Litepipe arrive when...

[Mondoslug1]

So how close do 8 analog outs & 8 channels thru litepipe converted to analog
arrive at the inputs of a board together? and or how about 8 analog outs and
litepipe going directly into say the litepipe in of an 02R or similar...

[EricK]

Mondoslug1 wrote:
> So how close do 8 analog outs & 8 channels thru litepipe converted to analog
> arrive at the inputs of a board together? and or how about 8 analog outs and
> litepipe going directly into say the litepipe in of an 02R or similar...

Should be within a millisecond or two.

--
Eric

Practice Your Mixing Skills
Multi-Track Masters on CD-ROM
www.Raw-Tracks.com

[EricK]

Mondoslug1 wrote:
> So how close do 8 analog outs & 8 channels thru litepipe converted to analog
> arrive at the inputs of a board together? and or how about 8 analog outs and
> litepipe going directly into say the litepipe in of an 02R or similar...

Should be within a millisecond or two.

--
Eric

Practice Your Mixing Skills
Multi-Track Masters on CD-ROM
www.Raw-Tracks.com

[Steve Jorgensen]

On Fri, 16 Jul 2004 00:05:16 -0500, EricK > wrote:

>Mondoslug1 wrote:
>> So how close do 8 analog outs & 8 channels thru litepipe converted to analog
>> arrive at the inputs of a board together? and or how about 8 analog outs and
>> litepipe going directly into say the litepipe in of an 02R or similar...
>
>Should be within a millisecond or two.

Actually, it's well under 1ms, if I remember correctly. The streams are
interleaved pretty tightly.

[Steve Jorgensen]

On Fri, 16 Jul 2004 00:05:16 -0500, EricK > wrote:

>Mondoslug1 wrote:
>> So how close do 8 analog outs & 8 channels thru litepipe converted to analog
>> arrive at the inputs of a board together? and or how about 8 analog outs and
>> litepipe going directly into say the litepipe in of an 02R or similar...
>
>Should be within a millisecond or two.

Actually, it's well under 1ms, if I remember correctly. The streams are
interleaved pretty tightly.

[EricK]

Steve Jorgensen wrote:
> On Fri, 16 Jul 2004 00:05:16 -0500, EricK > wrote:
>
>
>>Mondoslug1 wrote:
>>
>>>So how close do 8 analog outs & 8 channels thru litepipe converted to analog
>>>arrive at the inputs of a board together? and or how about 8 analog outs and
>>>litepipe going directly into say the litepipe in of an 02R or similar...
>>
>>Should be within a millisecond or two.
>
>
> Actually, it's well under 1ms, if I remember correctly. The streams are
> interleaved pretty tightly.

My interpretation of the question was that the analog signals are going
through A/D conversion to go into a digital board, or the digital signal
is going through D/A conversion to go into an analog board. Either way,
one set of signal is going through conversion, and conversion takes
1-2ms. I read the question as having 16 channels of audio. I think you
are just talking about a litepipe signal.

--
Eric

Practice Your Mixing Skills
Multi-Track Masters on CD-ROM
www.Raw-Tracks.com

[Mike Rivers]

In article > writes:

> So how close do 8 analog outs & 8 channels thru litepipe converted to analog
> arrive at the inputs of a board together? and or how about 8 analog outs and
> litepipe going directly into say the litepipe in of an 02R or similar...

If you're asking about the timing difference between analog and
digital inputs, that depends most on the a/d converter on each one.
For example, the Mackie digital console's analog inputs have a delay
of 32 samples. The delay through their ightpipe-only card is 1 sample.
But in order to compare the two, you have to put an A/D converter
ahead of the lightpipe input, and that's going to have its own delay.

This is something that you ignore if you can, and if you can't (like
you're mixing signals that go through paths with different throughput
delays) you just add delay until you get them lined up so that you
have no comb filtering.

But maybe I didn't understand your question. Were you asking how close
to simultaneous eight channels came out of a lightpipe assuming that they
all went in at the same time? That's something about which I have no
idea. The assumption is that they're close enough to ignore any differences,
which probably means no difference. I don't know if it actually works that
way, but this interface has been around long enough so that if there's a
problem, we'd certianly have heard about it.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Arny Krueger]

"Mondoslug1" > wrote in message


> So how close do 8 analog outs & 8 channels thru litepipe converted to
> analog arrive at the inputs of a board together? and or how about 8
> analog outs and litepipe going directly into say the litepipe in of
> an 02R or similar...

There's really no reason for any timing differences between the channels.

Yes, the digital signals are interleaved at say 48 KHz which is one sample
every 20 microseconds (0.020 milliseconds). However, the same sample clock
is used to sample all 8 channels at the ADC end, so the sampling for all 8
channels is lock-stepped together.

The data rate between the input and output is far greater than 48 KHz so the
idea that there would be 8 sample delays from the first input to the last is
incorrect. But, if there were 8 sample delays there would only be 160
microseconds (0.160 milliseconds) delay. I repeat, there isn't necessarily
any delay among the inputs or outputs because they can easily all be
lock-stepped together.

At the DAC end, again the same sample clock is used to clock out the
reconstructed analog signals. Now, there will be some delay from the point
of conversion to the point of reconstruction, but it can easily be the same
for all channels. AFAIK, it is always is the same for all channels.

Historically, the only time there have been interchannel delays, was when
the same converter was multiplexed to convert more than one channel. In
audio, this generally maxed out at 2 channels and mostly happened a couple
of decades ago. Multiplexing converters was more common when converters cost
lots of money. Today, manufacturers can get pretty fair 24/96 converter
chips for like a buck.

AFAIK, all of the current implementations of lightpipe converters use a
dedicated converter for each channel, input or out. All inputs and outputs
operate in lock step. There are negligable inter-channel delays.

You can find more technical information about lightpipe converters at the
AudioRail web site. They've studied them pretty hard because their product
is heavily dependent on them. No worries about that here!

[Mondoslug1]

Hey thanks for ALL the replys.I knew my wording of the question was not too
coherent...but it was answered by all & in great detail - thanks again.

[Steve Jorgensen]

On Fri, 16 Jul 2004 08:26:57 -0500, EricK > wrote:

>Steve Jorgensen wrote:
>> On Fri, 16 Jul 2004 00:05:16 -0500, EricK > wrote:
>>
>>
>>>Mondoslug1 wrote:
>>>
>>>>So how close do 8 analog outs & 8 channels thru litepipe converted to analog
>>>>arrive at the inputs of a board together? and or how about 8 analog outs and
>>>>litepipe going directly into say the litepipe in of an 02R or similar...
>>>
>>>Should be within a millisecond or two.
>>
>>
>> Actually, it's well under 1ms, if I remember correctly. The streams are
>> interleaved pretty tightly.
>
>My interpretation of the question was that the analog signals are going
>through A/D conversion to go into a digital board, or the digital signal
>is going through D/A conversion to go into an analog board. Either way,
>one set of signal is going through conversion, and conversion takes
>1-2ms. I read the question as having 16 channels of audio. I think you
>are just talking about a litepipe signal.

Yes, I see you are right. I didn't read the question carefully enough.

[Mike Rivers]

In article > writes:

> Hey thanks for ALL the replys.I knew my wording of the question was not too
> coherent...but it was answered by all & in great detail - thanks again.

So what is it that you wanted to know, and more significant, why do
you want to know it?

--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mondoslug1]

Mike R. wrote:

>In article >
writes:
>
>> Hey thanks for ALL the replys.I knew my wording of the question was not too
>> coherent...but it was answered by all & in great detail - thanks again.
>
>So what is it that you wanted to know, and more significant, why do
>you want to know it?
>

Because... I've been interested in sending 8 analog outs & 8 channels via
lightpipe(then converter) from my Digi 001 at the same time and into an analog
board to mix and was curious how much of a delay between the two there was.

I'm not as paranoid about that type of stuff anymore as when I first started
with Digital - no big deal to just nudge them until they feel right.

>--
>I'm really Mike Rivers )
>However, until the spam goes away or Hell freezes over,
>lots of IP addresses are blocked from this system. If
>you e-mail me and it bounces, use your secret decoder ring
>and reach me here: double-m-eleven-double-zero at yahoo
>
>
>
>
>
>

[Wayne]

>Because... I've been interested in sending 8 analog outs & 8 channels via
>lightpipe(then converter) from my Digi 001 at the same time and into an
>analog
>board to mix and was curious how much of a delay between the two there was.
>
>I'm not as paranoid about that type of stuff anymore as when I first started
>with Digital - no big deal to just nudge them until they feel right.
>
>
FWIW, I've been doing just that for a couple of years now. 8 analogue out of
the 001 and 8 out via lightpipe thru a HD24 DAC. Seems to work fine to me.

I'm not crazy about mixing with a mouse and can't afford flying faders and all
that hi dollar stuff, so it's into an analogue desk and back into the HD24.
It's all 24/48 and I'm willing to give up the transfer loss (D/A-A/D) to gain
benefit of the EQ, faders, effects and analogue compressors.

My critical tracks go lightpipe thru the HD24 because the converters sound
better than the 001's. I'm also light piping the outboard analogue inputs thru
the HD24 to the 001 for the same reason. I'm still flipping between HDR's and
DAW's. Trying to grab the best of both worlds, I guess.

Good luck,

--Wayne

-"sounded good to me"-

[EricK]

Mondoslug1 wrote:
> Mike R. wrote:
>>So what is it that you wanted to know, and more significant, why do
>>you want to know it?
>>
> Because... I've been interested in sending 8 analog outs & 8 channels via
> lightpipe(then converter) from my Digi 001 at the same time and into an analog
> board to mix and was curious how much of a delay between the two there was.

You really don't need to worry about any timing differences in your
situation then. The only time it could possible be a problem is if you
split up a stereo pair, and send one side through the analog out, and
the other side through the digital out. Even then, most of the time it
really won't matter. The tiny amount of delay between the two signals
should not have any impact on the music.

--
Eric

Practice Your Mixing Skills
Multi-Track Masters on CD-ROM
www.Raw-Tracks.com

[Mondoslug1]

Eric wrote:

>Mondoslug1 wrote:
>> Mike R. wrote:
>>>So what is it that you wanted to know, and more significant, why do
>>>you want to know it?
>>>
>> Because... I've been interested in sending 8 analog outs & 8 channels via
>> lightpipe(then converter) from my Digi 001 at the same time and into an
>analog
>> board to mix and was curious how much of a delay between the two there was.
>
>You really don't need to worry about any timing differences in your
>situation then. The only time it could possible be a problem is if you
>split up a stereo pair, and send one side through the analog out, and
>the other side through the digital out. Even then, most of the time it
>really won't matter. The tiny amount of delay between the two signals
>should not have any impact on the music.
>
>--
>Eric
>
>Practice Your Mixing Skills
>Multi-Track Masters on CD-ROM
>www.Raw-Tracks.com


Thanks. Was just curious.

[Mike Rivers]

In article > writes:

> ... I've been interested in sending 8 analog outs & 8 channels via
> lightpipe(then converter) from my Digi 001 at the same time and into an analog
> board to mix and was curious how much of a delay between the two there was.
>
> I'm not as paranoid about that type of stuff anymore as when I first started
> with Digital - no big deal to just nudge them until they feel right.


Aha! From the responses, I thought you were asking about the "scatter"
of the eight channels over an ADAT Lightipipe.

When mixing analog intput into some internal A/D converter with
digital intput from some external A/D converter, you really have no
information to go on. But I'd be cautious about sending the same
source through both. Obviously you don't want to send the two channels
of a stereo source through the different paths, but be careful about
leakage. Putting your drum mics through one path and vocal mics with a
lot of drum leakage (live show??) through the other path could give
you comb filtering problems.



--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mondoslug1]

Mike Rivers wrote:


>> ... I've been interested in sending 8 analog outs & 8 channels via
>> lightpipe(then converter) from my Digi 001 at the same time and into an
>analog
>> board to mix and was curious how much of a delay between the two there was.
>>
>> I'm not as paranoid about that type of stuff anymore as when I first
>started
>> with Digital - no big deal to just nudge them until they feel right.
>
>
>Aha! From the responses, I thought you were asking about the "scatter"
>of the eight channels over an ADAT Lightipipe.


Yeah that was something I hadn't even considered.


>When mixing analog intput into some internal A/D converter with
>digital intput from some external A/D converter, you really have no
>information to go on. But I'd be cautious about sending the same
>source through both. Obviously you don't want to send the two channels
>of a stereo source through the different paths, but be careful about
>leakage. Putting your drum mics through one path and vocal mics with a
>lot of drum leakage (live show??) through the other path could give
>you comb filtering problems.

Makes sense.