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  #1  
Old 06-04-2003, 11:44 AM
el biciclista el biciclista is offline
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Default Can\'t see the waveform of a direct-in guitar signal?

I am recording the direct-in signal from a guitar to a track in ProTools. I go through a standard BSS Audio D.I./Line Balancer box made for this purpose. It converts from high impedence to low impedance, so the signal can be fed to the 192 I/O.

On the track Peak Indicator the maximum signal is -4, which is higher than most of my other tracks. When I play the track with Amp Farm inserted on the track, it plays back fine.

Everything seems to work fine........except, I can't see the waveform for the track. Even when I expand the waveforms until the waveforms on all my other tracks are off scale, I still see only an occasional little bump; otherwise, straight line, like there's nothing recorded in the track.

Why can't I see this waveform? [img]images/icons/confused.gif[/img]
Thanks,
Mike
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  #2  
Old 06-04-2003, 02:54 PM
el biciclista el biciclista is offline
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Default Re: Can\'t see the waveform of a direct-in guitar signal?

Some additional information. I tried taking the guitar DI signal and putting it through my preamp first, then to the 192 I/O. Doing this, I was able to record a signal whose waveform shows. So, apparently the direct signal level is too low for ProTools to display it as a waveform. (FYI, normally the guitar signal is somewhere between a mic signal and line level).

(I don't know why the peak level indicator was giving me bad info. The amplified signal shows a peak at -18. I guess it couldn't deal with the low level signal.)

The problem is: I don't want the guitar signal amplified before I record it. I want it recorded just as it came out of the guitar. Then, later I can send it back out through my Reamp box to the guitar amp and mic the speakers, using different settings until I get exactly the tone I want. The purpose of the recorded DI track is to preserve the guitar output as-is for future reampings.

So, if I don't want to preamplify the DI signal coming in, am I stuck with recording a signal that I can't see in the track? [img]images/icons/shocked.gif[/img]

Thanks,
Mike
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  #3  
Old 06-04-2003, 10:28 PM
Kenny Gioia Kenny Gioia is offline
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Default Re: Can\'t see the waveform of a direct-in guitar signal?

This happened to me the other day and believe it or not, it's normal

You're seeing a higher level because you're seeing the output after Amp Farm.

The only problem is that if you hit it harder you will get more distortion from amp farm.
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  #4  
Old 06-04-2003, 10:57 PM
el biciclista el biciclista is offline
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Default Re: Can\'t see the waveform of a direct-in guitar signal?

Produceher,
I don't quite follow your comment. The peak level I am talking about is the peak level indicator used during recording of the track. So, this (I believe) is showing the peak of the input signal during recording, not the output signal (unless I am really confused). In any case, the peak indicator is not the main issue.

I am asking if, every time I record a guitar direct-in signal, I will end up with a track that displays no waveform (or at best, a slightly bumpy line). Is there any way to "super expand" this track so I can see the waveform?

If there is no work-around, it is not the end of the world. But it is inconvenient, to say the least: I can't edit in the track, I can't spot glitches visually, etc. Just a pain, no catastrophe. I was just hoping someone else had encountered the problem and solved it somehow.

Thanks,
Mike
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  #5  
Old 06-04-2003, 11:49 PM
Extreme Mixing Extreme Mixing is offline
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Default Re: Can\'t see the waveform of a direct-in guitar signal?

I think the mistake you are making is that the DI does not produce a balanced line level signal that the 192 wants to see. It produces a balanced mic level signal, which is WAY lower in level. That's why you can't see the wave form. When you insert a plug in the Pro Tools mixer, it changes the level of the channel meter on the mixer. If you insert an EQ on a channel, then bring the level up or down, you will see the level differences reflected in the channel meter.

That's what is happening here. You are recording a very low signal and looking at the meter readings produced post the amp farm gain stage. The wave form graphic is a more accurate representation of the level you are actually recording into Pro Tools.

If you like the sound, then I guess you'll have to leave it alone. But next time use a Mic pre with your DI, set your level, then add amp farm.

You may be the one person on this forum who has not captured the full dynamic range of the signal down to the noise floor, per Nika's discussions. But if you like the sound, what are you gonna do?
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  #6  
Old 06-04-2003, 11:58 PM
Extreme Mixing Extreme Mixing is offline
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Default Re: Can\'t see the waveform of a direct-in guitar signal?

el biciclista,

To answer your question, you could change the way the wave form looks by adjusting the wave form magnification or by using the audio suite gain plug in to add 20 or 30 db of gain. If you don't want to change the sound, duplicate the track and add audio suite gain to the copy, then group those two tracks and use the bigger one as your visual guide while keeping it muted.
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  #7  
Old 06-05-2003, 05:48 AM
jho jho is offline
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Default Re: Can\'t see the waveform of a direct-in guitar signal?

Yeah what EM said. You need more gain going in, run it thru a pre.
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  #8  
Old 06-05-2003, 06:52 AM
Kenny Gioia Kenny Gioia is offline
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Default Re: Can\'t see the waveform of a direct-in guitar signal?

Quote:
Originally posted by jho:
Yeah what EM said. You need more gain going in, run it thru a pre.
<font size="2" face="Verdana, Arial">Yeah
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  #9  
Old 06-05-2003, 09:07 PM
el biciclista el biciclista is offline
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Default Re: Can\'t see the waveform of a direct-in guitar signal?

Thanks guys for (1) solving the problem and (2) clarifying for me what I am reading on the peak indicator.

I will run through the preamp with a 15-20dB gain while recording the DI signal. Then, when I reamp back out to my guitar amplifier/speakers to mic for the final guitar track, I will trim the signal to the Reamp unit by the same gain amount. (I assume this 20dB up/20dB down will not alter the basic signal, as long as I have plenty of headroom).

Thanks again, [img]images/icons/smile.gif[/img]
Mike
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  #10  
Old 06-05-2003, 09:29 PM
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Alécio Costa Alécio Costa is offline
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Default Re: Can\'t see the waveform of a direct-in guitar signal?

Ys, folks are right. While performing fade-outs it was fery funny to seee almost no waveform and the huge ampfarm sound output.lol
Yes, I was also recording Tru a Klark Dbox.
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