1 (edited by UFX_MAN 2011-07-10 11:43:19)

Topic: Adat: Fireface Ufx & Motu Traveler

Hello All

I’m having a few problems with ADAT Audio on the UFX....

System Spec is a Dell M6500 i7 Quad Core, 4GB Ram, WXP SP3 and Cubase 5

We have a MOTU Traveler Mk1 (firmware 1.07 and Latest Cuemix Software) Connected to the UFX (latest Firmware & Software) Via 4 channel ADAT (2 optical Cables 1 in 1 out) also Word Clock Cables Interconnecting both devices and the UFX is Set to Master –

Sync Check is Stating "Sync 88.2kHz" on both Wordclock and ADAT Input 1.

Am using the 4x Microphone Preamps on The UFX and the 4x Mic Preamps of the Motu Traveler.

The traveller's pres are assigned to output on 4 ADAT Mono Channels through the Cuemix Software (this is achieved by panning Mics 1 and 2 to L & R on mix bus 1 and Mics 3&4 Panned L & R on Mix Bus 2) as described by motu.

When we open up Totalmix FX we can See the 4 x individual ADAT Inputs working as expected and when we monitor them directly to the loudspeakers the Traveller's signals appear to sound crisp and clean (though not as crisp as the UFX Preamps wink )

Problem starts when we record.

Using the RME ASIO and a 256 (or above) sample buffer on each device we create 8 Clean Tracks...

Problem really starts when we zoom right in on the timeline...

The tracks recorded from the ADAT Input have an unusual Square wave "carrier frequency" attached the actual shape of the waveform as if it has been poorly sampled? - Usually when you zoom right in you see ascending or descending sample steps..

Then tried the UFX over Firewire (with the Travelers firewire disconnected and running in standalone mode)

Still the same problem....

We tried the Traveler on its own direct via firewire and Waveforms were normal.. thank goodness -

Then Tried the (UFX Asio Driver with the Motu via Adat & WC Slave) sample rate at Single Speed 44.1 kHz - Problem Gone... Also tried the Motu Asio Driver in WC master mode and still no Problem...

In all combinations of these Mixes and matches at 44.1 / 48Khz There appears to be no problems until we enter into 2x & 4x Speed areas where the jitter is very bad.

We then tried running the RME into the Motu Using Matrix to route ch 9 10 11 12 over adat into the motu...

At 88.2 we still have problems - at 44.1kHZ all is ok -

We tried 2 x travelers (1 via adat at 88.2 (4ch) and the waveforms are properly digitised)

Test tones were a simple whistle to create smooth waveforms.

TotalMix does not show any issues when both units connected & Powered on
SyncCheck Reports all to be OK and “Sync”

Any advice would be greatly appreciated -

UFX_MAN

2

Re: Adat: Fireface Ufx & Motu Traveler

There are two possible explanations:

1. You overlooked somewhere to set both units to 88.2 kHz. If one (the UFX?) is still working at 44.1 then you get two samples where there should be only one. Sounds ok but looks strange in a recording (and would play back in half speed).

2. The Traveler uses the SMUXed samples in a wrong order. Second sample is sent first. That would look strange indeed, but not sound too bad as the DAC oversampling filter will remove most of the strange artefacts introduced by such an error.

Google finds this: (Second post)

https://discussions.apple.com/thread/26 … p;tstart=0

Regards
Matthias Carstens
RME

Re: Adat: Fireface Ufx & Motu Traveler

Thanks for your reply Matthias,

1. Both Units are definitely running at 88.2k - and Wavs play back at their real speed - pitch is the same and everything else other than that furry square wave......

2. Hmm could be possible.... but one thing that goes against that is when i output 2 of the travelers channels onto AES XLR into the UFX which Shows "sync" with both AES and ADAT - 88.2k

Yesterday I use the Travelers Cuemix to output the SAME mic channel to both ADAT (mix1) and AES (mix2) the results are interesting...

with one sound source I recorded three seperate wave whistle files - One with Mic10 on ufx , and Two with Analog3 on traveler (split in cuemix) the only channel that had this square wave was the ADAT...  the Traveler AES and UFX Channels were fine -

I then reversed the process with the ufx as slave and motu as asio master and got the same results... AES & Ana3 signal untouched -but ufx adat signal Fuzzed up... Could this problem exist only in the Traveler?

Cant the DDC lock and Steady clock chipsets carry out internal Digital filtering?

If the problem is aliasing in the adat/smux (of which manufacturer?) then is it possible to add an adat smux/anti aliasing function tab within the ufx firmware and software to give better compatibility with other (older) adat manufacturers?

Thanks for your help so far - please let me know what your thoughts are -

UFX_MAN

4

Re: Adat: Fireface Ufx & Motu Traveler

I have the impression that you have not understood my reply, mostly because you don't know what SMUX means. Please read our manuals or google it. If this is an SMUX error then the only solution is a firmware update for the Traveler.

Regards
Matthias Carstens
RME

Re: Adat: Fireface Ufx & Motu Traveler

Thank you - i'll look into it I feel the problem could be with the traveler.. - Hey thanks Matthias, you must think i'm stupid! or you've got out of the wrong side of bed today?... I do have a basic understanding of what smux is - i've just been a bit lazy with its terminology on here.

I'll contact motu and let them know (i'm sure they must be aware of this) come on 1.08 Firmware Motu...

Thanks once again for your time and advice -

UFX_MAN