Using Digital I/O

D

darkecho

New member
My keyboard has a Digital Input and a Digital Output(24-bit S/PDIF I/O). I currently am using the L/R 1/4" Jacks into my interface, but I get some gnarly buzz on occasion due to our airconditioning units I think.

I was wondering if going digital would cut the interference noise down?

If so, i would be getting something simple like this but I am not sure if low quality affects digital as much as analog? should I be getting something with better "converters"? or will this thing even work with a digital keyboard output? The goal is to get max quality out of my expensive keyboard with hopefully no more than 150$... but i would like to be as cheap as possible. Thanks!!!!!
 
it won't work as it only has s/pdif o/p and no i/p.

normally an interface like this shouldn't damage a digital signal too badly, but with digital you're going to have to start considering a bunch of stuff such as wordclock..
 
hmmm....

wordclock eh? I am just simply recording live a single stereo track at a time (sometimes dual mono for panning wide).. is a word clock necessary...

is it because of some weird lag of digital translation?
 
I was wondering if going digital would cut the interference noise down?
Click to expand...

u bet.

If so, i would be getting something simple like this but I am not sure if low quality affects digital as much as analog? should I be getting something with better "converters"? or will this thing even work with a digital keyboard output?
Click to expand...

I would look at a cheap m-audio interface, it will be a little better quality and you know what to expect (i.e. solid drivers) plus that thing has no digital in. Quality analog outs for your monitors is always a plus.

normally an interface like this shouldn't damage a digital signal too badly, but with digital you're going to have to start considering a bunch of stuff such as wordclock..
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Uh, no. SPIDF has its own sync signal built in, you do not need a separate clock
 
Oh Phew! you got me worried there with the word clock haha.

ok so what does affect the signal quality with digital? when does distance becom an issue for the signal strength? what else controls the quality? I am guessing just the converter right?
 
There is no converter since the device is sending in digital, I'm sure there is a limit on length though. You really dont need to worry to much about output converters since the digital audio coming from your keyboard will be as good as it can be
 
Ok awesome, so pretty much anything will work... I just need to find a relatively cheap interface that accepts Digital.. man i wish i had bought the Delta66 instead of the 44 *Doh!* anyone know of anything off the top of their heads that would do a good job? trying to keep it under 100$ if possible... no need for tons of features, i would rather all of that money go into the digital converters. Thanks so much!
 
if i bought the audiophile, I would then have a delta44 and an audiophile in the same computer, would i be able to record simultaneously from both of them?? Thanks!
 
Another thing to try (if you haven't already) before you go digital is to move to balanced cables. I didn't catch what interface you're using with your keyboard, but if both the 1/4" jacks on your keyboard and on your interface accept balanced plugs, and you've been using unbalanced plugs up to this point, try the switch, and see if that helps.

Also, try turning off the AC and/or some lights and see what happens there. If the AC is going in the tracking room, you don't want to pick that up in the mics anyway (if you're also using mics).
 
yueah i would rather take advantage of the digital technology. I have tried turning off the lights, I live with my family so turning off the AC would leave me mortally wounded. I have thought about balanced cables but they seem so expensive at GC that two cables of decent lenght would be just a little less than a new interface..

I actually bought the 99$ e-mu 0404 today and realized that of the two PCI slots i have, the Delta 44 takes up one and my 56k modem card takes the other... anyone know of a way to get a telephone signal into ones Ethernet port?.... arggh!!! WHY!?!

are there any cheap USB interfaces with SPDIF? thank you all very very very much!!!
 
altitude909 said:
Uh, no. SPIDF has its own sync signal built in, you do not need a separate clock
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yeh, no shit ;)



i don't believe i ever mentioned needed a seperate clock. And just because s/pidf has embedded clock does not mean it doesn't bare considering.



:rolleyes:
 
darkecho said:
I have thought about balanced cables but they seem so expensive at GC that two cables of decent lenght would be just a little less than a new interface..
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I'm not sure what cables you've been looking at, but all you need are basic TRS-TRS cables. Hosa makes good one's that are real cheap, something like this:

http://www.musiciansfriend.com/product/Hosa-TRSTRS-Stereo-14-Cable-?sku=333001&src=3WFRWXX

You'd just need two of them, to go between the keboard and the interface, assuming both of those pieces accept balanced cables of course.
 
i don't believe i ever mentioned needed a seperate clock. And just because s/pidf has embedded clock does not mean it doesn't bare considering.
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Why would he have to consider or worry about anything else if his board only has SPDIF?

Try making some sense sometime..
 
Is balanced cable as good as SPDIF?

if it is then I will return my 0404...

is it definately equal in quality? or is it still better to go digital?
 
darkecho said:
Is balanced cable as good as SPDIF?

if it is then I will return my 0404...

is it definately equal in quality? or is it still better to go digital?
Click to expand...

You're mixing your metaphors here.
A Balanced (TRS) 1/4" cable is just that, a cable that is used to transmit analog signals between to devices. The difference between a balanced (TRS) cable and an unbalanced (TS) cable, on a very basic level, is that TRS cables have an extra cable which helps with cancel out noise/hum that can be picked up in the wire.

There are also other types of balanced and unbalanced audio cables, including XLR (balanced) and RCA (unbalanced).

Now, S/PDif (Sony Phillips Digital Interface) is a digital audio transfer protocol. It transmits two channel digital audio using a 75ohm RCA cable, and is self-clocking.

There are also other types of digital audio transfer formats.

My suggestion would be to start by trying out TRS 1/4" cables (again, assuming both your keyboard and interface accept balanced cables), and if it's still noisy, then explore an interface with S/PDif I/O.

Here's a little chart that may be useful. This is not necessarily all inclusive

Analog Audio Connections:
Balanced:
XLR - Pin 1-Ground, Pin 2-Signal(+), Pin 2-Signal(-)
TRS - Tip-Pin 2-Signal(+), Ring-Pin 3-Signal(-), Sleeve-Pin 1-Ground

Unbalanced
TS - Tip-Pin 2-Signal(+), Sleeve-Pin 1-Ground
RCA - Inner Tip - Signal (+), Outer Ring-Ground (not positive on the
terms here, but I think that's the wiring)

Digital Audio Connections:
AES/EBU - 2 channel - Uses XLR Cable.
S/PDif - 2 channel - Uses RCA cable (rated at 75ohm) - Note this is the
same thing as the "Coaxial" audio connection on your DVD player
or other home audio device.
TosLink or Optical S/PDif - 2 Channel - Uses Optical (ADAT) cable.
ADAT - 8 channels - Uses Optical cable.
 
altitude909 said:
Why would he have to consider or worry about anything else if his board only has SPDIF?

Try making some sense sometime..
Click to expand...


do i really have to explain this?




so you're telling me he doesn't need to worry about what sample rate his keyboard is running at and what sample rate his session is running at?


maybe i'm just being a crackhead....
 
i understand how they work.. im asking if one is better than the other for quality

my goal is to open Audition, hit record, and lay down tracks on my keyboard at the highest quality possible, meaning also that there is no noise interferene that I have to use clean up filters for or anything. I want the keyboards pure sound to be captured by my computer. And so far as I know

spdif and TRS get the same sound to the computer, but digital does it with 1's and 0's making it much harder to pick up interference, if not inpossible (unless the interference causes the data to be misread)

anyways, for the most accurate representation of my keyboard with as little interference buzz hum whatever, is digital better?

is there an answer to this question?
 
darkecho said:
spdif and TRS get the same sound to the computer, but digital does it with 1's and 0's making it much harder to pick up interference, if not inpossible (unless the interference causes the data to be misread)
Click to expand...

I guess my point was that s/pdif and TRS don't compare. TRS is a type of cable which transmits an analog signal (mono or stereo). S/PDif is a digital stereo audio transfer protocol which uses an RCA cable.

Probably the best way to answer your question would be to compare. But my guess is that if you have a good quality balanced analog connection, as compared with a good quality digital connection, I'm not sure how much difference you'll hear. Of course, the strength of all your converters is at play here as well.
 
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