4Pre and DAT via S/PDIF

[OinkQuack]

I want to back up my old DAT tapes and am using the following hardware:

• Dell Latitude 5520 (Realtek 16-bit soundcard) running Audacity audio software

• Tascam Da-30 MkII

• MOTU 4Pre with power supply

• High quality coax cable

• 1m USB cable

Which are connected thus:

• Tascam DA-30 MkII S/PDIF coax output to MOTU 4Pre S/PDIF coax input

• MOTU 4Pre USB output to Dell Latitude 5520 USB input

The DAT tapes were recorded at 48KHz. Therefore, the Tascam DA-30 MkII on playback is fixed at 48KHz. This means that the Tascam DA-30 MkII is the clock master and the MOTU 4Pre must be a slave, hence I have set the MOTU console clock source to S/PDIF.

• If I set the MOTU console bit rate to 48KHz and clock source to S/PDIF (the ideal), Audacity sees the MME MOTU S/PDIF, but shows a hardware error when trying to record:

-9999 Unanticipated host error: this means means "something is wrong". And appears to most often be due to either:
A lost connection to a USB audio device.
Recent Windows / Mac update requiring that user gives permission for Audacity to access the microphone.

I have disabled any system interruptions or power-downs of USB, but have not checked the permissions. However, Audacity sees the MOTU 4Pre S/PDIF and will record under certain circumstances. So, it seems unlikely to be a permissions issue.

• If I set the MOTU console bit rate to 48KHz and the clock source to internal, then the MOTU 4Pre shows 48KHz constantly lit, but 44.1KHz flashing, and Audacity records, but with dropouts and syncing issues.

• If I set the MOTU console bit rate to 44.1KHz and the clock source to S/PDIF, Audacity records but with with that grainy bitty sound, like a low quality sample.

• I haven't tried setting the MOTU console bit rate to 44.1KHz and the clock source to internal.

I got so frustrated that I recorded the tapes from the Tascam's analogue outputs into a Zoom H4N 24-bit audio recorder and the results are fine, but this is my last opportunity to get a digital copy of the tapes and I would really appreciate any input to solve this.

Thanks

[CharlzS]

Try using something other than Audacity - something that uses the ASIO driver. If you don't already own a DAW/audio recording software that uses ASIO, you can download the Digital Performer demo from the MOTU site. It's fully functional for 30 days and you can just set up a single stereo track session @ 48k, transfer the tapes and then export the WAV file. There are other demos out there, but just make sure they don't restrict saving files.

[bayswater]

I’ve never been able to get stable timing with a 828 Mk3 or 2048 Mk2 using ADAT or SP/DIF. I get dropouts with either. Using word clock has worked.

[OinkQuack]

Try using something other than Audacity - something that uses the ASIO driver. If you don't already own a DAW/audio recording software that uses ASIO, you can download the Digital Performer demo from the MOTU site. It's fully functional for 30 days and you can just set up a single stereo track session @ 48k, transfer the tapes and then export the WAV file. There are other demos out there, but just make sure they don't restrict saving files.

Thanks. I'll try that.

[OinkQuack]

I’ve never been able to get stable timing with a 828 Mk3 or 2048 Mk2 using ADAT or SP/DIF. I get dropouts with either. Using word clock has worked.

Yes, old technology, eh? Word clocks and magnetic tape. When you say that word clock worked, did you use some external word clock unit, or do you mean the clock generated by your MOTU gear?

[bayswater]

I’ve never been able to get stable timing with a 828 Mk3 or 2048 Mk2 using ADAT or SP/DIF. I get dropouts with either. Using word clock has worked.

Yes, old technology, eh? Word clocks and magnetic tape. When you say that word clock worked, did you use some external word clock unit, or do you mean the clock generated by your MOTU gear?

Just putting the BNC cable between the two interfaces and selecting one of them as the timing master. No external timing units. That has worked for me connecting two MOTU units, or connecting a MOTU interface to some old Tascam gear.

Using ADAT or SP/DIF for timing has always showed, at best, some drift in timing, resulting in dropouts every couple of minutes. The timing errors have been small enough to fix with a sample editor, but completely eliminated using Wordclock.

[CharlzS]

I think any discussion of using word clock along with Windows Audio may be futile.

[OinkQuack]

I’ve never been able to get stable timing with a 828 Mk3 or 2048 Mk2 using ADAT or SP/DIF. I get dropouts with either. Using word clock has worked.

Yes, old technology, eh? Word clocks and magnetic tape. When you say that word clock worked, did you use some external word clock unit, or do you mean the clock generated by your MOTU gear?

Just putting the BNC cable between the two interfaces and selecting one of them as the timing master. No external timing units. That has worked for me connecting two MOTU units, or connecting a MOTU interface to some old Tascam gear.

Using ADAT or SP/DIF for timing has always showed, at best, some drift in timing, resulting in dropouts every couple of minutes. The timing errors have been small enough to fix with a sample editor, but completely eliminated using Wordclock.

The Tascam DA-30 MkII has AES/EBU XLR digital inputs and outputs, but I believe it only improves on signal strength and over longer cables and would have to terminate with an RCA plug for the MOTU 4Pre. So, probably not worth it.

[OinkQuack]

Try using something other than Audacity - something that uses the ASIO driver. If you don't already own a DAW/audio recording software that uses ASIO, you can download the Digital Performer demo from the MOTU site. It's fully functional for 30 days and you can just set up a single stereo track session @ 48k, transfer the tapes and then export the WAV file. There are other demos out there, but just make sure they don't restrict saving files.

I downloaded the demo of Digital Performer 11.11 and it worked beautifully. There were some issues which I have yet to determine the cause of, but are most likely tapes that I recorded some on 44.1KHz and others on 48KHz. However, all-in-all a great result. Thanks for the advice. It seems that MOTU ASIO drivers, at least, were the key.

[CharlzS]

Glad it worked. DP is a great DAW and has finally found its legs in Windows. Something you may want to add to your arsenal.

[mikehalloran]

…There were some issues which I have yet to determine the cause of, but are most likely tapes that I recorded some on 44.1KHz and others on 48KHz. …

DP. like all other commercial DAWs, can convert nearly sample rate/bit depth format to whatever you want without changing pitch or other anomalies—even live from your DAT machine. With DP, this is set up in Preferences. In addition, it can convert most file types such as mp3 by importing or dropping the file onto a track.

I have no idea if Audacity can handle these routine tasks or not.

[OinkQuack]

…There were some issues which I have yet to determine the cause of, but are most likely tapes that I recorded some on 44.1KHz and others on 48KHz. …

DP. like all other commercial DAWs, can convert nearly sample rate/bit depth format to whatever you want without changing pitch or other anomalies—even live from your DAT machine. With DP, this is set up in Preferences. In addition, it can convert most file types such as mp3 by importing or dropping the file onto a track.

I have no idea if Audacity can handle these routine tasks or not.

For free open source software, Audacity is surprisingly versatile and professional. It covers all the sample rates/bit depths. However, the MOTU ASIO drivers were far more precisely compatible with the 4Pre than what Audacity was able to offer.

I've used Audacity for restoring old analogue tape recordings many times. It has an interesting noise reduction plug-in that allows one to sample a section of tape hiss and then use it as the pattern to strip the hiss from the entire recording. I expected it to have a negative impact on the high frequencies, but it's pretty good. However, sometimes the hiss is part of the vibe .

I re-recorded the DAT tapes with issues. There were not, as I suspected, different sample rates on the same tape; it was all 48kHz. So, I stopped the tape before the problematic track/s ejected the cassette, spooled and tightened the tape, re-inserted it and the recording was fine.

I think it's an issue with the Tascam DA-30 MkII, possibly the brakes. However, it seemed specific to certain cassettes. So, perhaps the mechanics of the cassettes were at fault.

Now, I only have one DAT left with some drop-out at certain points. I believe this is due to some physical creasing of the tape when it got eaten by the machine before I cleaned it. One tip I read is to fill and seal a glass jar with hot water, dry the jar thoroughly and then run it along the back of the tape, presumably to soften the tape and potentially smoothen the creases. I have all the contents apart from the last track. So, I'll have to locate that track, eject, spool out a metre or two and give this technique a try. Perhaps I'll try a sheet of paper between the jar and the tape.

[mikehalloran]

…

I've used Audacity for restoring old analogue tape recordings many times. It has an interesting noise reduction plug-in that allows one to sample a section of tape hiss and then use it as the pattern to strip the hiss from the entire recording. I expected it to have a negative impact on the high frequencies, but it's pretty good. However, sometimes the hiss is part of the vibe .

I've been using iZotope RX to do that for 15 years or more—I really don't remember.

RX Elements does all of that and much more. Part of the FX Bundle with Ozone/Neutron/Nectar Elements and currently on sale $20 if one knows where to shop.

https://www.pluginboutique.com/product/ ... ents-Suite

[CharlzS]

For free open source software, Audacity is surprisingly versatile and professional. It covers all the sample rates/bit depths. However, the MOTU ASIO drivers were far more precisely compatible with the 4Pre than what Audacity was able to offer.

If you're looking for some free stuff . . . since you own a MOTU audio interface, contact MOTU tech support and they possibly will give you a license for Performer Lite. Others have done this.

Some other very capable free options:
https://shop.presonus.com/Studio-One-5-Prime
https://www.tracktion.com/products/waveform-free

Any of those with Izotope RX (ala Mike) will work great (or just RX stanalone).

I'm not quite sure what's keeping the Audacity folks from developing an ASIO environment, but maybe someday. Also, if multitracking it can get quite confusing.

[James Steele]

I've been using iZotope RX to do that for 15 years or more—I really don't remember.

RX Elements does all of that and much more. Part of the FX Bundle with Ozone/Neutron/Nectar Elements and currently on sale $20 if one knows where to shop.

https://www.pluginboutique.com/product/ ... ents-Suite

Hey Mike... out of curiosity have you tried out Waves Clarity Vx plug? I don't have the "pro" version, but the standard version seems to work really well. I also have the Acon Digital Restoration Suite, but found Clarity Vx was much simpler. I've mostly used it to get rid of tape hiss when digitizing old recordings that I only had on cassette tape. Ugh.