low input volume

[mokele]

I am looking to transfer a bunch of DATs to hard drive, then cut them into pieces per song. Later, I'll "improve" them, but for now I just want to move them into a more permanent, manipulable and easily backed-up medium.

I find that the input volume is really low (-24db) and there don't seem to be any controls for fixing that, either in my DAT player (Tascam DA-30 mkII) or in Audacity 2.0 (on a 2010 Mac Mini with tons o' RAM etc.).

Any pointers would be appreciated!

Thanks,

Jim

[steve]

How are you "transferring" the audio from the DAT to the computer?

If you are using digital transfer then there may well be no level control, but you can apply the Amplify effect (Effect menu) once you have the audio in Audacity.

[kozikowski]

Are you using the S/PDIF connection? DAT machines speak SDI -- Serial Digital Interface. They are designed to plug right in next to digital television station video equipment, Digital BetaCAM, DVCam etc. The standard is similar, but not identical to Sony/Philips Digital Interface.

The "VU Zero" point in US TV is -20dB and as a very general rule, you never touch the volume controls, although the larger tape machine have "scaling" controls that can change the volume of the work in or out. I'm not shocked that your machine doesn't have them. In commercial use, they're not needed.

Again in the US, shows enjoy 20dB Headroom before overload and given the limits of 16-bit audio, 76dB Noise Floor.

So that's what you have. If your Mac Mini is anything like mine, it has S/PDIF connections and you should be able to get adapter cables. As far as sound levels are concerned, what you have is perfectly normal. As above, you can apply Effect > Amplify to put the sound wherever you want. Consumer DV sound Zero VU is -12, not -20 and if you go much above that, you run the real risk of overload and clipping the show, although if you're editing in Audacity internal 32-float format, you can recover -- if you catch it. A simple 8dB boost in Amplify will convert from SDI to DV sound levels. Other numbers up to you.

Koz

[mokele]

Whoops! I left out an important piece. I'm using an ARTcessories USB Phono Plus as an interface. After these DATs, I have some records to digitize.

Am I better off looking for a spdif cable for the DATs? The original material was very much analog- everything from cassettes to 15 ips reel; it's pretty much my creative output from the 70's and 80's. I transferred it to DAT in the 90''s.

Thank you!

[kozikowski]

I would probably try to get the digital pathway to work for the DATs. The instant you go "down" to analog, the overload and noise points become those of the analog interface and I guarantee that they're going to be worse than 20dB overload and 76 noise floor -- possibly quite a bit worse. If you combine that conversion damage with the original analog work's characteristics, you could be reducing your crisp digital recordings to trash.

Possibly not, but you have a known, good, working pathway available to you.

Here's a reading from my System Profile:

Koz

[mokele]

Okay, it appears that I'll need to go then from RCA-sized coaxial on the DAT to mini-TOSLINK on the Mac. I looked on Amazon for a single cable to do such a thing; no luck, it seems. In fact, it appears that I need a Digital Fiber Optical (Toslink) to Digital Coaxial (S/PDIF) Converter, with cables on either end (M to M coax, and toslink to mini-toslink).

Does this sound right, and is there anything to watch out for, in selecting the parts?

I expect that I will be converting the dozen or so DATs I have, and then mothballing or selling the DAT, so road-worthiness is probably not a factor.

Thanks, again.

[kozikowski]

Does this sound right, and is there anything to watch out for, in selecting the parts?

Not in selecting the parts, no. I've only ever used the SDI Broadcast versions of this stuff, and I know that the interchange between SDI and S/PDIF - TOSLink isn't perfect. I'd be googling to find someone else who's tried this. I think one of the other engineers knows the technical differences. I can ask.

Yes, you're right. The Mac connection is optical digital.

Koz