Equipment information

Lexicon 224X Effect Processor
Manufacturer:
Model:
224X
Date:
1984
Category:
Group:
Description:
Digital Reverb/Effects Processor

Information

As shown in Fig. 3.1, the 224X is divided into 11 major functional modules: 1 Control Head 2 Transition 3 Single-Board Computer (SBC) 4 Nonvolatile Storage (NVS) 5 Timing and Control (T&C) 6 Data Memory (DMEM) 7 Arithmetic Unit (ARU) 8 Floating Point Converter (FPC) 9 Audio Input (AIN) 10 Audio Output (AOUT) 11 Power Supplies (PS1 , PS2, and PS3) for the control head, Transition module, and power supplies, all modules plug into an 8-slot card cage and are interconnected via a motherboard. The card cage and the Power Supply are contained in a mainframe. The control head is connected to the mainframe by a 25-conductor cable. The Timing and Control (T&C), Data Memory (DMEM), and' Arithmetic Unit (ARU) modules comprise a dedicated, 293-ns-cycle, microprogrammed digital signal processor (DSP). During normal operation, signal flow begins with the two audio input channels. The Audio Input (AIN) module filters, samples, and digitizes analog audio signals into .14-bit floating point representations (12-bit mantissa, 2-bit exponent). These floating point representations are then converted into 16-bit fixed-point two’s complement numbers by the Floating Point Converter (FPC) module. The DSP processes this information and generates up to four.independent channels of output data. This processed data is passed back to the FPC module, which reconverts it into floating point form. To generate the audio output, the Audio Output (AOUT) module reconstitutes four analog signals from the digital data stream. The Single Board Computer (SBC) module is a Controller that interfaces the control head to the DSP. The microprocessor (an 8080) on the SBC module scans the switches and pots on the control head and drives the control head displays. It processes the information- received from the control head and changes the program running in the DSP. In addition, the SBC module performs various housekeeping tasks, such as power-up diagnostics and storing and retrieving nonvolatile user setups from the Nonvolatile Storage (NVS) module.

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Service Manual
Manual Type:
Service Manual
Pages:
200
Size:
12.03 Mbytes (12610723 Bytes)
Language:
english
Revision:
Manual-ID:
Date:
1984 01 01
Quality:
Scanned document, all readable.
Upload date:
2017 09 12
MD5:
8d60b3662ff9a87b15d248b624cbe363
Downloads:
890

Information

This service manual for the Lexicon 224X Digital Reverberator has eight sections. Section 1, Introduction, contains a general, description of the 224X and lists the specifications. Section 2, Service/Warranty, gives instructions for periodic maintenance and describes how to return units for service and order parts. In addition, it contains the limited warranty* Section 3, Theory of Operation, including a system overview and describes how each module in the 224X works and how the modules interact with one another. Section 4, Performance Tests and Calibration lists the equipment required for performance tests and describes how to conduct these procedures. l<! Section 5, Troubleshooting, contains troubleshooting procedures, including a discussion of the power supplies; and the diagnostic programs. Section 6, Schematics and Assembly Drawings,contains all 22 4X schematic and assembly drawings. Section 7, Parts List, lists the part number, quantity, description, and reference for all parts.

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