STUDIO REPAIR » Lexicon » PCM 70 - Multi Effects »  Master CPU     [Image 11 of 18]  :: Jump To  
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Lexicon PCM 70  •  Master CPU
Z80 CPU, 6402 UART, RAM
Lexicon PCM 70 - Mainboard * Component side of the large PCM 70 mainboard. It consists of two Z80 CPUs accompanied by three specialized Lexicon high speed processors - they do the number crunching for the audio process algorithms.

Lexicon PCM 70 - Mainboard * Solder side of the PCM 70 main printed circuit board.

Lexicon PCM 70 - Display Reverse * A vacuum fluorescent display (VFD)

Lexicon PCM 70 - Topology * …

Lexicon PCM 70 - Topology * …

Lexicon PCM 70 - LexiChips * The two LexiChips inside the PCM 70 - this is the place where Lexicon's algorithms are forged into silicon…

Lexicon PCM 70 - Memory * Memory management unit with 128 kilobytes of dynamic RAM (organized in 64k x 16bit).

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Lexicon PCM 70 - Master CPU - Image by Nikolaus Riehm
Lexicon PCM 70 - Slave Processor * Z80 CPU accompanied by 16kB static RAM

Lexicon PCM 70 - A/D Converter * …

Lexicon PCM 70 - D/A Converter * Burr Brown PCM53

Lexicon PCM 70 - Analog Circuitry * …

Lexicon PCM 70 - dbx2150 VCAs * Audio output is controlled by two VCAs steered by a separate DAC.

Lexicon PCM 70 - Power Supply * On-board power supply unit

Lexicon PCM 70 - Power Supply * The switched-mode part of the PSU generates the +5V rail for the common digital circuits. The C122 thyristor isn't part of the regulator but a crowbar device safeguarding the +5V power rail against overvoltages. And watch the neat grinding line straight through the ground plane…



 
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