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Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: markrsmith on July 03, 2013, 06:12:18 PM
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Where would I set my input levels on my ad2k+ ( 14 - 24) for a V2?
The V2 outputs a maximum of +27 dB (balanced) and +21 dBu (unbalanced).
The ad2k+ says to set the input level 3 - 6 dB before the mic preamp clips.
Seems to me I would set the ad2k+ at the 22 or 24 dBu level.
I get confused between dBu and dB.
Again thanx for the advice.
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yeah, you're in the ballpark. If you're connecting the two with unbalanced cables (why, I don't know, but I guess you could), then that would make a difference, but otherwise somewhere in the 20-24 range
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+27 dB (or dBv) is ~+29dBu, so you should be able to run the AD2k+ at +24dBu w/o worries.
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Thanx Guys!
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+27 dB (or dBv) is ~+29dBu, so you should be able to run the AD2k+ at +24dBu w/o worries.
this is how I run the combo.
turn that dial all the way over to the left...
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OK, so taking this one step further, once determining the optimal point, is there any disadvantage to running the ad2k+ below that as long as you aren't distorting.
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I am pretty sure that the two devices are calibrated closest this way. That is to say that what reads as peak is on the v2 is a peak on the ad2k+. For instance, when red lights are solid on the v2, I get over on the ad2k at this setting. When the dial was turned down, I would not get overs on the ad2k+
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you want +24 (least sensitive)
if it had +27 that would be 'matched', but it doesnt, so +24 is as good as it gets
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you want +24 (least sensitive)
if it had +27 that would be 'matched', but it doesnt, so +24 is as good as it gets
Based on what I recall, even if the AD2K did have a +27 sensitivity setting, it would be better to have it set one or two dB's below that. With the the AD2K set to +24, you'll get digital clipping at +24 dB, and because you know that the V2 won't overload until +27, as long as you're not getting any digital clipping, you will also know that you're not overloading the pre-amp.
Basically, you always want the A/D converter calibrated such that it clips digitally before your upstream pre-amp overloads. otherwise, if the pre-amp can overload before the A/D clips, then you could get a crappy recording (because the pre-amp overloads) and not know it just from watching levels.
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you want +24 (least sensitive)
if it had +27 that would be 'matched', but it doesnt, so +24 is as good as it gets
Based on what I recall, even if the AD2K did have a +27 sensitivity setting, it would be better to have it set one or two dB's below that. With the the AD2K set to +24, you'll get digital clipping at +24 dB, and because you know that the V2 won't overload until +27, as long as you're not getting any digital clipping, you will also know that you're not overloading the pre-amp.
Remember that you need to convert dBv to dBU.
+27 dB (or dBv) is ~+29dBu, so you should be able to run the AD2k+ at +24dBu w/o worries.
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I realize that the V2 manual (http://www.gracedesign.com/support/v2_manual_a.pdf) lists the max balanced output as +27 dB, and the max unbalanced output as +21 dBu. However, I think that's a typo, and I think the max balanced output on the V2 is actually +27 dBu. I think this is the case because balanced outputs, coming from the same amplifier circuit, are 6 dB higher than unbalanced outputs. +21dBu + 6dB = +27dBu. (this 6dB difference between the balanced and unbalanced outputs is also true with the V3, except that there's no typo in the V3 manual... +25dBu vs +19dBu for the V3).
in any case, regardless of whether or not the max V2 output is +27 dBu or ~+29 dBu, with the AD2K on minimum sensitivity (set to clip at +24dBu input), the AD2K will digitally clip before the pre-amp overloads, so as long as your levels look good, you'll be good to go.
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Ah, good catch. That could be a typo.
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Typos aside, I have found what Jason said to be absolutely true...