C1 AUDIO FIX - FLOPPY NOISE ISSUES

[exxos]

This fix solves the audio noise issues when accessing the floppy drive.

CURRENTLY THE MIDI AUDIO IS DISABLED (to fix later)


REMOVE THIS CAP

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SOLDER THE REMOVED CAP FROM THE STEP ABOVE ONTOP OF THIS RESISTOR

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CUT TRACK - YELLOW LINE

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SOLDER A 100K 1/8 WATT RESISTOR ACROSS THE POINTS IN YELLOW

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Done!

[exxos]

TRACK CUT ILLUSTRATION

The resistor next to it is only removed for illustration ( do not remove it)

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[exxos]

RESISTOR MOD ILLUSTRATION

IMG_0608.JPG (308.75 KiB) Viewed 5510 times

IMG_0610.JPG (263.69 KiB) Viewed 5510 times

NOTE - The 100K on the right is part of the YM AUDIO FIX MOD

[exxos]

MIDI AUDIO NOISE FIX

You will need to order 2 capacitors. 0805 10uF 10V


CUT THE YELLOW MARKED TRACK

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SOLDER a 10uF ACROSS THIS RESISTOR

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SOLDER A 100K 1/8 WATT (OR 0805) ACROSS THE POINTS IN YELLOW

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RE-SOLDER A 10uF CAP (ASSUMING YOU REMOVED IT IN THE FIRST STEPS)

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[exxos]

Illustration to the MIDI fix.

Cut track.

IMG_0679.JPG (319.62 KiB) Viewed 5387 times

Solder 0805 10uF ontop of the resistor.

IMG_0681.JPG (304.44 KiB) Viewed 5387 times

Add 100K 1/8w across the pads as shown.

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[exxos]

MIDI SYNTH FIX.

(un-verified)

The X2 MIDI audio fix previously was to wire pin 1,2,4, on JP3 prevent audio noise issues when not using the midi synth board.

The fix is advised for the C3 board involves fitting 100K resistors as outlined in the post below.


OLD METHOD - hardwire wire pins 1,2,4, on JP3

JP3.PNG (28.52 KiB) Viewed 5336 times

NEW FIX - Solder 100K 0805 resistors as outlined below.

IMG_0694.JPG (307.93 KiB) Viewed 5336 times

When soldering the resistors angle them outwards slightly and scratch a bit of the GND fill away and solder.

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IMG_0697.JPG (277.92 KiB) Viewed 5336 times

IMG_0699.JPG (249.84 KiB) Viewed 5336 times

[exxos]

Noise example.