Taperssection.com
Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: KLowe on December 02, 2007, 03:07:20 PM
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Hey yall.
I have an apogee mini mp and run into a R-4. I've run it a few times and it comes out pretty good but I keep getting funky wav forms. I'll post a pic of the waveforms in a minute. Just wondering. How do you guys run a pre into an R-4?
What levels do you set the R-4's gain at?
What levels do you set your external pre at?
Let me know what you think of the waveform. CLipping? Brickwall? Nothing wrong?
No clipping detected from mini-mp or R-4 during the show
(http://i64.photobucket.com/albums/h184/mofrogeek/DSC03140.jpg)
(http://i64.photobucket.com/albums/h184/mofrogeek/DSC03139.jpg)
Kevin
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zoom waaaaaaaaay in on the waveform, kevin. Until you can see each individual peak. Then you'll know. If it is blocked off at the top, you clipped. If not, your ok. I've had waveforms look like yours and were fine. I've had waveforms that looked much more dynamic and were clipped.
was it w00kgroove you taped on Thursday ;)
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Kind of looks like you may have the sensitivity set to high on the R4. When I ran a pre infront of the R4 I kept the sensivity at it's lowest setting (turned all the way to the left) and ran the pre at around 30-36 (portico). Now that I am running just the R4 the sensitivity is set in the middle with the gain knob running at around 12:00 or a little less.
Any of that make sense or help?
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The wav's in that pic look fine. What makes you think they are "funky"? As already mentioned, you can't judge the waveform till you zoom in a bit.
you're not even hitting -3 on the peaks, so you did not clip the R-4.
Your best bet is to have the gain on the r-4 set at zero, then use the gain on the pre to get the levels you want. If you are running 24/96 then peaking at -3 is fine, that way you have headroom when you need it.
JAson
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A limiter ridden pretty hard and set to -3db would result in wavforms like that...
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At first glance, it does look like there's some pretty hard limiting going on in those waveforms. The switchable limiter on the R-4 (which I rarely use) creates a more gradual ceiling than that, however -- it kicks in at -10dB with a max 1:3 compression ratio.
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limiter makes sense to me. the recording sounds fine with no detectable distortion.
Guess it got turned on and I forgot about it.
thanks for the input yall..
Kevin
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Don't forget that if this was a PA gig, depending on the style and the FOH, the house may be compressing the final PA mix in a big enough way to cause waveforms like that -- after all you're just recording what's coming out of the house. I've personally recorded shows that looked like that. If it sounds OK, and the limiter was off, and you don't see clipped peaks when zoomed way in, then I bet it just sounded like that.
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looks brickwalled.
when the levels are sqaured off, and you are not clipping...that is preamp overload (or the limiter, as pointed out)
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It's easy to overload the R4 line inputs I've found.
Hopefully you are using the TRS inputs and keeping the R4 at minimum gain. Also should hold the mini mp combined output level at 3:00 or lower. Then adjust mini mp L/R gain to desired digital level on the R4.
Good luck!
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I'm wondering at using a preamp in front of the R4. When I traced the circuit I noticed that line in merely attenuates before putting the signal through *the same preamp*. So, if you're putting external gain there, you're just going through two pres instead of one. I'm not sure if this is any better than going direclty into the R4.
Notes:
- The R4 pro may have a different gain stage (I hope so...).
- I don't know what happens *after* the preamp. There is a chip NJM 5019, and I have no idea what that does.
(perhaps the limiter?).
Comments welcome...
Richard
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beats me.
I do know that the line in is just a-20db path trough the same preamp, as you stated.
when I used to run mine (and I did it every which way), I'd run my m248 in front w/the gain nearly "off" on the R4. worked out pretty well at the time.
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I'm wondering at using a preamp in front of the R4. When I traced the circuit I noticed that line in merely attenuates before putting the signal through *the same preamp*. So, if you're putting external gain there, you're just going through two pres instead of one. I'm not sure if this is any better than going direclty into the R4.
if you like the sonic character of the first pre amp then there could be some benefit.
--says the guy thinking of selling his V2. ;D
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are you running line in or mic in on the R-4. looks like you were running mic in and it overloaded pretty bad.
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I have also recorded shows w/the FOH guy over compressed the sound and the .wav files look like squares (but sound OK)