Crown MPX-6TM manual Overview, Hardware Block Diagram

@crown® * System® Product Reference

MPX-6™Mixer-Router

DSPI ENABLE

120 VAC

AUX

CROWN

BUS

AUDIO

STACK

AUDIO

STACK

AUDIO

ADD 25

AUDIO

ADD 25

AUDIO

ADD 25

AUDIO

ADD 25

AUDIO

ADD 25

AUDIO

ADD 25

60 Hz

SERIAL DATA LOOP

OUT

IN

OUT

IN

IN

0

5 FOR MIC

IN

0

5 FOR MIC

IN

0

5 FOR MIC

IN

0

5 FOR MIC

IN

0

5 FOR MIC

IN

0

5 FOR MIC

CTRL

-5

-5

-5

-5

-5

-5

2 MAIN

1 MAIN

6

-10

10

5

-10

10

4

-10

10

3

-10

10

2

-10

10

1

-10

10

IN

OUT

IN

BUS

BUS

15

15

15

15

15

15

+ –

+ –

-12

21

-12

21

-12

21

-12

21

-12

21

-12

21

20 W

INPUT

M L P

M L P

M L P

M L P

M L P

M L P

+

–

+

–

+

–

+

–

+

–

+

–

+

–

+

–

+

–

+

–

RS232 / RS422 / PA422

GROUND

ONLY

MPX-6COMPUTERCONTROLLEDMIXER-ROUTER (Front Panel shown above, Rear Panel shown below)

OVERVIEW

What is an MPX-6?

The MPX-6 is a single rack space five by one automatic mixer designed to be configured with a computer and appro- priate software. Once initially setup the computer becomes optional. The key to the MPX-6 operating as a stand alone mixer is distributed intelligence™. In an IQ System the brains of the system live out in the system. This means the audio system is not going to be lost even if the computer or communication cables fail. The MPX-6 is an ideal choice for appli- cations where computerized manual mixing or routing is desired and the au- tomation of the SMX-6 or AMB-5 auto- matic mixers is not required.

HARDWARE BLOCK DIAGRAM

Refer to the pictures of the front and rear panels shown above and the block dia- gram of the MPX-6 mixer on Page 2.

Audio Main Inputs:

Six balanced inputs with removable 3 pin barrier block. The preamp stage in- cludes:

• M/L/P switches	AUDIO		ADD 25
set each input to	IN	0	5 FOR MIC
		-5	10
	1
		-10	15
line level (L) with 0
		-12	21
dB gain, mic level			M L P
(M) with 25 dB ad-	+	–
ditional gain, or

phantom (P) which is 25 dB addi- tional gain and +44 VDC phantom power.

•A trim pot at each input allows for prefade gain adjustment of –12 dB to +21 dB gain after the M/L/P switch.

There are two VCAs under processor control at the output of each preamp. One VCA controls the gain from input to output mix 1 and the other VCA controls gain from the input to output mix 2. The net result is 12VCAs total.

Audio Stack Inputs:

Two inputs, one per output mix. Connec- tions are via unbalanced RCA phono jacks. These inputs are op-amp isolated. There is no processor control of audio coming into these inputs. The purpose of the stack inputs is to allow construc- tion of a wide mixer with more than six inputs by taking the outputs of one mixer and going into the stack inputs of a sec- ond mixer. This means that main inputs do not have to be used to expand the

effective size of the overall mixer.
Audio Main Outputs:
There are two summing	AUDIO	STACK
buses. Each summing
	OUT	IN
bus provides the out-	1 MAIN		BUS
put mix for the corre-
sponding output chan-	+ –		+ –
nel. Op-amps buffer
the summing bus to the

output connection and balance the au- dio output. The outputs are via 3 pin re- movable barrier blocks.

Audio Bus Outputs:

In addition to the two main outputs, there are also two bus outputs. Bus outputs 1 and 2 provide the same audio output as main outputs 1 and 2. Op-amps buffer the summing bus to the output connec- tion and balance the audio output. What makes the Bus Outputs different are re- lays under processor control which may be used to turn on or off the Bus Output drive. 3 Pin removable barrier blocks are used.

Aux Port:

The unit is equipped with a TB-3M type mini-XLR port. This port may be used to provide a control signal or sense a con- trol signal. Pin 1 isground reference. Pin 2 is output under processor control. When on it provides 10 VDC at 16 ma. When off it is open collector (high im- pedance). Pin 3 is sensing input. +5 to

+30 VDC is sensed as a logic high. The circuit floats, therefor tie to ground or TTL source for definite high or low.

Indicators:

A Power light on the front panel indicates the unit is powered. A DSPI data signal presence indicator indicates communi- cation.

Crown Bus Port:

The Crown Bus is a serial data loop where components are connected into the loop and one component serves as system interface for all. This unit may serve as a system interface or may sim- ply operate as a component on a Crown Bus data loop. Although the Crown Bus may function on a variety of media, Crown uses a two-wire 20 ma current loop for input and output Crown Bus connections. On this unit connections are made via 4 pin removable barrier block. Even if the unit is communicating directly with a PC via its serial port, it always functions in software as an ad- dressable component on a Crown Bus loop. The unit must have a valid loop address. A valid address is:

•1 to 250 set via 8 segment DIP switch

•No other MPX on the same Crown Bus data loop may have the same address.

The Crown Bus is asynchronous with 8 data bits, 1 start bit, 1 stop bit, no par- ity, and operates at 38400 baud. The MPX is not a U-Code protocol compo- nent.

Serial Port:

The serial port on this unit is a female 25 pin D-Shell. RS232 and RS422 are supported with 8 Data bits, 1 start bit, 1 stop bit, no parity. Up to 19200 baud supported. The serial port for the AMB may be used for direct communication with a PC such that the AMB serves as interface:

MPX-6 Mixer (Page 1 of 3)