STUDIO REPAIR » Studio Electronics » P-Five »  Multiplexer Board     [Image 10 of 15]  :: Jump To  
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Studio Electronics P-Five  •  Multiplexer Board
This is the multiplexer circuit board produced by Studio Electronics for the P-Five. It replaces the complete electronics of the original Prophet-5's panel board.
Studio Electronics P-Five - Top View * Slanted view from above.

Studio Electronics P-Five - Rear View * Rear view - MIDI and cassette I/O, audio out, mains, that's it.

Studio Electronics P-Five - Prophet-5 Voice PCB * An original Prophet-5 voice board (2nd revision with SSM circuits; in the 3rd revision SCI used Curtis chips at last) on top of the P-Five.

Studio Electronics P-Five - Opened * Top cover removed.

Studio Electronics P-Five - CPU Board Removed * The unit had an error on the CPU board so I had to remove it.

Studio Electronics P-Five - Circuit Boards * Front panel PCB and both PCBs mounted on the case's left side are produced by Studio Electronics to fit the Prophet-5 into a rack-mountable format. Really well done!

Studio Electronics P-Five - MIDI Interface * This is the MIDI interface board of the P-Five produced by Studio Eelctronics. In the lower left you can see its Z-80 CPU.
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Studio Electronics P-Five - Multiplexer Board - Image by Nikolaus Riehm - Equipment courtesy of Luca Anzilotti of SNAP!
Studio Electronics P-Five - Power Supply * The original linear regulator is replaced with a modern switched-mode power supply.

Studio Electronics P-Five - Voice Board Butchering * Once upon a time … these two printed circuit boards were one! Here you can see a real curiosity of the P-Five: the original voice board of SCI's Prophet-5 is way to long to fit in a rack-mount case. So Studio Eelctronics choosed the brute forced way - cut it in two halfs and bridge the destroyed traces with direct wiring!

Studio Electronics P-Five - PSU Testing * Testing the P-Five with an external power supply.

Studio Electronics P-Five - Repairing * The CPU PCB had a shortage on the -15V rail so I had to cut some traces sector by sector to insulate the fault.

Studio Electronics P-Five - Test Run * Test-running the P-Five.

 
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