacks are called "insert" or "effects" jacks.

Normals:

Most jacks have switch connections on them called "normals." The usual place the signal would go from that jack is wired through this normal switch. Inserting a patch cord into the jack breaks the normal connection and sends the signal to the jack that you insert the other end of the patch cord to. If you have used a transistor radio that would not play through the speaker when the headphones were plugged in, you have experienced a jack with a "normal."

Figure 1 - Patch Bay Jacks

Normaled and Half-Normaled Jack Pairs:

Figure 1 shows the schematic symbol for a patch point as being a line with a small loop at it's end. Normals are shown as arrows in contact with the line. Patch bays are wired in rows of input jacks below a row of output jacks. The output that would normally feed the input is placed in the row just above the input. These "pairs" of jacks may be independent (have no connection), be normaled (normals wired together) or half-normaled (where the output jack is hard wired to the nomal jack of the input. Most connections in the console's patch bay will be pairs of half-normaled jacks (also called "semi-normaled") .

With the normaled set of jacks, the two normals are wired together. This means that inserting a patch bay cord in either the output or the input jack will break the connection between the jacks.

With the half-normaled (or "semi-normaled) pair of jacks, inserting a patch cord in the output jeck will not break the connection between the jacks. If you, however, insert a patch bay cord into the input jack, the connection will be broken. The output jack is called a "multi" jack because it can feed multiple inputs.

Example Console Patch Bay:

Figure 2 - Top Left Corner Of SSL Example Patch Bay

In our example SSL Console, the first 10 rows of jacks are as follows:

1	Microphone Lines - These are the outputs of the microphones that are plugged into the studio input box.
2	Console Microphone Inputs - Row one is normaled to row 2.
3	Multitrack Returns - These are the outputs of the multitrack recorder.
4	Console Line Inputs - Row 3 is half-normaled to row 4.
5	Channel Input Sends - These are outputs to patch a channel signal to outboard gear.
6	Channel Input Returns - These are inputs to receive back the outboard gear's signal into the channel. Row 5 is half-normaled to row 6 so that the signal will flow through the channel until outboard gear is fully patched.
7	Group Outputs - These are the main multi-channel recording outputs of the console.
8	Multitrack Sends - These are the inputs to the multitrack recorder. Row 7 is half-normaled to row 8.
9	Multitrack Returns - These are the outputs of the multitrack recorder (same signal as in row 3).
10	Tape Monitor Inputs - These are the tape inputs to the monitor channels.

Patching Rules:

There is no "right" way to patch and there are probably different ways you could patch gear to the console, but there are rules. Any patch that works and follows the rules is a "correct" way to patch. A patch that uses less patch cords is usually considered a better patch.

PATCHING RULES
1	Patch an output to an input and patch in the direction of signal flow.
2	Patch points must carry signals of comparable level (e.g., microphone level jacks cannot be patched to line level jacks).
3	Do not patch back to an earlier part of the same channel/chain.
4	One output may be patched to several inputs (usually up to 5).
5	*One input may not* be feed by several outputs.**

Y-Cords, Parallel Jacks:

A Y cord is a cable device with connectors that allow one output to be fed to two inputs at the same time. Patch bays will often have several jacks (3 or 4) wired together that can also be used to send one output to several inputs; these are often referred to as parallel jacks. Two outputs should never be combined using a y-cord or parallel jacks. One output shorts-out the other output when they are connected using a y-cord. Outputs need to be combined by using a console mixing or aux buss.

Common SSL Patches:

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Normally the console's "Group Output" jack (row 7) has the output signal of the recording buss. This jack normals to the "Multitrack Send & Group Monitor Input" jack just below (row 8). This normal connection allows the buss output to feed the track and also feed the monitor channel. When you press the "Direct" button on an SSL channel, the channel signal is sent to the "Group Output" jack and the buss becomes inactive (disconnected). To patch "directly" to a different-numbered track, do the following:

1.	Activate the "Direct Button" on the channel.
2.	Patch from the "Group Output" jack with the same number.
3.	Patch to the "Multitrack Send & Group Monitor Input" with the track number that you desire.

Illustration #3 shows the patching necessary for sending a signal from input 16 to track 9.

Figure 3 - Direct Patch Example

One point that you need to keep in mind is that once you use a Direct button on a channel, the corresponding buss is not able to be used. If you patched Group Out 16 to input 9, buss 16 could not be used to get to track 16. If a situation arises that you need to buss to that disabled track, use a higher-numbered buss and patch it to the track you need. Illustration #4 shows buss number 23 being patched to track 16. Once you have made this patch, any channel you want to get to track 16 needs to be sent to buss 23.

FIGURE 4 - Example of Patching A Buss to Feed Another Track

Much of the patching for outboard gear will be done to patch a device (like a compressor) into the channel's signal path. To do this you patch the Insert Send jack to the unit's input and patch the unit's output back into the Insert Return jack. The Insert Send and Return jacks are not activated until the Insert In button on the channel strip is pushed. The "Insert Pre" button just above the "Insert in" button, will put the patched device in the channel before the equalizer; leaving this button up means the device will be inserted after the equalizer.

This patching configuration, called "in-line" patching, is shown in figure 4.

Figure 5a - Example of In-Line Patching of Gear

Figure 5B - Insert Buttons on SSL Strip For In-Line Patch

Patching Echo Sends & Returns:

The SSL is set up with echo sends (outputs) 1-3 at the left side of the patch bay in row 13. These echo send outputs are fed from the aux busses (1-4) of the console. Row 14 has the inputs to the reverberation devices that the sends normal to. In the RID Teaching console, a Lexicon 200 unit is normaled to echo send 1, a Lexicon 480 L (unit a) is normaled to send 2 and the 480L (unit b) is normaled to send 4. Nothing is normaled to send 3.

The SSL is set up with echo returns 1-4 on the far right side of the patch bay, row 12. Each return is a stereo return with both a "l" and a "RE:" jack. The reverberation device outputs are in the row above the echo return jacks (row 11). In the RID teaching console, the Lexicon 200 is normaled to echo return 1L & 1R; The Lexicon 480L (unit a) is normaled to echo return 2L & 2R, the Lexicon 480L (unit b) is normaled to echo return 4L & 4R.

To patch a different reverb or effects device to the board, patch the echo send to the unit's input and then patch the units outputs to the stereo return jacks with the same number. This is shown in figure 6.

Figure 6 - Patching Echo Send & Returns

Use of Monitor Channel and Small Fader as a Master Echo Send:

It is not uncommon to blend together two or three reverb/effect sounds on different instruments. The blend of effects is important to the sound. If, for instance, you were using three effects to get a good snare reverberation, you would have to move three individual Aux Send controls to raise or lower the amount of reverberation on the snare. A "Master" send from that channel would allow you to move one control for the amount of reverb and use the three individual send knobs to change the blend of the three effects. The small fader can be used for this purpose.

Figure 7 shows the controls/buttons that need to be activated on the SSL strip. At the top of the small fader there is a "From Channel Output" button (see illustration). When this button is pressed, the output of the channel feeds to the small fader. By pressing the Small Fader button next to the Aux Send knobs, the Aux Send controls get their signal from the small fader.

Figure 7 - SSL Setup For Master Sends

Use of Recording Busses For Additional Sends:

It is not unusual to have 8 or ten outboard devices used for effects during a mix. The SSL provides only 4 dedicated aux sends, but an additional send can be used by patching a recording buss to the input of a reverberation or effects device. The monitor channel feeds to the routing matrix in the mix mode. When you set up the monitor channel and small fader to become an echo send master (per figure 7), you can also send it to a recording buss with the output routing matrix. Patching the corresponding "group out" jack to the reverberation device (figure 8) makes the recording buss operate as an echo send. The echo send control is the small fader.

Figure 8 - Using Recording Busses As Additional Sends

Using The Monitor Channel As An Additional Return:

If you are using extra echo/effects devices, these units must return to the stereo mix. The monitor channel and small fader can use used for this also. The jack that connects to the monitor channel is the "Tape Monitor Input" jack (row 10). Patching the output of a reverberation device into a Tape Monitor Input jack will get the signal to the ,onitor channel. To send the signal from the monitor channel to the stereo buss, push "LF" and "RF" in the output routing matrix (The left-fount and right-front busses that are used for the stereo out of the console). Use the small pan in the output routing matrix to pan the return left or right. Figure 9 shows the patching and routing for this.

Figure 9 - Using Monitor Channel As An Additional Return

Using Main Channel Inputs as Additional Returns:

Often the console has more main input than are needed to do the mixdown. If, for instance, you were mixing a 24 track master on a 32 input console, inputs 25-32 would not be needed for the mix. These "extra" channels may be used for echo returns. To do this you patch the output of the reverberation / effects device to the line input of the channel you want to use. For the SSL 4000 the channels should be made "solo-safe" by pulling up on the group trim control knob in the ssl strip for the main channel being used. (See figure 7).