Hi,
I'm looking for a solution to hook up six dac on one arduino mega. I found the mcp4725 but it semms like i can only hook up 2 devices at the same bus. Is there a simple solution, which is doable for an mechanical engineer ? 
You can use an I2C multiplexer as the PCA9547. With it you get up to 8 distinct I2C buses which you can select with an I2C command. So using the MCP4725 you can have up 16 analog output channels.