Hardware version 1

Hardware version 1 has on top these markings:

• 2pin connector on the top left corner of the module which is connected with wires to the main board has "SDA" marking on top
• has only a 4pin connector marked JLINK on the top right
• has a strangely angled resistor soldered to the LED
• no text on the bottom side in the middle of the PLCC socket

Version 1, top side

Version 1, bottom side

Hardware version 2

Hardware version 2 has on top these markings:

• 2pin connector on the top left corner of the module which is connected with wires to the main board has "SCL" marking on top
• has 6 pin connector top right
• 3 components in the bottom part of the top side of the module, with led almost on edge of the board
• text on the bottom "AUDI concert1 chorus 1 volume fix v2.0" in the middle of the PLCC socket

Version 2, top side

Version 2, bottom side

Hardware version 3

Hardware version 3 has on top these markings

• 2pin connector on the top left corner of the module which is connected with wires to the main board has "SCL" marking on top
• has a 6pin connector top right
• 4 components in the bottom part of the top side of the module
• text on the bottom "AUDI concert1 chorus 1 volume fix v3.0" in the middle of the PLCC socket

Version 3, top side

Version 3, bottom side

Hardware version 4

Hardware version 4 has on top these markings:

• 2pin connector on the top left corner of the module which is connected with wires to the main board has "SCL" marking on top
• has 6pin connector top right, with pins description
• 4 components in the bottom part of the top side of the module
• text on the bottom "AUDI concert1 chorus 1 volume fix v4.0" in the middle of the PLCC socket

Version 4, top side with notes

Version 4, bottom side