Consul
Well-known member
It's been a long time since I've been here, but I'm motivated by something fascinating.
Apparently, one of the neater tricks used to get more dynamic range out of early digital telephone systems was to use non-linear resistor ladder DACs. These would essentially cluster the voltage levels toward the lower signals thus spreading the quantization noise out more evenly through the entire volume range.
I'm sitting here thinking I'd like to play around with the idea, and that the values of the resistors in an R2R DAC (just 8 bits) can be modified to fit a mu-law or A-law curve, but every time I think about doing the math to figure it out, my mind reels and I go back to watching old game shows and eating sunflower seeds.
I'm wondering if anyone has any information they can share or point me to on the matter. I've already exhausted Google about as far as I can. The only thing I found of any use was a chapter from a book on digital systems from Analog Semi, and it still left me more confused than informed.
Thank you for your help!
Apparently, one of the neater tricks used to get more dynamic range out of early digital telephone systems was to use non-linear resistor ladder DACs. These would essentially cluster the voltage levels toward the lower signals thus spreading the quantization noise out more evenly through the entire volume range.
I'm sitting here thinking I'd like to play around with the idea, and that the values of the resistors in an R2R DAC (just 8 bits) can be modified to fit a mu-law or A-law curve, but every time I think about doing the math to figure it out, my mind reels and I go back to watching old game shows and eating sunflower seeds.
I'm wondering if anyone has any information they can share or point me to on the matter. I've already exhausted Google about as far as I can. The only thing I found of any use was a chapter from a book on digital systems from Analog Semi, and it still left me more confused than informed.
Thank you for your help!