I was assuming once the signal was converted at the V3 to a line level signal, that whatever db signal is leaving the V3 should be the same as the db level of the signal that the 744 sees coming from the V3. Am I mistaken? I could adjust the input level in the menu of the 744, but, shouldn't running the V3 properly guarantee a good, non-clipped signal coming into the 744?
Yes to the first question, not necessarily to the second. Different recorders have different definitions of "line level". Some recorders (typically consumer) define line level as -10 dBu. Other recorders (typically pro) define line level as +4 dBu. And some gear doesn't follow either of these standards at all. What do these "line level" references actually mean? These "line level" references basically define the strength of signal the analog input may receive without overloading, and not necessarily the signal strength required to achieve proper dBFS levels at the ADC.
Moke/Brian, when you run the V3 so that the first amber light comes on (9), how high do the lights on the 7xx go (going into line in 3&4), one past the -12? I am curious how high you let the led's go on the 744.
I don't have a 7xx, so I can't answer your question specifically. But in general, if you're running at 24-bit, set levels fairly conservatively. On my Oade-modded Edirol R-4, I typically set them to peak somewhere around -12 dBFS. This provides headroom for unexpected spikes, yet still takes advantage of the extra resolution 24-bit provides. So, if you're running V3 analog out > 744, I'd say start by running your levels to peak around -12 dBFS using the level meters on the 744 (not the V3).
As I suggested before, you may achieve levels of -12 dBFS on the 744 by using various amounts of gain on the V3 and/or 744. For the sake of discussion, let's say that at a given concert your mic signal requires a total of +35 dBu of gain in order to achieve levels of -12 dBFS on the 744. We can deliver the +35 dBu of gain in multiple ways, using gain from the V3 and/or the 744. The following table lists examples of some (but not all) different options:
V3 | 744
=============
+35 | + 0
+25 | +10
+15 | +20
+10 | +25
+40 | - 5In the first row, we're delivering all +35 dBU from the V3. The next three rows are examples of providing some gain from the V3 and some from the 744. And the last row illustrates how we could send too much gain with the V3, but trim it back on the 744. In all examples, the total gain delivered to the 744's ADC is +35 dBu, which means in all cases our levels are peaking at -12 dBFS (based on our initial assumption that + 35 dBu will achieve levels of -12 dBFS on the 744).
The amount of gain required to achieve peaks of -12 dBFS (or whatever peak threshold at which you choose to run) will change depending on the volume of the source you're recording, but the concepts above will apply in all cases. It's entirely up to you how much gain to apply on each device. Try different options. Over time, you'll identify which option(s) sounds best to your ears.
I see in your signature you also may run the V3 digi-out to an MT2496 simultaneously with V3 analog-out to the 744. In this case, the V3's doing double-duty: delivering an analog signal to the 744 as well as it's internal ADC (and subsequently a digital signal to the MT2496). In this scenario, you want to ensure your levels are set properly for both levels at both the V3 and 744's ADC. First set your levels on the V3 using the V3 meters (to peak at, say, -12 dBFS). Then, make whatever adjustments you need to on the 744 to achieve the levels you wish (again, say, -12 dBFS) using the 744 meters. In this scenario, you won't have the flexibility of running different gain options like I listed in the table above because there will be only one gain level at which you're sending the desired levels to the V3's ADC. This will provide a fixed gain value to the 744 and you'll need to adjust levels on the 744 to achieve the desired levels on its meters.
Topic: V3->744 Level Issue (Read 2062 times)