TTL is just off or on. Analog modulation gives the available lowest power to the fullest power of the laser, controlled via the signals of modulation from the DAC. TTL will yield only 7 color combinations. Analog, depending on DAC and software package, will give you the best color range......a lot more than just 7. Then again it depends on what you are wanting from it and how much $ you have to invest. If you are looking for the best graphics and clean text....Pangolin is the way to go. Search around as there have been many reviews and articles of the like......welcome to the money pit.
You are the only one that can make your dreams come true....and the only one that can stop them...A.M. Dietrich