Someone explain A/D converters to me

[GamezBond]

Where on an audio interface are they placed How do they improve the sound quality?Would it be useful to buy one for a instrument as a Korg Triton, I really only hear people using A/D converters for Audio interfaces

 

[ds21]

Where on an audio interface are they placed How do they improve the sound quality?Would it be useful to buy one for a instrument as a Korg Triton, I really only hear people using A/D converters for Audio interfaces

I'm no expert, but the basics are:

A/D is the analouge to digital converter, it's how the signal from an outside source that's not digital already and converts it into digital for input into ie: computer,
you'd have to look at the board and know what your looking for to see it.
The don't really improve sound they convert it, though some do it better than others.
Some synths now adays have some form of digital output to directly connect to a PC, if your just using it to hookup to an amp or PA system you wouldn't really need one.

 

[Chibi Nappa]

An A/D converter stands for "analog to digital" converter. You place it in your signal chain at the point where your sound enters the digital world. For example, when you plug a guitar into your computer's soundcard the A/D converter is in the soundcard itself. A keyboard like a Korg Triton might generate it's sounds digitally and have a digital output. In that case, there would be no need for an A/D converter as the information would be digital in the first place. If you use the "regular" outputs on the Korg the sound has to first go through a D/A converter inside of the Korg and then you'd need an A/D converter to get the sound back into a computer.

The short answer is that anytime you record an analog instrument on something digital like your computer, there must be an A/D converter between the instrument and the digital world. All soundcards already have at least a basic A/D converter.

 

[GamezBond]

So the Tritons A/D converters are top notch, and wouldn't benefit from say an apogee 4000$ converter, but an audio interface such as the one that comes bundled in ProTools HD3 would?

 

[fraserhutch]

So the Tritons A/D converters are top notch, and wouldn't benefit from say an apogee 4000$ converter, but an audio interface such as the one that comes bundled in ProTools HD3 would?

Where did you get the the Triton' convertors are top notch? I have personally never even heard of anyone using the Triton's convertors. I didn't even know it had A/D convertors (D/A yes, of course...).

 

[Todzilla]

To me, the easiest way to think of an A/D converter is to imagine a wavelength travelling from left to right along a horizontal axis: ~~~~~~~

An A to D converter essentially maps the position of the wave in timeslices (left to right positions) and amplitude (distance from the mid-line). These positions also correspond to changes in air pressure over time, which is what sound is.

The mapping can get more and more accurate if you make the timeslices thinner and if you make the measurements from the mid-line finer and finer. The timeslices is the sampling rate (e.g., 44.1KHz represents 44,100 slices of time in a single second) and the measurements from the mid-line is the bit-rate (16 bit, 24 bit, etc...).

Thus the A/D device has to first reflect a highly accurate picture of the analog wave. Then, the mapping to digital data is fairly straightforward, although some devices do interesting mathematical modelling in the process of rounding the data when it falls between slices or bit points. The biggest issue though, in my mind, is the representation of the signal to the digitizing process. That's where Lucid, Apogee and others stand apart from the mutt converters.

EEs, you can rightly take me to task on my informal knowledge of electronics. However, I'll think you'll agree that the basic message is sound.

 

[bleyrad]

Then, the mapping to digital data is fairly straightforward, although some devices do interesting mathematical modelling in the process of rounding the data when it falls between slices or bit points.

EVERY oversampling A/D D/A set can figure out with 100% theoretical accuracy what lies between two sampling points (it's basic mathematical wave theory, and it has nothing to do with "rounding" or the "average" between the two points). Higher sampling rates are NOT inherently more accurate (engineer/designer Dan Lavry of Lavry fame makes the claim that higher sampling rates are in fact inherently LESS accurate due to component instability). The only thing they allow you to do is capture higher-frequency sound.

 

[drummersteve]

everybody seems to have stolen the words out of my mouth!

 

[GamezBond]

Ok, in a month, I'm getting promoted to a new spot at work, so I'm gonna purchase Protools HD3, and ASR Sampler to go along with a MPC and Triton, so all I'm going to need to buy a converter is for HD3?I'm going to be tracking at 24 bit 44 khz or 24 bit 48 khz.Thanks

 

[Farview]

With HD, you need to use a pro tools interface. If you get a digital interface, you will need outboard convertors. If you get the analog interface, you won't.

 

[ds21]

P.S. the actuall converters is not the only reason interface "A" sounds better than interface "B" it the whole supporting circuit ie: two sound cards can have the same A/D chip but one could sound better then the other. One thing I've heard is if the clock is more stable in one or if it's locked to a better clock though word clock in, it can make a difference.

 

[Ace_TX]

Ok, in a month, I'm getting promoted to a new spot at work, so I'm gonna purchase Protools HD3, and ASR Sampler to go along with a MPC and Triton, so all I'm going to need to buy a converter is for HD3?I'm going to be tracking at 24 bit 44 khz or 24 bit 48 khz.Thanks

why are you gonna drop so much money on an hd3 system??? that's a ~$13-14k investment just for the dang core+2 accel cards and software and then you still need a control surface and the i/o interfaces...how many tracks are you possibly gonna record to top it off you say your gonna record at 44 & 48khz, ??

your money can be spent much better than that, like on a car or weed or something