Ashly 4.24C A Note About Input Signal Levels, D-Sub9 Pin Female RS-232 Pin-Out, MIDI Connections

Operating Manual - PROTEA SYSTEM II 4.24C Crossover / System Processor

A Note About Input Signal Levels:

There are no analog gain trim adjustments on the Protea 4.24C, therefore all the processing (including gain) is done in the digital domain. As a consequence of this design philosophy, it is important to feed the Protea processor with the proper nominal signal level to achieve good signal to noise performance as well as headroom before clipping. The Protea 4.24C is designed to clip at signal levels above +20dBu = 7.75Vrms which places the noise floor lower than -90dBu. The optimum input signal level which should be fed into the Protea processor is 0dBu = .775Vrms. This input level will allow 20dB of headroom while giving a nominal signal that is >90dB above the noise floor.

5.2 MIDI Connections

The Protea family of products include five additional audio processors, the 4.24G Graphic Equalizer/Processor, 2.24S and 4.24S Graphic Equalizer slaves, and 2.24P and 4.24P Parametric Equalizer Slaves. For simultaneous system control of several Protea products which include the 4.24C, it is necessary to use MIDI cables to communicate program changes from the 4.24C to or from other Protea products. The most common instance of Protea MIDI control would be the use of Protea System Software, where a PC connects to one Protea product (through the RS-232 jack) and that unit connects to other Protea units via its Data In and Data Out jacks.

MIDI Pin-Out

31 524

Pin # Function

1NC

2Out & Thru - Ground, In - NC

3NC

4Data +5V

5 Data Signal

MIDI channel assignment within the 4.24C is done in the Util menu, and should match the MIDI channel selected within the crossover section of Protea System Software. Note: If the 4.24C is connected to the PC (RS-232 Dataport) and looped to another unit(s) via both MIDI jacks (Data In/Out), then the RS-232 switch on the back panel must be pushed in. If the 4.24C is any other part of the MIDI chain, or stands alone, the RS-232 switch on the back panel should be left out.

5.3 RS-232 Data Connections

Protea System Software for Windows communicates to the Protea 4.24C via the front panel RS-232 Dataport, using the computer's serial port (usually COM 1-4). COM port assignment is done in the software under the COMMUNI- CATIONS menu, and the 4.24C uses a D-Sub 9 pin female RS-232 connector, fully compatible with a PC serial COM port.

The 4.24C also has an RS-232 mode switch on the back panel which is normally left out. The only time to push in the RS-232 mode switch is when a PC is connected to the front panel RS-232 Dataport, and other units are looped into the back panel Data In and Data Out jacks.

D-Sub 9 Pin Female

RS-232 Pin-Out

5 4 3 2 1

9 8 7 6

Pin # RS-232 DCE Name

1Not Connected

2Transmitted Data

3 Received Data

4 Data Terminal Ready (tied to pin 6)

5Ground

6Data Set Ready (tied to pin 4)

7 Not Connected

8 Not Connected

9 Not Connected

	AC	1/4A Max	On
Ashly Audio Inc.	D igital Audio Products
Made In USA
4. 24C

RS-232

						CAUTION
				Data In	Data Out	Risk of Electric	Standard Mode
5	6	7	8				Multiple Slave Mode
						Shock. Do
				80-240VAC 50-60Hz 20W			(1st Unit Only)
						Not Open

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