DAT

Recording up to zero level on digital isn't a good idea, but it depends on the device what actually happens. For example, Sony MiniDisc recorders plainly have a limiter in them, because I've gone over max level on occasion and it's been OK. If your Tascam doesn't have this you will get horrendous distortion as soon as you go over. The best thing to do is to do some tests. However for general use I would advise staying 4 to 6 db below peak. (If it's 16-bit the noise level is -90dB so losing a few dB off that won't hurt. The BBC, for example, set peak level on their meters to -10dB on the digital input.)

If you want to copy it into Logic by far the best way is to do a direct digital connection. Current Macs don't come with a digital input, so you would need an interface. Older ones - going back several years - have an optical input (the 3.5mm line input doubles as a TOSlink input).

I have one of the older Tascam's as well, a DA-30, great unit, and I agree, recording analog out from a good Mixer is a sound I prefer than just keeping a bounced file in the digital domain. Not sure if I could say what it is that's different, stereo placement seems more open, the sound seems to breathe, all subjective I know.

I think the Tascam may have an extra DB headroom so as long as the 0db isn't flashing you will be ok. If you're going to send the recording back to Logic and do some mastering final compression/EQ...etc, then you will want to leave yourself a bit more headroom.

I agree that going back to Logic should be a digital transfer, two analog bounces may lose some of clarity.

What soundcard do you have? Were you speaking of the computers build in audio. If it's the bbuilt-in audio forget it, a computers built in audio is noisy and inaccurate. You will need a Compatible Interface with an s/pdif digital Input/Output, your Tascam has s/pdif IN/OUT correct?

I'd have to disagree with Roger... hitting a DA-30 at - 6dB is not taking advantage of it's (excellent) 16 bit converters, & your -2dB setting with (very) occasional overs is more likely to deliver more pleasing results. Of course, conventional wisdom is that digital overs are a "no-no", but in the case of DA-30's (& many other decent 16 bit converters), it's quite hard to hear any adverse effects, (unless you go crazy with the levels).

Bare in mind that metering will not display overs on playback, (so trust your ears), & it's always a good idea to use a limiter or compressor to tame unruly levels on outboard midi instruments when recording them in.

Having had to dig out some 20 year old masters recently, I concur that the DA-30 was indeed a fine machine, (& puts many modern 24 bit interfaces to shame).

If you can go over maximum level on digital without adverse effects then the device has a built-in limiter which is holding the level down in the analogue domain (as the Sony Minidisk recorders do). This is a good idea to prevent accidents, and fine if you don't mind a bit of compression. If you don't have this safety net, going over the limit causes the device to 'run out' of bits and do a hard clip on the waveform, producing a loud crackling distortion.

I usually allow about 3dB of headroom - and quite often having taken level get a higher peak at some point - I don't know what other organizations do but as I say the BBC regard peak level as being -10dB from maximum in digital; this doesn't necessarily translate to -10dB at the transmitter: I suspect that takes the transmitter to about full modulation. (They tend to have limiters in anyway - in the days of AM over-modulating would take the transmitter off the air, and with FM it would cause wider sidebands which would cause interference with other stations.)

Recording right up to the maximum produces very loud recordings compared with many others - of course that's what many people want. In the pop word heavy compression and peak limiting are often the norm anyway.

F~L~E~X~I~S wrote:

As far as I'm aware DA-30's don't have a built in limiter, but their converters do give a pleasing analogue 'style' saturation when pushed.

Which is interesting. If there is no analogue limiter, then suppose you put in a signal at maximum level (and assuming we're talking 16-bit) then this registers as 1 16 times (I don't feel like typing that out). Anything louder still registers as 1 16 times because there is no way of describing any higher level; so the result is hard clipping. How the DA-30 gets round that I don't know, but I would have thought there must be something going on in the analogue domain to handle it.

Slightly off-topic, valve (tube) amplifiers do a 'soft' overload - the distortion builds as you push it too far as the waveform deforms. However transistor amplifiers hard clip. When they first came out people kept complaining that they sounded worse than valves because of the hard clipping. I would have thought the answer to that was not to overdrive your amplifier 🙂. People still like valve amps because of the warm fat cuddly sound some of them produce (it's called microphony, from the speakers vibrating the valves). Plus a bit of 2nd harmonic distortion. Many people don't like accurate reproduction - they call it 'clinical' (sigh).

Bv2017 wrote:

My Tascam DA -30 has digital I/O COAXAL and digital I/O port( AES/EBU) which of these should I connect the cable once I have the interface? No, I do not use the built it mac soundcard, although I tried it once as I heard musicians that use it and in fact, I like it too, but for now, I am sticking to my Steinberg USB UR series.

Since I want to retain the exact clarity, I will avoid the analogue inputs of my USB soundcard as you hinted out. Finally, I am wondering if Logic will be synched with my Tascam once I have the above digital connection and if they will both start simultaneously.

the Coaxial connection the DA-30 is the s/pdif digital connection you will use. You would use the coaxial output only of the Tascam to whatever you're using for a digital recording. The Tascam will be the master clock, and the recording device will either automatically sync or will need to be manually set to sync to the Tascam's digital clock. No, Logic will not start automatically... that's irrelevant, once the digital clocks are locked you can start Logic recording and press play on the Tascam at anytime.

All that said.. I would try an analog recording from the Tascam to the Steinberg UR, it may be satisfactory. Digital sync is not used on an analog transfer.

p.s. The Digital clock is embedded in the sample rate, so 44.1kHz 48kHz...etc is the digital clock. All digital clocks are not equal, one unit my be 44.10046 another 44.100089, these are what must be locked. The transmitting device is the master, the recording device slaves to the the transmitting device's clock, otherwise you can get audio artifacts.

Most certainly a computer's analogue audio input should be avoided: some older Macs have an analogue jack which also handles optical digital, and I'm cross with Apple for removing it. I have a 2008 iMac which has this and it works perfectly; for later Macs you are forced to buy and interface of the sort you describe and these have become rather expensive. With my 2014 iMac I use an Edirol UA-3FX which converts analogue or digital signals to USB but these have been off the market for some years and everything now seems to cost several times what that cost.

I agree Roger, & should add that my advice is specific to the DA-30, rather than modern 24 bit interfaces (which have an increased dynamic range & therefore don't require such high input levels). As an englishman... I do also take the BBC's advice as gospel (when not recording to DAT)! 😉

As far as I'm aware DA-30's don't have a built in limiter, but their converters do give a pleasing analogue 'style' saturation when pushed.

I think the DA-30 had 18-bit converters and it may be the analog input stage that's giving it the (sound)?

Specs.

(64x oversampling Delta-Sigma A/D, 8x oversampling 18 bit D/A)

All I know is at the time, they were some of the best converters on the market.

Most interfaces use coaxial, or optical TOSlink. Either is fine: 10 metres is about the longest you can safely use. AES is a more professional connection, using XLR connectors, which can run long distances but I doubt many semi-professional interfaces use it.

If your Mac is an older one and has the 3.5mm input jack which doubles as a mini-TOSlink (optical) this is fine (it doesn't suffer from the problems which the analogue input does): of course as your Tascam has only a coax output you will need to convert - you can probably still get small optical-coax and coax-optical converter boxes relatively cheaply.

I don't know about Logic, I shall have to leave that to someone familiar with it. It may, like the Sony Minidiscs, have the start recording as soon as there is modulation facility - but in any case when making digital recording there's no problem about deleting the silence at the start (it's not like cutting off and having to throw away tape!).

The issue is that some Macs have no digital input (that applies to the recent ones), some have a separate input jack which doubles as an optical input, and some have a single jack which can be switched in System Preferences to accept an input which may be analogue or analogue and digital (I think that's probably only some laptops).

If you go to Applications/Utilities/System Information and quote the Model Identifier (e.g. imac14,2) then it should be possible to determine exactly what inputs you have.

If your Mac is a recent one you are going to have to invest in an interface. Actually the best place to ask about this may still be (as it was some time back) in the Garageband for Mac forum as there are people there who have direct experience. (The interface I use has been out of production of years, so that's no help to you.)