analog to digital problem

[Dick Ward]

I’m a new user looking for some help. I have a Teac 80-8, 8-track recorder, using ½ inch tape.

I am currently trying to record an acoustic guitar album. This is my process:
1. Record a drum machine click track with vocal count off on track 8
2. Record the music tracks on the 80-8, on tracks 1-7, using the click track.
3. Dump the tracks to CD, one at a time, with the click track and count off at the front of each music track
4. Take the CD to a commercial digital recording studio.
5. Assemble the tracks at the digital studio, then mix and master.
6. At the studio we visually line up the tracks in Pro Tools using the click track and count off at the beginning of each track.

Here is the problem: Even though the tracks are exactly lined up at the click track and count off, the second track gradually slips back a few milliseconds so that by the end of the cut we have a slap back echo. Same thing happens with other tracks so that none line up exactly; they all come in a few milliseconds late by the end of the song.

This is even true where I record one guitar part to tracks 1&2 at the same time, track 1 miked and track 2 direct from the pickup.

The machine has less than 20 hours use since a complete rebuild about 7 years ago. It has a new rubber pinch roller. The tape is Quantegy 456, fresh from the sealed plastic baggie, though it was purchased about 5 years ago and stored in a humidity-controlled room. Very little of the tape coating comes off on heads and tape path hardware during use, i.e. hardly any residue comes off on the Q-tip when I clean after use.

When I play the tracks back on the 80-8, they are perfectly lined up. I dump them to a Tascam CD-RW700, in good repair, by playing back the first track, rewinding, and doing the same with the rest of the music tracks.

Any ideas? Thanks,
Dick Ward

 

[Chilljam]

Yes this happens with all tape machines, because you are playing back each track separately, that would mean that the machine would have to playback at EXACTLY the same speed each time and this is impossible due to the mechanical nature of the machine.

There is nothing wrong with your machine in that sense, all machines will have this problem (some a lot worse than others).

You have to dump all 8 tracks simultaneously (using an 8 channel A-D converter) OR you can record off the repro head straight to the CD player AS YOU ARE TRACKING. Since your CD player is only two channel, this means that you can only record two tracks at a time using this method.

I have been using that method of sending the signal to the DAW straight from the repro head whilst recording to record whole albums and it works and all your tracks stay lined up.

 

[miroslav]

...OR you can record off the repro head straight to the CD player AS YOU ARE TRACKING.

When you do this...where are you getting your scratch/cue tracks from...the tape or the DAW?

If you go back and do multiple, individual tracks from a tape cue...you would still have the drift problem....no?

 

[SteveM]

You're other option is to use a midi stripe on one track of the 80 8. But you'll need a cd burner that can slave. And of course a midi synchman or something like it. Even with that though sometimes there is a possibility of "wow" or "flutter" while it's slaving. Depends how tight the playback is on the 80-8. With most "newer" decks it's fine. I know with my 3340 it works well but my Ampex, midi stripe doesn't work well. Unfortunately!

 

[Dick Ward]

Ok, thanks, I get it now. I see that A-D converters are very expensive. So to option 2. The 80-8 has 3 heads: input, norm, and monitor and you can output from all three. The norm is the sync head, and the monitor is the repro head. You can only access one output at a time. I don't think I can record various tracks, guitar, vocal, bass, etc. while outputing from the monitor (repro) head. I have to be set to the norm (sync) head to be able to record along with an existing track. Any ideas for a workaround without going to the A-D converter?

Many thanks,

 

[miroslav]

I don't think I can record various tracks, guitar, vocal, bass, etc. while outputing from the monitor (repro) head. I have to be set to the norm (sync) head to be able to record along with an existing track. Any ideas for a workaround without going to the A-D converter?

There is no workaround without a proper sync setup if you are going to record track-by-track and then transfer them track-by-track. Doing it that way...the only option is editing in the DAW...adjusting whatever is drifting out of sync.
It's actually not that hard, though it can be time consuming as your track count increases.

The person at the digital end...don't they have a multi-channel A/D setup and/or a tape deck? Send the tape if they have a deck, or if not and if they are close by, bring your deck over to their place and make the transfer.

 

[Chilljam]

When you do this...where are you getting your scratch/cue tracks from...the tape or the DAW?

If you go back and do multiple, individual tracks from a tape cue...you would still have the drift problem....no?

Yep that's correct.

Actually, come to think of it, with the 80-8 and CD-RW700 setup... this method wouldn't be practical because I don't think you can playback recorded tracks on the CD-RW700 whilst recording new ones. Worked great for me using a Tascam 32 and a Roland VS-1680.

I don't think I can record various tracks, guitar, vocal, bass, etc. while outputing from the monitor (repro) head. I have to be set to the norm (sync) head to be able to record along with an existing track. Any ideas for a workaround without going to the A-D converter?

I think you are misunderstanding the process... Yes you have to be in sync mode to record a long side a track on the tape machine, but you don't want to record a long side a track on the tape machine, you want to record a long side a track on the DAW as that track will playback at exactly the same speed each time and since you are recording in 'realtime' from the repro head then you are in perfect sync with the digital track (then you just minus the delay between the sync and repro heads) and it's all synced up nicely.

But like I said, if you are only using the CD writer then it's not a practical method. Like miroslav said, record everything on the 80-8 then give your tape to the digital studio and they will be able to transfer the individual tracks to digital (almost all studios will have an audio interface for the job).

Otherwise you can either buy your own 8 channel audio interface or you can mix in analog and master to digital (using the CDRW).

 

[Dick Ward]

I sure appreciate the help here, but I think I am still stupid about this. Say I get an 8 channel A-D interface, I am still left with trying to move 8 tracks analog to the CD-RW700, a two track digital recorder with two inputs. So how can I move 8 tracks all at once and get 8 individual cuts on a CD to take to the studio. Again I apologize for being thick-headed on this.

 

[jpmorris]

You don't really want to use that recorder at all for this - it's not designed for what you're trying to do here. Putting a multitrack onto an audio CD is going to be extremely messy whatever you do and it's almost certainly not what the engineer is expecting to receive.

Your best is to use a computer with an 8-channel interface. Use software on it that can record all 8 tracks at once and export them as 8 parallel WAV files. Burn your WAV files onto a CD-ROM or put them on a thumb drive, and take those to the studio. The engineer could then rip the CD (which will probably introduce jitter), import them into a new project there and you can do whatever it was you need.

The only alternative I can see - which is the last line of Chilljam's post - is to mix down your 8 tracks to stereo using a small mixing desk, and record that to CD using your existing recorder. You can import the stereo pair to the studio's own system and use it as a backing for the rest of the song, but doing that will of course prevent you from being able to alter the mix of those 8 tracks later.

 

[miroslav]

^^^^^^^ ditto ^^^^^^^

 

[jpmorris]

One important point I didn't make clear enough is that you really want to put your 8 WAV files onto the CD as files, not burn them as audio tracks.
As files, the engineer can just read them off the CD and import into whatever DAW system he's using. They should be exactly the same as what you wrote to the disk.

If they are written as audio tracks, he/she will have to rip the CD to get the tracks off and this will introduce jitter into the process which you do not want to have.

 

[SteveM]

I think you are misunderstanding the process... Yes you have to be in sync mode to record a long side a track on the tape machine, but you don't want to record a long side a track on the tape machine, you want to record a long side a track on the DAW as that track will playback at exactly the same speed each time and since you are recording in 'realtime' from the repro head then you are in perfect sync with the digital track (then you just minus the delay between the sync and repro heads) and it's all synced up nicely.

I understand you're monitoring the previously recorded tracks off the DAW but are you hearing the output of the track you're recording in the mix while you're recording it?

 

[Chilljam]

I understand you're monitoring the previously recorded tracks off the DAW but are you hearing the output of the track you're recording in the mix while you're recording it?

Yep, if you feed the DAW output into your outboard mixer then plug in your microphone that you are recording into the mixer as well then you can hear them both 'in time'. Then you just send the microphone that you are recording through the aux buss into the reel to reel recorder, set it in 'repro' with the output connected to the DAW, then hit record on the DAW and record on the tape machine.

 

[SteveM]

Yep, if you feed the DAW output into your outboard mixer then plug in your microphone that you are recording into the mixer as well then you can hear them both 'in time'. Then you just send the microphone that you are recording through the aux buss into the reel to reel recorder, set it in 'repro' with the output connected to the DAW, then hit record on the DAW and record on the tape machine.

But you can't do any punch ins?

 

[Chilljam]

But you can't do any punch ins?

Yes you can, the method is exactly the same as recording straight to the DAW (through an analog mixer) only you are 'passing' audio through the tape and hence the 100ms or so delay.

 

[SteveM]

Yes you can, the method is exactly the same as recording straight to the DAW (through an analog mixer) only you are 'passing' audio through the tape and hence the 100ms or so delay.

OK cool. Thanks

 

[miroslav]

Yes you can, the method is exactly the same as recording straight to the DAW (through an analog mixer) only you are 'passing' audio through the tape and hence the 100ms or so delay.

Right...and the added benefit is that the "delay" will be accurate from start to finish since it comes right off the playback head almost as fast as it is recorded to the tape...so none of that tape "drift" that you see with longer songs.
So you just slide the new track into position, and everything lines up.

Drop a couple of clicks in the same spot at the start of all tracks, and the lining up is a real easy...just line up the clicks.

 

[fstrat76]

So you just slide the new track into position, and everything lines up.

I usually will do 7 tracks at time with a click track then move them over to the DAW and line it all up.

But I'm trying to wrap my head around your punch in process using the repro head method:

Let's say you lay down a track by recording into the DAW off the repro head. Easy enough. But now you need to punch in a part, or start from a certain point. You need to line up the first recording of the track with the rest of the song (offset by the repro head, say 100ms). Then you fire everything up again, set the DAW to record/punch again, set the tape to record, set to play a few bars before the punch point, and punch in your new part.

So then you are saying, for every successful punch, you will need to shift that punched in part each time, correct?

Of course, its best when you can play a part through, but on experimental material, there could be a lot of punches.

 

[SteveM]

I usually will do 7 tracks at time with a click track then move them over to the DAW and line it all up.

But I'm trying to wrap my head around your punch in process using the repro head method:

Let's say you lay down a track by recording into the DAW off the repro head. Easy enough. But now you need to punch in a part, or start from a certain point. You need to line up the first recording of the track with the rest of the song (offset by the repro head, say 100ms). Then you fire everything up again, set the DAW to record/punch again, set the tape to record, set to play a few bars before the punch point, and punch in your new part.

So then you are saying, for every successful punch, you will need to shift that punched in part each time, correct?

Of course, its best when you can play a part through, but on experimental material, there could be a lot of punches.

I was wondering the same thing. But I was thinking you would just leave it where it was, punch in and punch out and THEN line it up. Or no punch out, you'd have to continue til the end.

 

[miroslav]

I don't bother with "punch-ins" as the way one would do a tradition tape punch-in.

I simply do takes...as in whole tracks. If I want to record a new section for say, Chorus 1...I'll still record a new take from the beginning and then play only when the Chorus 1 section comes up (the punch-in).

That way...lining up the tracks still takes place at the head..at the start of each track...instead of having bits-n-pieces of tracks.
It's a DAW, and most have a rather huge allowed track count...so it's no big deal to use up a whole track just to record a "punch-in" for Chorus 1.
Besides, once it's recorded, you can easily cut away what you don't want/need, and combine where applicable, if it's necessary to reduce track count or used up HD space...etc.