External Amplifiers; Adding A High-Power Two-Channel Amplifier To A Zone; Installation; Connections And Confi Guration - SpeakerCraft MZC-66 Installation Instructions Manual

Page 28

EXTERNAL AMPLIFIERS

ADDING A HIGH-POWER TWO-CHANNEL AMPLIFIER TO A ZONE

Even though the MZC-66 delivers a solid 30 Watts per Channel of audio power, good enough for most applications, there
may be certain situations when adding a high-power, two-channel amplifi er to a zone will be required. Driving a high power
amplifi er such as the SpeakerCraft BB2125 from a MZC-66 Zone Pre-Out will fi ll a particularly large room with large sound or
provide additional music power poolside for an outdoor zone.
Adding an external zone amp does not require any changes to the 'house' wiring, confi guration or programming of the
zone keypad. The only differences are, the zone speakers get connected to the external amplifi er instead of the MZC-66 and
one stereo RCA-RCA patch cable needs to be connected between the MZC-66 Zone Pre-Out and the Amplifi er Main IN.
When using a SpeakerCraft BB2125, or other SpeakerCraft amplifi er, power management of the external amplifi er is auto-
matic using the on-board audio sensing circuitry. When the amplifi er receives an audio signal from the MZC-66 Zone Pre-Out,
the external amplifi er will turn on automatically. A BB2125, or other SpeakerCraft amplifi er, will shut off after three minutes of
no audio signal. Other makes will vary in their specifi cations and performance. Please refer to appropriate documentation for
additional information.
Some amplifi ers use a 12 volt trigger input to turn on in this type of application (also an option on SpeakerCraft amplifi ers).
There are two methods of 12V control from a MZC-66. One method utilizes the Contact Closure pair as an 'Event' to turn
the amplifi er on and off with a specifi c zone. The other allows use of the MZC-66 Common Status Out. This second option
will have the amplifi er turn on when any zone is on and off when the last zone shuts off. In most cases, turning the external
amplifi er on and off with a specifi c zone is recommended.

INSTALLATION

Additional space should be allocated for installation of an external high-power amplifi er. Leave at least 3-4 inches above
and below the amp for proper air fl ow for cooling. Mounting amplifi ers at the top of an equipment cabinet is recom-
mended to reduce source components exposure to excess heat. Use cooling fans (SpeakerCraft ESC-1) when necessary.
CONNECTIONS AND CONFIGURATION
AUDIO
1. Connect one, quality, RCA-RCA stereo audio patch cable from the appropriate MZC-66 Zone L&R PRE-OUT to the L&R
Main Input on the external amplifi er.
2. Set the VC/NVC Switch to VC (variable). The Zone volume will be controlled via the MZC-66 Zone Preamp using the
Zone Keypad or IR Remote.
SPEAKERS
1. Connect the L+,L-/R-R+ Speaker-level Outputs of the external amplifi er to the appropriate zone speakers.
AUDIO SENSING
1. No additional connections required.
2. If using a SpeakerCraft BB2125, switch the Audio Sense/Trigger/Constant Switch to AUDIO SENSE.
3. If using another brand of amplifi er with audio sensing, please refer to appropriate documentation for additional informa-
tion.
12V TRIGGER (ZONE SPECIFIC)
1. Connect a 12V DC Power Supply (such as the PS-1.0) in series with the MZC-88 Contact Closure as shown in Figure
15. To achieve a faster OFF time action, it may be necessary to place a 1K Ohm,
and white stripped leads of the power supply output, or use a non-regulated power supply.
2. If using a SpeakerCraft BB2125, terminate the control wire with a 3.5mm mini plug and plug it into the Trigger Input
jack. POLARITY: TIP=+12V; SLEEVE=GND. Switch the Audio Sense/Trigger/Constant Switch to TRIGGER INPUT.
3. If using another brand of amplifi er, terminate the control wire as appropriate. Be sure to maintain proper polarity.
4. Confi gure the Contact Closure as an Event for that zone in EZ-Tools. Set the Contact Closure to Close when turning
the zone ON and Open when turning the zone OFF.
MZC-66 Hardware Installation Instructions
1 ⁄ watt resister in shunt with the black
4