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ZOOM F8 Ext Auto Sync (via TC)


Philip Perkins

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(I apologize to JW for starting a new F8 thread, but I have a specific technical question for F8 users and didn't want it buried in the thread with overall impressions and speculations about the recorder's future etc.  If this is not cool I will move this thread or delete and try again there.)

My question is for F8 users--have you used the F8 TC mode in which it uses incoming external TC to control its record (sample) clock?  Have you used this mode over a long take (like a concert set, 1+ hr) and did sync hold with other devices?  There have been other devices (that I've owned) that would do this (MOTU Traveler, Tascam HDP2 among them) and it worked very well, but it isn't something that SD or Zax (or Sax?  Aaton?) recorders do (this is intentional on SD's part at least, they have told me).  So....did this work?  Was the audio glitch free and in sync with whatever?  thx

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  • 2 years later...
On 5/28/2016 at 2:51 PM, Philip Perkins said:

My question is for F8 users--have you used the F8 TC mode in which it uses incoming external TC to control its record (sample) clock?  Have you used this mode over a long take (like a concert set, 1+ hr) and did sync hold with other devices?  There have been other devices (that I've owned) that would do this (MOTU Traveler, Tascam HDP2 among them) and it worked very well, but it isn't something that SD or Zax (or Sax?  Aaton?) recorders do (this is intentional on SD's part at least, they have told me).  So....did this work?  Was the audio glitch free and in sync with whatever?  thx

 

Old post, but I'm wondering the same thing.  I've got an F8n on the way so I'll know soon enough and will file a report.

 

I'll be checking to see if it integrates with a MOTU AVB unit as an aggregate device under macOS when configured for multitrack interface mode with a DAW, and I'm assuming it'll need EXT AUDIO CLOCK SYNC along with LTC feed from the MOTU system.   It'd be a real bonus for my usage list if that works.   

 

I did find one music user who is syncing a pair of F8's for concert remotes, reports no problems, but I don't think he's syncing to video.  He's not tried running as an aggregate interface. 

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On 5/29/2016 at 6:51 AM, Philip Perkins said:

 

My question is for F8 users--have you used the F8 TC mode in which it uses incoming external TC to control its record (sample) clock? 

It does use it to stay in sync with another F8, that I know for sure, as Zoom has confirmed this multiple times. Don't know about the details of if it would work as well with other devices as well other than another F8. 

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Unit in hand, have experimented a little.  I can say it works in aggregate device mode for a short run, can't yet speak to a long run yet.  I only had time to check it with 'drift correction' checked on the Zoom under AudioMIDI with it as secondary slave device, MOTU device as master clock, no time code connection, which leads to:

 

 a response from Zoom customer support which said:

Quote

 

This type of functionality (two F8n in 'multitrack interface mode' or an F8n and another coreaudio compliant device) may be possible, but is not officially supported.

Unfortunately, time code input and output are not available in audio interface mode.

 

 

I hadn't run an aggregate device in several operating systems, and didn't recall the 'drift correction' checkbox, which is apparently a renamed 'resample' option.  I had fed a mono source into each device and recorded for a few minutes.  When I look at the waveforms, there's a latency offset difference that is not corrected on the way in, and once aligned visually to waveform peaks, a phase torch display shows the extreme top frequencies waving back and forth a bit which I believe shows evidence of resampling, as implied by the checkbox.  The two files sound correctly mono with no apparent phasing artifacts when remixed together in mono.  Not wild about the idea of resampling, but then the Mac is doing it in the background all the time and it's never obvious/apparent.  

 

I sent a response suggesting it would be useful in a future update to have time code access in interface mode and/or a word clock option.  I don't really know what hurdles exist on that front.  

 

I'll report in more detail about varied test conditions as I can.

 

 

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On 5/28/2016 at 2:51 PM, Philip Perkins said:

My question is for F8 users--have you used the F8 TC mode in which it uses incoming external TC to control its record (sample) clock?  Have you used this mode over a long take (like a concert set, 1+ hr) and did sync hold with other devices?  There have been other devices (that I've owned) that would do this (MOTU Traveler, Tascam HDP2 among them) and it worked very well, but it isn't something that SD or Zax (or Sax?  Aaton?) recorders do (this is intentional on SD's part at least, they have told me).  So....did this work?  Was the audio glitch free and in sync with whatever?  

 

I have run one experimental pass.  F8n chasing time code from a MOTU 16A, and set for 'external audio clock sync'.   Dual mono fed to the 16A and the F8n.  This works pretty well.  I recorded an hour and ten minutes at 88.2kHz using 30ND LTC, set for ‘External Auto Record’ with ‘External Audio Clock Sync’ on.    The F8n started recording when I hit record in the DAW.  I found initial offset appeared to be low, in the order of a few samples, much better than all other sync attempts.   After correcting the initial offset on the imported file in the DAW, by the end of the recording the offset appeared to be 1.6mS, fine for any mono source, probably fine across a typical multitrack recording, but fails the dual mono remix to mono test with the usual phasing artifacts in mono, or side to side shift with files hard panned opposite.  Phase scope looks very weird, with non-linearities all the way down into low frequencies.  Now if this was only available in interface multitrack mode…..

 

Other tests:

 

F8n sending LTC to the MOTU 16A, significant latency difference and drift within minutes.  The whole system had been warmed up several hours.  The imported WAV file from the F8n did drop into the correct initial time spot.

 

Free sync, no connection between devices, pretty much the same as F8n sending LTC after manual lining up of initial waveform.  

 

Aggregate device with drift correction checked, 2nd test, I found a moment where there was an instantaneous shift in phase linearity, so I wouldn't trust an initial correction to maintain for any amount of time.  This happened about 6 minutes into the experiment, then timing maintained for the next 14 minutes.

 

Aggregate device without drift correction checked, significant latency offset and timing drift within minutes.

 

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