Topic: Ran V3>722 line in to the 722 last night and

[nedstruzz]

Although the V3 never hit zero and the meters on the 722 never hit zero the "over"  lights on the 722 flashed on and off. 

Now can someone please explain to me how the V3 never hits zero and the 722 never hits zero but the over lights on the 722 came on?   Any thoughts?

[fozzy]

over lights as in the ones in the top left area of the front panel.  I think they come on @ -3db

[nedstruzz]

Yes top left.  They can actually be set wherever you would like to see them come on.  I have mine set to 0dbfs which is the same as the V3.

[JasonR]

It may seem a bit counterintuitive, but the pair of LEDs at the top left (second row) are "input peak" and are not user adjustable.  They illuminate at -3dBFS.  When you set the "Meter: Peak Threshold" to 0dB, you're actually forcing the far right set of LEDs on the segmented meter to be 0dB.  That far right set of LEDs on the 722/744t can be set at something less than 0dB (0-20 I believe) though logically I wouldn't imagine most of us would use anything but 0, -1 or -2.

- Jason

[wolffman]

i know this doesn't have to do with the V3 and 722, but my "over" lights always flash on my sbm-1 without going "over" on the DA-P1.  Don't know if there is a similar scenerio with this setup??  sorry i can't help otherwise...

[nickgregory]

It may seem a bit counterintuitive, but the pair of LEDs at the top left (second row) are "input peak" and are not user adjustable. They illuminate at -3dBFS. When you set the "Meter: Peak Threshold" to 0dB, you're actually forcing the far right set of LEDs on the segmented meter to be 0dB. That far right set of LEDs on the 722/744t can be set at something less than 0dB (0-20 I believe) though logically I wouldn't imagine most of us would use anything but 0, -1 or -2.

- Jason



Jason is right the lights on the left side of the unit are not user assignable and are stuck at -3 db

[nedstruzz]

OK this makes more sense, I only wish they had told me this when I spoke with SD this afternoon???  Anyway, say I set the segmented meters at right to peak at 0dbfs then I change them to peak at -6dbfs what visual difference would I be seeing?

[Lil Kim Jong-Il]

Ned, how did you recording come out?  Have you had a chance to compare the two configurations?

[bkirby]

I have had a similar problem while running the V3 into the Masterlink at 24/96. The V3 peak lights come on, and the Mastrlink is at about -3db. To get the Masterlink to 0db, the V3 peaks continuously! I have yet to hear any distortion when the V3 peaks...

[marc0789]

I used to hit tons of reds on the v3, never an audible clip or even mild distortion. I think they must be off a bit.

[dmonterisi]

wouldn't this be because the v3 is probably built with some amount of headroom built in so that you wouldn't get overs so easily?  and if that was the case, then the signal sent out via the analog outs would similarly be just below 0 dbfs.

and what is the correllation between the analog db and the digital dbfs?  am i right that one is the analog unit of measurement and the other is the digital or is there something else?

[plucks]

a lot of time the V3 shows as "over" but that could have to do with where the over point is on the dB scale built into the V3.  And often that could be different from where "over" is on the next item in the chain...ad2k/mme/722. 

And either way, the V3 has a ton of headroom on it.  You can pretty much slam it and it shouldnt audibly clip

[MattD]

and what is the correllation between the analog db and the digital dbfs? am i right that one is the analog unit of measurement and the other is the digital or is there something else?

Yeah, that's pretty much it. I was going to write out an explanation, but this is more concise: http://www.jimprice.com/prosound/db.htm

[wboswell]

a lot of time the V3 shows as "over" but that could have to do with where the over point is on the dB scale built into the V3.  And often that could be different from where "over" is on the next item in the chain...ad2k/mme/722. 

And either way, the V3 has a ton of headroom on it.  You can pretty much slam it and it shouldnt audibly clip

while you may not hear the audible clip on your playback device, clips are visible when viewed in Wavelab, Sound Forge, or CD Wave that there is clipping.

Something to consider is that the a/d in the V3 is calibrated to clip before the analog section.  When 0dBFS is reached on the (digital) meter, the analog section outputs 25dBu.  This is why you have to run the pad going line in on the 722 while being fed an analog signal out of the V3 (while sending the digital signal to a 16 bit source). 

[marc0789]

a lot of time the V3 shows as "over" but that could have to do with where the over point is on the dB scale built into the V3.  And often that could be different from where "over" is on the next item in the chain...ad2k/mme/722. 

And either way, the V3 has a ton of headroom on it.  You can pretty much slam it and it shouldnt audibly clip

while you may not hear the audible clip on your playback device, clips are visible when viewed in Wavelab, Sound Forge, or CD Wave that there is clipping.

Something to consider is that the a/d in the V3 is calibrated to clip before the analog section.  When 0dBFS is reached on the (digital) meter, the analog section outputs 25dBu.  This is why you have to run the pad going line in on the 722 while being fed an analog signal out of the V3 (while sending the digital signal to a 16 bit source). 

wha Is there an onboard pad on the 722?

[wboswell]

wha Is there an onboard pad on the 722?

Sorry, wrong word...  I should have said Trim.  You've got to Trim the gain knobs to attenuate the signal by somewhere around -7dBFS..  or atleast that's been my experience.

[marc0789]

wha Is there an onboard pad on the 722?

Sorry, wrong word...  I should have said Trim.  You've got to Trim the gain knobs to attenuate the signal by somewhere around -7dBFS..  or atleast that's been my experience.

ah, makes sense. easy to confuse me...Marc not understand tapeless gear.

[wboswell]

wha Is there an onboard pad on the 722?

Sorry, wrong word...  I should have said Trim.  You've got to Trim the gain knobs to attenuate the signal by somewhere around -7dBFS..  or atleast that's been my experience.

ah, makes sense. easy to confuse me...Marc not understand tapeless gear.

mics and pres included, right?

[Zee]

What was your "Line In" gain set at? I ran the V2>722 and the line in I left at 0db it has an adjustable range from -6db - 18db I think.

[marc0789]

wha Is there an onboard pad on the 722?

Sorry, wrong word...  I should have said Trim.  You've got to Trim the gain knobs to attenuate the signal by somewhere around -7dBFS..  or atleast that's been my experience.

ah, makes sense. easy to confuse me...Marc not understand tapeless gear.

mics and pres included, right?

smart*******ass.

[wboswell]

What was your "Line In" gain set at? I ran the V2>722 and the line in I left at 0db it has an adjustable range from -6db - 18db I think.

I guess I was wrong.  Line in must have been set to somewhere around -5 or so on the dial when running the V3 to push decent levels (w/ cANSR on) to a 16 bit device. 

Sorry Marc, you left yourself wide open...

[Todd R]

I used to hit tons of reds on the v3, never an audible clip or even mild distortion. I think they must be off a bit.

It's not off, it's just more accurate than we're otherwise used to.   I have no idea about the 722, but lots of equipment uses analog metering, eg. the sony D7/D8/M1/SBM1.  Meaning that these units sense the voltage level of the analog signal and try to correlate that to OdbFS in the digital realm.  This type of metering isn't all that accurate or precise, and often varies a bit from unit to unit.

The V3 uses digital metering, meaning it is getting the info for the LEDs, including the over LED, from the digital representation of the signal at every given moment (eg, 44,100 times per second, or 48,000 times per second, or whatever).  The over lights light on the V3 by definition when there are 3 or more samples in a row that are 0dbFS.

3 samples at 48k sampling equals one-sixteen thousandth of a second.  If your overs are of such short duration, there is no way in the world that you will hear it.  So it is not that the V3 has so much headroom or that its meters are off.  As folks have said, if you look at the waveform in an audio software package, you will see the clipping.  It's just that if you're just barely setting off the clip indicators, your clips are likely to be so very short that you'll never have a chance of hearing it.

[nedstruzz]

No onboard pad on the 722 however when running line in you can attenuate the level using the gain pots.  The gain can be decreased down to -6, not sure what this represents in db but I would be interested to find out.