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Lightpipe only 8 channels playback as well???
Old 4 weeks ago
  #1
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Lightpipe only 8 channels playback as well???

I’ve read optical /lightpipe can only handle 8 channels . Does this mean playback or record only or just total 8 tracks only either way.
Here’s what I read on wiki. Thank you!!


Lightpipe can carry eight channels of uncompressed digital audio at 24 bit resolution at 48,000 samples or four channels at 96,000 samples per second. Initially used for the transfer of digital audio between ADATs, the protocol was designed with future improvements in mind. All Lightpipe signals are transmitted at 24 bit resolution, no matter what the depth of the audio; information is contained within the Most Significant Bits and the rest of the bits remain a string of zeros. For example, if a 16 bit signal is sent via Lightpipe, the first sixteen bits contain the audio information while the other eight are simply occupied by zeros. The receiving device ignores information it cannot process. For example, a 20 bit signal going from a Type II ADAT to a Type I (which only operates at 16 bits) will simply ignore the bits below the sixteen MSBs.[3]

Higher sample rates can be accommodated with a reduced number of channels. While the original ADAT machines did not support this, the Lightpipe format was modified using bit-splitting techniques by the company Sonorus. Known as S/MUX (short for 'sample multiplexing'), this connection allows 4 channels at up to 96 kHz, or two channels at up to 192 kHz, on one optical cable. Most manufacturers implementing ADAT Lightpipe now support this S/MUX interface extension.[4]

Light carrying the data signal through the Lightpipe is turned into an electronic data stream going to an IC chip commonly referred to at Alesis as "the 1-K chip". From there the audio data frame is routed to processing IC's.

With an ADAT Lightpipe and an ADAT controller linking up to four ADAT's using CAT5 cables with RJ-connectors and SMPTE Time Code, you could synchronize four 8-track ADATs together for a total of 32 simultaneous synchronized channel tracks of 16 or 20 bit audio data. 24 bit came later with the HD24 Hard Disk recorder in early 2001, which also made use of Lightpipe capabilities.[5]
Old 4 weeks ago
  #2
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Matti's Avatar
One way ticket per pipe

Matti
Old 4 weeks ago
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Quote:
Originally Posted by Matti View Post
One way ticket per pipe

Matti
Mine is 4 optical cables don’t understand

Could I record 4 at a time but ultimately playback mix and bounce more than 8
Old 4 weeks ago
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Ins are ins and outs are outs, if you have 2 outs or ins in a 8 channel device it will transfer 2x4 for higher sample rates

Matti
Old 4 weeks ago
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Quote:
Originally Posted by NoPro View Post
Mine is 4 optical cables don’t understand

Could I record 4 at a time but ultimately playback mix and bounce more than 8
You need to explain what your setup is. Name your devices.
Old 4 weeks ago
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As I understand it, 8 channels of digital audio pushes the edge of the Toslink standard, which is why the 6 meter fiber limit was imposed.

I do not know if using sync via ADAT adds to the datastream or not.

We push 8 channels of 48k, with sync, thru the pipes here, testing regularly with about two minutes of 2k sine wave. Pops and clicks really stand out.

Our 5 and 6 meter Toslinks perform reliably, but the 10 meter, two way pipe we pulled had to be abandoned in place, too noisy.

Jim Williams has reported here, that he gets better performance from glass fiber.
Old 4 weeks ago
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I
Quote:
Originally Posted by stella645 View Post
You need to explain what your setup is. Name your devices.
Apogee element 88 (optical ), Rosetta 800 with sub 25pin to xlr feeding external pres...(want to gain these extra channels with the ext pres)
One device is newer the other not so new.
Im willing to stay at 48k...if i can use unlimited track playback NOT concerned about recording more than 8 channels at a time.
Old 4 weeks ago
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Quote:
Originally Posted by NoPro View Post

.if i can use unlimited track playback NOT concerned about recording more than 8 channels at a time.
Maybe you're confused between number of output channels (limited by hardware) and number of tracks you can play back in your software (only limited by the software)?

You can, of course play back unlimited (if DAW allows) tracks with any hardware...the number of independent physical outs you can access is what would be limited by the lightpipe connection and with these devices is 8 in and 8 out.
Old 4 weeks ago
  #9
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Quote:
Originally Posted by stella645 View Post
Maybe you're confused between number of output channels (limited by hardware) and number of tracks you can play back in your software (only limited by the software)?

You can, of course play back unlimited (if DAW allows) tracks with any hardware...the number of independent physical outs you can access is what would be limited by the lightpipe connection and with these devices is 8 in and 8 out.
Access 8 tracks meaning record at once 8 tracks at 48k regardless of physical inputs....so technically one could record (with the optical lightpipe restriction) 8 tracks , then another 8 tracks etc and etc and same for playback obviously ....this was my question. Does this make sense ? And thank you....
Old 4 weeks ago
  #10
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Lightbulb

Quote:
Originally Posted by NoPro View Post
Access 8 tracks meaning record at once 8 tracks at 48k regardless of physical inputs....so technically one could record (with the optical lightpipe restriction) 8 tracks , then another 8 tracks etc and etc and same for playback obviously ....this was my question. Does this make sense ? And thank you....
If you have both an in and an out you'll be able to do 8 each way at 48k.

If you have two in and two out you should be able to do 16 each way at 48k or 8 at higher sample rate. (Presuming your interface supports it - I'm sure it's got a good manual which would explain all of this)
Old 4 weeks ago
  #11
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Quote:
Originally Posted by NoPro View Post
Access 8 tracks meaning record at once 8 tracks at 48k regardless of physical inputs....so technically one could record (with the optical lightpipe restriction) 8 tracks , then another 8 tracks etc and etc and same for playback obviously ....this was my question. Does this make sense ? And thank you....
You should be able to record 16 tracks at once because you have 8 ins on the Element AND 8 over lightpipe from the 800.
Old 4 weeks ago
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Quote:
Originally Posted by Scumbaguk View Post
If you have both an in and an out you'll be able to do 8 each way at 48k.

If you have two in and two out you should be able to do 16 each way at 48k or 8 at higher sample rate. (Presuming your interface supports it - I'm sure it's got a good manual which would explain all of this)
edit : I see you mentioned 16 tracks at once...that’s great....!!!
Still not an answer but thank you anyway. Let’s try again.
A song/session can or can’t have restricted track count within the sample rate restriction based upon the optical restrictions of lightpipe ??
Eg: record 8 tracks. Hit stop. Record 8 tracks hit stop. Record 8 tracks hit stop. Playback , mix and master 24 tracks

Last edited by NoPro; 4 weeks ago at 07:23 PM.. Reason: Modify
Old 4 weeks ago
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What was wrong with this answer??

Quote:
You can, of course play back unlimited (if DAW allows) tracks with any hardware.
Old 4 weeks ago
  #14
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Quote:
Originally Posted by stella645 View Post
What was wrong with this answer??
I see my fault. Thank you .
It’s fine. The element 88 is a cool device just doesn’t have the dsub25 in/out or this would be a non issue. I find 48k sample rate just awesome for my ears.
Old 4 weeks ago
  #15
Gear Nut
Quote:
Originally Posted by NoPro View Post
edit : I see you mentioned 16 tracks at once...that’s great....!!!
Still not an answer but thank you anyway. Let’s try again.
A song/session can or can’t have restricted track count within the sample rate restriction based upon the optical restrictions of lightpipe ??
Eg: record 8 tracks. Hit stop. Record 8 tracks hit stop. Record 8 tracks hit stop. Playback , mix and master 24 tracks
Obviously when you are playing back your DAW sums all tracks in to one stereo track routed to your speaker so number of in's and out's does not matter.
(unless you're using outboard processing and need to route things in and out while playing back)
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