Original Concept by:

Hervé Lange, Olivier Cordoléani (BAT, Ubisoft 1989)

Reinvented by:

DoG (Exxos Forum 2021)

Edoardo Auteri (Japan 2023)

BOM list, Centroid files, Schematic, Assembly drawings are provided.

Tested on ATARI ST and STe.

Main Characteristics:

• 12 bit (8 bits x 16 voices/channels) DAC converter with mono OAMP and 7.5kHz LPF.
• It uses the address bus to send the 12 bit sample for conversion.
• Address lines A1-A12 offsetted by the cartridge into available memory space.

Compatible with:

B.A.T.

B.A.T. II

Music Master

Some MOD-Players

Audio Sculpture

Digi Composer

TCB tracker

Noisetracker 1.5

Improvements:

- Reduced form factor.

- Higher noise immunity (ferrite beads and decoupling caps at the power rails, minimized routing and solid ground planes).

- Use of resistor networks at ±0.30% (including tolerance and matching ratio) for a better DAC linearity.

- Option to set 10X gain and bass boost for speakers and headphones.

Note: 2.5X gain is possible with C10 = 10uF + 1.2KΩ resistor (to mount on GAIN/BOOST selector 1-2 position).

- R4 and C11 get connected in

series to give a special

bass effect. Also, the output

gain relies on a bass frequency.

In this case, a 25dB gain

equates to 100Hz, and a

19dB gain equates to 2kHz.

Note: R4 can be either 10KΩ and 100KΩ

for achieving an intense bass boost.

- R3 and C9 enhance a

high-frequency load,

providing stability.

- C13 filters radio interference

picked up by the audio input

connection.

Audio sample (CODE) in the attachment. First half, YM output. Second half, reMV16 output.