exxos's Atari, Amiga & retro forum

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

CURRENTLY THE MIDI AUDIO IS DISABLED (to fix later)


REMOVE THIS CAP



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


CUT TRACK - YELLOW LINE



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


Done!

TRACK CUT ILLUSTRATION

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

RESISTOR MOD ILLUSTRATION


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

MIDI AUDIO NOISE FIX

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


CUT THE YELLOW MARKED TRACK



SOLDER a 10uF ACROSS THIS RESISTOR



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



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

Illustration to the MIDI fix.

Cut track.


Solder 0805 10uF ontop of the resistor.


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

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


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


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

Noise example.