Transferring/mixing 4 track to digital

[Jojofrekote]

Hi everybody, glad to be here. Thanks for reading and maybe helping me out a little bit. Let me phrase my questions first by describing my setup and goals, and please don't chide me too much about the equipment I'm using or general ignorance, because I'm here to hopefully learn from others' experience and do the best I can with what I have.

For the last few years I have been teaching myself to record with a Yamaha 4-track (MTX4?) with a built in mixer. A year or two back I got a 2 channel preamp and also a compressor, cheap Guitar Center stuff, that I could use for recording. I also got a second identical 4-track that is broken only in that it doesn't record at all, so I was using it for playback and doing stereo mixdowns on the good 4-track and using the new open tracks for dubs like vocals. I picked up some weird home-stereo spring loaded "reverbamp" at goodwill and used it in a little of the mixing.

Lately I decided the only way to finish up the tapes is on the computer, so I got a (cheap) USB digital converter with 8 XLR and 8 1/4 inputs, to record the 4 tracks from the tapes, and simultaneous FX feeds sent from the tape to the reverb or compressor into digital, all recorded separately for final individual noise reduction and panning. I'm using the software Reaper which suits my needs alright, i.e. it's free.

So here we go:

1. I don't know very much about recording digitally but understand that (ha) unharmonic digital distortion doesn't sound good. How hot is too hot on the computer? I've got good signals coming in without turning up the amps on the converter but use them a little to max it out. At a max of 0.0 decibels is where I'm no longer hearing any distortion but I was wondering if there's some kind of rule behind this.

2. I've got all the equipment plugged into one power strip. Is this okay? There was some weird noise in the channels and noticed that when I unplugged my computer (a laptop) that it went away. I know that there are power conditioners to aid in grounding or something... feel like a rube not knowing about electricity but would assume if it was all plugged in together, it would ground properly. And before you ask I know what happens when we assume.

3. Uh, cable stuff. Maybe this doesn't matter. I am using rca-XLR adapter cables for going from the tape machine to the amp&compressor, and normal XLR cables from that rack stuff to the computer. rca-1/4 cables go from the tape to the second 4track which can split the signal, and that goes rca-XLR to the computer and rca-rca to the reverbamp, and rca-1/4 from reverbamp to the computer. My ignorance comes through again here, as I've read about balanced signals but really haven't understood it. What kind of electrical or audio problems might I experience because of all this conversion within the different analog stuff, once it's recording on the computer?


I really appreciate any constructive comments you folks may have to make; back in a bit to see if anyone's posted. Thanks!!

[ashcat_lt]

1. I don't know very much about recording digitally but understand that (ha) unharmonic digital distortion doesn't sound good. How hot is too hot on the computer? I've got good signals coming in without turning up the amps on the converter but use them a little to max it out. At a max of 0.0 decibels is where I'm no longer hearing any distortion but I was wondering if there's some kind of rule behind this.

There's no benefit to recording with peaks at 0. Among other things, you're likely adding unnecessary gain on the way into the computer. You're going to have to turn these tracks back down ITB in order to keep from distorting your mix bus. Especially if you're recording at 24 bit, you'll get plenty of resolution even with significantly lower levels.

Most folks seem to shoot for averages around -18dbfs, with peaks around -6 or a little more. Set up your system so that when the meters on the analog machine reads 0dbVU, the computer sees about -18dbfs and you should be in optimal territory.

2. I've got all the equipment plugged into one power strip. Is this okay? There was some weird noise in the channels and noticed that when I unplugged my computer (a laptop) that it went away. I know that there are power conditioners to aid in grounding or something... feel like a rube not knowing about electricity but would assume if it was all plugged in together, it would ground properly. And before you ask I know what happens when we assume.

Plugging everything into one power strip is usually a good way to minimize ground loop issues, though it doesn't always work. Unfortunately it also means that power supply noise from one object can end up contaminating others. The type of PS used for laptops is pretty notoriously noisy. I think you've already found your cheapest solution for this. Run the laptop from battery power while dumping tracks.

3. Uh, cable stuff. Maybe this doesn't matter. I am using rca-XLR adapter cables for going from the tape machine to the amp&compressor, and normal XLR cables from that rack stuff to the computer. rca-1/4 cables go from the tape to the second 4track which can split the signal, and that goes rca-XLR to the computer and rca-rca to the reverbamp, and rca-1/4 from reverbamp to the computer. My ignorance comes through again here, as I've read about balanced signals but really haven't understood it. What kind of electrical or audio problems might I experience because of all this conversion within the different analog stuff, once it's recording on the computer?

I got a little lost in there, but I think it'll work okay. You should try to run true balanced connections where you can, but the tape machine doesn't have balanced outputs, so that kind of limits your options. I worry about the RCA>XLR thing only because it sounds like you're running the (line level) tape outs into mic inputs. These might present an impedance a little lower than what the tape machine "expects" and also introduces an unnecessary gain stage.

I guess some of these connections may not be optimal. Unless there's a noticeable degredation of the sound, though, you're fine.

[MoreSpaceEcho]

i think peaking at -6 is still too hot, by about 6db, but ymmv. definitely don't track any hotter than that. otherwise i agree with what ashcat it wrote.

laptop power supplies are the work of the devil.

[dgrieser]

Reaper isn't free. You have a 30 day trial period. True, it never gets disabled so it's easy to never pay for it, but it's only $60 for a non commercial license.

There are some free/open source DAWs like Audacity if you need free.