DirectSelect™ Switching Systems

How to Install and Use DirectSelect™ Switching Systems

Introduction

The DirectSelect™ Series of modular switches provides a simple, low-cost solution for many product demonstration and display applications. Its small, tightly focused set of features covers the essentials, avoiding complications associated with competing button-by-the-product systems. If a more comprehensive feature set is needed or if a central control panel is desired, the AccessEZ™ System offers power and flexibility for every application.

The DirectSelect™ Series is comprised of several product-specific models serving a variety of commonly encountered demonstration situations:

• 2951: Stereo mini phone jacks for personal audio sources
• 2952: Stereo RCA jacks for line sources or powered subwoofers
• 2953: Stereo terminal blocks for speakers
• 2954: Stereo terminal blocks for high-level sources
• 2955: Stereo audio + video RCA jacks for A/V sources and VCRs
• 2956: Stereo mini phone jacks for powered speakers
• 2957: Stereo RCA + stereo terminal blocks for receivers and car amps and head units
• 2958: SilenTouch™ plus Master Volume Control
• 2959: Eight pairs of headphones plus SilenTouch™ and Master Volume Control

The DirectSelect™ Series offers a unique set of features aimed at small to mid-size demonstration systems:

• Modules fit the application; add-ons are usually not required.
• Addressing is not required.
• Modules can be used alone, in groups, or in systems.
• Product groups are established by a simple wire cut (see page 9).
• Product Select Buttons (PSBs) are connected with small 2-conductor cable.
• Product deselect capability can be switched on if desired.
• Unique bypass capability does not use a product position.
• Speaker add feature allows two pairs of speakers to be played at once.
• Optional master volume control using the 2958 or 2959.
• Runs on a small, inexpensive DC wall pack or car audio power system.

Modules handle 4 electronic products or 4 pairs of speakers each, except Model 2959, which can power 8 headphones each.

All modules are furnished with 4 PSBs (Product Select Buttons), a 30-inch length of system bus cable, and mounting hardware. 2953, 2954, and 2957 modules also come with a 30-inch length of high-level bus (product connection cables not included). To get your switching system running, you only have to add an 805-021 DC wall pack to home audio systems or a 2994 power block and an 802-314 system DC harness to car audio systems.

How the System Works

The basic principle of DirectSelect™ function is that a new selection automatically deselects the previous selection. The system bus, which interconnects all DirectSelect™ modules, "interlocks" multiple modules so that a new selection on module A will deselect the previous selection, even if it is on module B or C. There are two main exceptions to this principle: multiple product group systems and the speaker add feature.

In systems with multiple product groups, two or more products must be selected at one time in order to demonstrate the system. Therefore, if you select a CD player on module A, you don't want the system to deselect the pair of speakers on module B. Deselect uses the yellow interlock wire in the system bus, so to disable deselect between the CD player product group and the speaker product group, cut the yellow wire in the section of system bus between the groups. Another way to establish product groups is to use a 2958 or 2959 volume control module as the system bus "hub." A separate branch of system bus supplies each product group with power, but only allows deselect within each product group (see page 9).

The speaker add feature is only available on the 2953 speaker module. To enable speaker add, turn ON the Speaker Add dip switch on all speaker modules and power up the system. While one pair of speakers is playing, press and hold the PSB for a second pair of speakers until it is selected. Manually deselect either selected pair by pressing its PSB.

Several other features of the DirectSelect™ system are described in the following examples and in the installation tips on page 9.

Application Examples

Powered Mini Speakers (Figure 1)

In Figure 1, a source such as a CD player or computer with a sound card is used as the sound source for demonstrating computer speakers. Two 2956s are shown bussed together. The system bus cable carries DC power plus an "interlock" signal, and the 3.5mm patch cord carries audio. Interlock causes all other products to deselect when a new product is selected. The only other necessary ingredient for this system is an 805-021 wall pack for power. In this system, the Bypass (product deselect) feature is turned OFF to prevent a silent display.

Diagram Description (Figure 1): Shows two 2956 Powered Speaker Selector modules connected via a System Bus. A "From Source" (e.g., computer or CD player) connects to one module. Powered Mini Speakers (1 of 4 pairs) connect to the other module. Each module has a "Product Select Button [PSB]" and "EXPANSION" ports. The "Bypass Switch" is noted as being OFF, with a note stating that "When Bypass switch is OFF products cannot be manually deselected." An 805-021 Wall Pack provides power.

Personal Electronics (Figure 2)

In Figure 2, personal stereos are selected by a 2951 for play through a dedicated pair of speakers. Turn Bypass OFF so a product is always playing.

Diagram Description (Figure 2): Depicts a 2951 Mini Plug Selector for CD players connected to a Personal CD player (1 of 4). The 2951 module has "Product Select Button [PSB]", "EXPANSION", "BUS IN/OUT", "BYPASS", and "SPK ADD" indicators. It connects to Powered Mini Speakers (1 of 4 pairs). An 805-021 Wall Pack provides power. The "Bypass" is indicated as OFF.

Personal Stereo and Mini Speaker System (Figure 3)

You can also combine the personal stereo application with the mini speaker application to create a new switching system (Figure 3). Notice how the BUS IN/OUT ports of the two groups were connected together to allow the audio signal from personal stereos to go to the speakers. The yellow interlock wire in the System Bus is cut to isolate the two product groups from each other so that selecting a product in one group doesn't cancel the selection in the other group. Bypass is turned OFF on all modules.

Diagram Description (Figure 3): Illustrates two separate product groups connected via a System Bus. The first group has a 2951 Mini Plug Selector for CD players connected to a Personal CD player (1 of 4). The second group has 2956 Powered Speaker Selector modules connected to Powered Mini Speakers (1 of 4 pairs). The instruction "Cut the Yellow wire on the System Bus to establish two separate product groups" is prominent. Each module has "Product Select Button [PSB]", "EXPANSION", "BUS IN/OUT", "BYPASS", and "SPK ADD" indicators. An 805-021 Wall Pack provides power.

Camcorders (Figure 4)

Figure 4 is a simple but very useful application of the 2952 module. The system bus cable is used in this example to allow only one DC wall pack to serve many modules. In every case, the yellow system bus wire is cut to isolate each group of four camcorders from the other groups. Bypass is turned OFF.

For more demonstration power on camcorder displays, use the 2960 camcorder module, which offers theft protection, automatic scanning, and other special features. Contact Audio Authority® for more information.

Diagram Description (Figure 4): Shows multiple 2952 Stereo Audio Modules, each connected to Camcorders (1 of 4) and a "Product Select Button [PSB]" (1 of 4). These modules are connected via a "SYSTEM BUS" and powered by an 805-021 Wall Pack. The instruction "Cut the Yellow wire on the System Bus" is shown for isolating groups. A Video Monitor is connected to one of the groups. Each 2952 module has "EXPANSION", "BYPASS", and "SPK ADD" indicators.

VCRs (Figure 5)

This is a straightforward application of 2955s; the system bus is used only for module DC power distribution. Each 2955 Module dedicates four VCRs to one video monitor. Turn Bypass OFF.

Diagram Description (Figure 5): Depicts multiple 2955 modules, each connected to VCRs (1 of 4) and a "Product Select Button". The "SYSTEM BUS" is used for DC power distribution. A Video Monitor is connected to each 2955 module. The instruction "Cut the Yellow wire on the System Bus" is shown. Each 2955 module has "EXPANSION", "BYPASS", and "SPK ADD" indicators.

Home Audio (Figure 6)

Here's a system for demonstrating multiple CD players, tape decks, stereo receivers, and speakers. The system in Figure 6 is set up to play a CD player except when a tape deck is selected. When the tape deck is deselected, all the tape decks are off, and the CD player is again heard. For this reason, Bypass is turned OFF on all modules except the Tape Deck module so that the tape decks can be turned off to play the CD players. This illustrates how the vacant Bypass port of a group is used to switch in a default signal when every product in a group is deselected. As usual, the yellow system bus wire is cut between product groups.

An optional feature is the ability to record the selected CD player output on any one or all of the tape decks with the addition of an Audio Authority® Model 985 Distribution Amplifier. Contact Audio Authority® for more information.

Diagram Description (Figure 6): Shows a complex home audio setup with CD Players, Tape Decks, Receivers, and Speakers. Multiple 2952 and 2957 modules are interconnected via "SYSTEM BUS" and "Signal Bus". An 805-021 Wall Pack provides power. The "Signal Bus Tip" explains "Signal Bus within a group: Bus to Bypass" and "Signal Bus between groups: Bus to Bus". The instruction "Cut the Yellow wire on the System Bus" is shown between product groups. Modules have "EXPANSION", "BYPASS", and "SPK ADD" indicators.

Subwoofers (Figure 7)

A simple way to boost subwoofer sales is to add this application (Figure 7) to any existing home audio display. You can use 2952 for line-level input subs, 2953 for speaker-level subs, or 2957 to do some of each (4 subs possible per module). Turn Bypass ON to turn subwoofers on and off (deselect). When using 2953 to demonstrate subwoofers, keep the Speaker Add feature turned OFF.

Diagram Description (Figure 7): Illustrates a subwoofer demonstration setup. A 2957 Module (or 2952/2953) is shown connected to a High-Level Subwoofer and a Low-Level Subwoofer via "Low-Level Sub Bus". An 805-021 Wall Pack provides power. The module has "Product Select Button [PSB]", "EXPANSION", "BUS IN/OUT", "BYPASS", and "SPK ADD" indicators. "Bypass" is indicated as ON.

Car Audio (Figure 8)

The system in Figure 8 demonstrates car head units, front amps, and speakers. Head units are wired for both high and low-level through 2957 modules to allow the head units to play either straight through to the speakers or through an amplifier. Bypass is activated on the 2957 amplifier modules so that all of the amps can be turned off (deselected), permitting the head units to drive the speakers directly via the amplifier group's Bypass port.

If desired, Speaker Add may be activated on the 2953 speaker modules to allow two pairs of speakers to play at once. To add the second pair of speakers to the first pair, press and hold the second PSB for the second pair until it is playing along with the first pair. A regular press on either of the active speaker buttons deselects that speaker pair and leaves the other pair on.

DC power from a regulated 13.8-volt source, sufficient for the products being demonstrated, should be distributed by heavy wires to 2994 power blocks where individual products can be connected to receive unswitched DC power. You will find tips on car audio DC power and wiring in the Installation section of this manual.

Diagram Description (Figure 8): Shows a car audio system configuration. 2994 modules are shown providing "POWER SUPPLY" to Head Units and Amplifiers. "Low-Level Signal Bus" connects Head Units to Amplifiers (Bus to Bus). "High-Level Bypass" connects Amplifiers to Speakers (Bus to Bypass). 2957 modules are used for Head Units and Amplifiers, and 2953 modules for Speakers. The instruction "Cut yellow System Bus wire between groups" is shown. Each module has "EXPANSION", "BYPASS", and "SPK ADD" indicators.

EQ System (Figure 9)

Figure 9 shows a system for 4 EQs. It employs 920X modules for the EQs' output.

Diagram Description (Figure 9): Illustrates a system for 4 Equalizers (EQs) using 920XA 2-CHANNEL LOW LEVEL EXPANDER modules. Connections are made via "System Bus" and "Expansion Cable". Buses are labeled "Sub Low-Level Bus", "Rear Low-Level Bus", and "Front Low-Level Bus". A 2952 Stereo Audio Module is shown receiving input from a Head Unit Module and providing output to the EQs. Each module has "EXPANSION", "BUS IN/OUT", "BYPASS", and "SPK ADD" indicators.

Complex Car Audio System (Figure 10)

The system in Figure 10 could switch 8 head units, 8 amplifiers, and 8 speaker pairs. For all buses, observe the "Bus to Bus" rule between groups, but high-level bypass is always "Bus to Bypass" between the head unit and amp groups. Cut the yellow System Bus wire between groups, but leave it intact within each group.

Diagram Description (Figure 10): Depicts a large car audio system. It includes 2957 Modules (Head Units), 2957 Modules (Amplifiers), and 2953 Modules (Speakers). 2994 DC Distribution Modules are used for power. "SYSTEM BUS" and "Low-Level Signal Bus" are shown connecting components. "High-Level Bus (Bus to Bypass)" connects head units to amplifiers. Instructions "Cut the Yellow wire on the System Bus" are shown between groups. "Bypass ON" is indicated. Each module has "EXPANSION", "BYPASS", and "SPK ADD" indicators.

SilenTouch™ and Volume Control (Figure 11)

Any of the illustrated systems can be equipped with a master volume control by adding a 2958 module. As a bonus, the switching interval of DirectSelect™ Series modules will be muted to achieve extremely low switching noise levels. This muting capability, called SilenTouch™, has been a hallmark of Audio Authority® switching technology for over 20 years. Connecting the modules of each of up to three product groups to the 2958 with all yellow wires intact, as shown in Figure 11, activates the SilenTouch feature while logically dividing the product groups.

Diagram Description (Figure 11): Shows systems incorporating a 2958 Volume Control Module. It connects to 2957 Receiver Modules (for Receivers 1 of 8) and 2953 Speaker Modules (for Speakers 1 of 4 pairs). A 2952 Source Module (for CD Player 1 of 4) is also shown. An 805-021 Wall Pack provides power. The instruction "DO NOT cut the Yellow wire on any System Bus cables" is emphasized. The "Signal Bus Tip" clarifies "Signal Bus within a group: Bus to Bypass" and "Signal Bus between groups: Bus to Bus". The 2958 module has "BUS IN", "BUS OUT", "SYSTEM BUS", "Signal Bus", "BYPASS", and "SPK ADD" indicators.

Headphones (Figure 12)

Whether demonstrating multiple headphones with a single source or using a single pair to monitor a product's output, the 2959 fits right in. Besides driving up to 8 pairs of headphones, the 2959 offers the same SilenTouch™ and master volume control facilities as the 2958.

The volume control section of 2958 and 2959 modules may be mounted directly to the back of up to 3/4-inch thick panels to allow ready access to the volume control knob, which operates a durable rotary encoder. Instructions furnished with the 2958 and 2959 explain application of these products in greater detail.

Diagram Description (Figure 12): Illustrates systems using a 2959 Volume Control module with 2952 Source Modules to drive headphones. The 2959 connects to multiple sources (1 of 8). An 805-021 Wall Pack provides power. The instruction "DO NOT cut the Yellow wire on the System Bus" is emphasized. The 2959 module has "SYSTEM BUS", "Signal Bus", "BUS IN/OUT", "BYPASS", and "SPK ADD" indicators, and connections for "HEADPHONES".

Other Switching Applications (Figure 13)

DirectSelect™ Series modules are expandable to allow their switching capability to be increased almost without limit. Connect one or more of the expansion modules listed to a DirectSelect™ module for additional switching capability.

Figure 13 is an example of expanded capacity. A 2952 with a 960X expansion module switches 4 VCRs with S-video capability.

Diagram Description (Figure 13): Shows a 2952 Module for 4 VCRs connected to a 960X S-video Expander via "CASCADE BUS" and "EXPANDER CABLE". A Stereo TV Monitor is connected via "S-video cables" and "Stereo Audio Bus". "Stereo Audio Outputs" are also shown. An 805-021 Wall Pack provides power. The 2952 module has "SYSTEM BUS", "Signal Bus", "BUS IN/OUT", "BYPASS", and "SPK ADD" indicators.

Access™ Expansion Modules:

• 920X: Stereo RCA jacks
• 933X: Stereo mini-phone jacks
• 940X: Stereo terminal blocks
• 950X: Stereo audio + video RCA jacks
• 960X: S-video jacks
• 965X: MATV F-connectors

Multiple Product Groups

Any time more than one group of products is defined in a DirectSelect™ Series system and the 2958 or 2959 is not being used, the yellow wire in the system bus between product groups must be cut in order to set the boundaries of the product groups. For example, say you had three source modules such as 2952, two 2957 receiver modules, and three 2953 speaker modules, but no 2958 (Figure 14). You would run the system bus from module to module, keeping similar product modules grouped together. Then you would cut the yellow wire out of the system bus cable at the boundaries between the groups.

In systems without a 2958 or 2959, the rule is: Leave the yellow wire intact between modules that should cancel one another, cut the yellow wire between modules that should not mutually cancel.

Diagram Description (Figure 14): Shows three product groups: "Source Product Group" (multiple 2952 modules), "Amp/Receiver Product Group" (multiple 2957 modules), and "Speaker Product Group" (multiple 2953 modules). The instruction "Cut the Yellow wire on the System Bus between Product Groups (2 places)" is shown.

Diagram Description (Figure 15): Illustrates systems with a 2958 module. It shows "Source Product Group" (2952 modules), "Amp/Receiver Product Group" (2957 modules), and "Speaker Product Group" (2953 modules) connected to the 2958. The instruction "DO NOT cut the Yellow wire on the System Bus" is shown for the 2958 and between groups. The instruction "DO NOT cut the Yellow wire on the System Bus" is also shown for the 2952 modules within their group.

When using a 2958 or 2959, don't cut any of the yellow wires, but plug each product group of modules into a different System Bus port on the 2958 or 2959. Plug the power pack or DC power input to any available System Bus header (Figure 15).

Installation Tips

Home Audio Installation Tips

Secure DirectSelect™ series modules where they will be protected from damage, such as under a shelf. Standard audio interconnects may be used for RCA-type product hookups and bus connections. 16 or 18 gauge speaker wire is suitable for receiver outputs and speakers. For greater convenience and reliability when installing large systems, replace the individual lengths of system bus cables with AccessEZ™ system bus cable (part number 802-314) and replace the standard high-level bus harnesses with Access™ speaker bus cable (part number 802-186).

Car Audio Installation Tips

Standard audio interconnects may be used for RCA-type product hookups and bus connections. 16 and 18 gauge speaker wire is suitable for amplifier outputs and speakers. For greater convenience when installing large systems and for increased reliability, replace the standard system bus cables with AccessEZ™ system bus cable (part number 802-314) and replace the standard high-level bus harnesses with Access™ speaker bus cable (part number 802-186).

Power Supplies and DC Distribution

Audio Authority® offers the following power supplies to use in car audio displays. Current ratings are continuous DC output:

• 572-012: 5 amps
• 572-005: 10 amps
• 572-010: 12 amps, compact design
• 572-013: 20 amps

Contact your Audio Authority® Account Representative for information about your DirectSelect™ power supply application.

DC Distribution and Wiring

The Model 2994 offers a way to simplify car audio DC wiring. Each 2994 supplies power to four car audio head units or amplifiers; 2994s are bussed together and powered by a common power supply.

Diagram Description (Figure 16): Shows a "Power Supply" connected to a "2994 DC Distribution Module" via "+IGN", "+BAT", "IGN", "BAT" wires. The 2994 module distributes power to a "Head Unit (1 of 4)" and an "Amplifier (1 of 4)" via "Red" and "Yellow" wires. A "System Bus from 2950 Modules" is also shown. The diagram includes "CAUTION! PROVIDE 20A FUSE ON BATTERY" and notes on wire gauge and current ratings.

Protect products and the switching system from damage by placing fuses or other overcurrent protection in DC power wiring. When using a regulated power supply, it will protect downstream wiring that is sized large enough to carry the maximum rated output current of the power supply. For instance, a 20 amp peak power supply will safely protect wiring of 12 AWG or larger. But when in doubt, use a larger wire gauge.

The following table shows recommended wire gauges for protection:

If you encounter any problems installing this product, contact Audio Authority® Technical Service toll-free at 800-322-8346.