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Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: MLKLuke on July 18, 2013, 05:21:55 PM
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hi guys,
I just received a brand new CA9200 3wire preamp (this one: http://taperssection.com/index.php?topic=163130.0) and I tested it on the filed yesterday night for BRMC + The Killers
well as soon as I transferred the recordings on my pc and opened the files something seemed strange in the waveforms. they seem to be almost perfectly aligned on a precise level (around -5/-6db...that is the level that my R09HR was showing on its vu meter on the screen). these waveforms are really different from all my previous recordings. here's a couple of screenshots of a recording made last week at the same venue, same taping spot (15-20mt from side stage stacks), same audio stacks (it's a common venue that hosts multiple summer shows). As you can see the waveform of the recording made with AT853 > 3Wire BBox (my standard rig from 2006 to yesterday) shows much more dynamic. The AT853 > CA9200 seems somewhat flat.
Some infos:
with my classic AT853 > 3W Bbox > R09HR i usually set edirol's level from 60 to 75 depending on the sound volume I get from the stacks from my taping spot
considering that R09HR unity gain is supposed to be around +35db I set it that way yesterday and I setup CA9200 @ +30db. As i explained before the levels on the edirol were not going over -5/-6db, my usual goal/safe zone.
I was using a brand new DURACELL PROCELL 9V battery on the CA9200. HPF swith was OFF. 4.7k Mod Switch was ON.
R09HR: Limiter/AGC switch > OFF
I need to understand what happened to know if it's a bad thing (first of all) and if so...to avoid it in the future. Chris told me to set CA9200 at +15db instead of +30db and that I slightly overloaded my input but I set it at +30 because when I set it at +15db I was only getting around -12db on my edirol's levels and it's a bit too low. How can I know if I'm overloading my input if the levels on the recorder's display are ok? is it a blind game?
hope someone can make some light on this for me :)
AT853 > 3WBBox > R09HR (Line-IN) screenshot >> http://www.mlk.altervista.org/3wbox.png (http://www.mlk.altervista.org/3wbox.png)
AT853 > CA9200 > R09HR (Line-IN) screenshot >> http://www.mlk.altervista.org/ca9200.png (http://www.mlk.altervista.org/ca9200.png)
finally a link to a sample of one of the recordings (raw/unedited): https://www.dropbox.com/s/k8jfs5ht2kjljx8/killers_sample_ca9200.mp3
thanks in advance
@chris: it's not that I do not trust you, it's just that I need to understand this thing very well before using this preamp for future gigs without overloading risk
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First question is did you go Line-In or Mic-In? Mic-in is better. Also, at what level did you have the R-09HR set for?
You don't have to fly blind, you just gotta keep learnin'. No worries, but +30 is a lot of gain on the CA-9200, especially with amplified music, I would imagine that would be the case here. If at the +15 setting you were getting levels in the -12 ballpark on the R-09HR at 24-bit, then you would have been fine just to raise it in post. The CA-9200 is allowing the mics to perform properly by providing power, but it is also a way to control how the signal is going to be outputted. The CA-9200 can handle real high SPL and it is a solid performer, so I would not worry about it not working properly, just gotta turn it down a bit.
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hi there,
I always used LINE-IN as everybody suggests to do when running mics + battery box or preamp into the recorder
ok so I guess I have to get used to this new device. I always tried to get levels at around -8/-6db on my R09HR using my 3Wire Battery Box and never had problems. If I understand I have to try to keep the levels at around -12db with this new CA9200 cause it gives a good amount of gain (while 3wire BBox does not) and it can overload edirol's input. So I had no problems with my 3Wire Bbox because all the gain was provided by the Edirol itself so it could not overload...isn't it?
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Go LINE IN on the R09, not mic in. Drop the gain on the 9200 down to about +20 (+30 is too high for loud amplified music going into the R09). The R09 does not like a hot signal, so better to run the 9200 lower and increase the input level a bit on the R09 to get peaks somewhere between -12 and -6. I ran an Nbox>R09 for awhile. The Nbox provided around +18-20 gain and I would brickwall the R09 on rare occations.
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I too use an r09hr I will run some tests on it next week to see what the max input is that it can handle. and get back to you. if you want I will make a new thread or post in here. so everybody has the info.
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thanks chris and guys for the help :) will try @+15db and keeping levels on recorder at -12db tomorrow
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Here's some of Guysonics info on R09HR may be helpful for you.
http://www.sonicstudios.com/r09hrrev.htm
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thanks for the link...I do not understand the INPUTS Table...can someone explain that? thanks :)
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You should read this, hopefully it explains things a little better.
http://taperssection.com/index.php?topic=152494.0
The rec level adjustment on the recorder comes after you are already distorting. The concept of "unity gain" on the recorder doesn't matter if you are hitting it with too strong of a signal. If you back off the gain on the CA9200 to +15 dB you can adjust the rec level on the recorder higher so you get levels closer to your desired -6 dB.
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Here's some of Guysonics info on R09HR may be helpful for you.
http://www.sonicstudios.com/r09hrrev.htm
The table on GS's website only relates to mic input not line input.
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with my classic AT853 > 3W Bbox > R09HR i usually set edirol's level from 60 to 75 depending on the sound volume I get from the stacks from my taping spot
considering that R09HR unity gain is supposed to be around +35db I set it that way yesterday and I setup CA9200 @ +30db. As i explained before the levels on the edirol were not going over -5/-6db, my usual goal/safe zone.
And to clarify - the setting of 60 to 75 that you were using with the battery box is not "dB" and the "unity gain" of the R09HR is not 35 "db". The numbers for rec level are not "dB". It seems you picked 35 as the rec level and 30 dB on preamp thinking that was equivalent to 65 on the recorder with jsut the battery box and it's not. The rec level number is just that, a "number". In the Sonic Studios link, the table shows that for line-in the rec level setting of 1 represents -12 dBu and the level of 80 is +28 dBu. So that's 40 dB of range for the 1-80 number.