By
trupro
Tue Sep 28, 2004 11:10 pm
Analog-to-digital (A-D) and vice versa. That's what they do, exactly.
Takes electrical-based information, and turns it to binary, as in, the analog jacks on his MOTU interface, to get them into computer world.
Then, DA, does it in reverse, such as, on your MPC, when you plug headphones in. The info gets converted from digital to analog, so it can travel down that wire and into the tranciever, to your ears.
An AD coverter is a sampler, taking snapshots of the information; in the
case of a 16 bit MPC2000: 44,100 per second, at 16 bit.
The higher the bit rate, the more samples it can snap off in a second.
Example: ProTools running at 24bit, 96k. That's 96,000 samples-per-second.
The resulting waveform has 'steps' in it, or missing sections of an analog audio wave curve that the A-D converter has sampled. So, the more samples you take, the less space between the steps, the less the machine has to make up for that with 'tricks' (called 'oversampling'), and the closer to 'real sound' you get. This also varies by what you put into it,
but generally speaking, the more a converter costs, the more it can do, and the better it sounds.
Your CD player has a set, so you can hear the digital info on the disc thru speakers. A $20 colby portable has bad coverters when compared to a $400 Denon reference player. I love my ProTools rig, but those converters
are a$$ for input, when matched against Apogee's $1000 a channel interface with the same features.
The theory that details the electrophysics of digital sampling phenomena is called the 'NyQuist Theorum', appropriately named after some scientist with (and I'm making a huge leap of faith here) the last name 'Nyquist'.
Google that Beezach and you'll find alot of cool ish.
