Atari Falcon Audio Hardware Cubase Modifications

1To Remove the Bass Boost on the Falcon's Output

Some of the first models of the Atari Falcon 030 incorporated a hardwired bass boost circuitry which interfered with sound monitoring/accuracy.  Obviously, not all Falcon need this mod.

  • Change C58 and C59 from 100PF to 1000PF
  • Change R123 anr R130 from 10K to 15K
  • Change R59 and R68 from 100K to 4.7K
  • Change C95 and C90 from 0.033yF to 1K Resistor

2To Reduce the Speaker Amplifier Gain for Line-level Output

The Atari Falcon 030 lacked a standard line-level output.

  • Add a 100K resistor between pin 2 of U21 (@R119) and AGND (@R111)

3To Reduce the Input Gain by 6dB for Line-level Input

The Atari Falcon 030 originally came with a mic level input.  This made it impossible to connect instruments without excessive noise and distortion.

  • Remove R56, R57, R90, R92, C21 and C81
  • Change R66 and R87 from 100K to 47K. (+) See note below!
  • Add a 470pF NPO +/- 5% in parallel with R67
  • Add a 470pF NPO +/-5% in parallel with R88
  • Add a 100pF NPO +/-5% in parallel with R66
  • Add a 100pF NPO +/-5% in parallel with R87
  • (+)To achive apx. -10db sensitivity, change R66 and R87 from 100K to 1.8K instead of 47K (this is similar to most hi-fi equipment)

4Modification of the CPU-clock Signal

The SDMA is clocked by the 16MHz CPU-clock. In some cases, there may be audio problems such as noise or crackling when recording large sound files to the hard disk; other times, the computer may crash. This is from a timing issue with the clock-signal. If the Falcon 030 has these problems, the following modifications have to be done:

  • Remove SMD resistor R221 (between the CPU and COMBEL)
  • Cut PCB-line left of the R216 (see diagram)
  • Bend the pins of a 74F08 to the outside, except pin 14 Place 74F08 on PAL U63
  • Solder pin 14 of the 74F08 on pin 20 of U63
  • Solder the wires as shown in the diagram below

Atari Falcon CPU-clock Signal Modification