Topic: How hot signal can preamp take?

[TimSmith]

Hope my English is good enough to explain this.

Recently I recorded very loud metal show with CA-14 -> bbox -> m10. The settings were: mic in, low sens, gain on 2.5, levels peaking at -12db.

Now I wanna use my CA-9200 preamp to tape a show (not very loud one) at +30db setting ('cos +15 may not be enough). I need to figure out how loud signal can preamp take without distorting. I take my ipod (with a certain song playing) plug it into m10 and set it to the volume (lets say to the point X), so with the same settings on m10 as for the metal show, I get same -12db levels. I conclude that amplitudes of the signals are more or less identical: [certain song on ipod on volume X]=[signal from the mics on the metal concert]. Then I plug [sertain song on ipod on volume X] into preamp on +30 setting and it does not distort.  I make the final conclusion that preamp on +30 will not distort on shows less loud than that metal one (when using same mics).

From my noobish point of view everything seems correct, but is it? Is there a catch?

Thanks in advance!


Tim

[fmaderjr]

Recording a show that is not too loud with CA-14's > CA-9200 > M10, you should be fine with the CA-9200 set to +30 (with volume control to the max).

Unity gain is supposed to be somewhere in the 3 to 4 range on the M10, so in the future, I would recommend keeping the M10 set at 3.5 instead of 2.5. It's best not to set a recorder much below unity gain because it requires more gain from the pre and, at a very loud show, could cause the pre to clip even with the meters staying below 0 dB. I doubt if that would be especially likely to happen with a setting as close to unity as 2.5, but it's always best to take all available precautions.

[Drgiggles1]

Go line in with the pre and set the M10 on 4 (and low sensitivity). Get the rest of the gain you need from the pre amp.

[TimSmith]

Thanks for replies, guys! Actually i already knew all of the above. And with CA-9200 the only way is to set the pre to +15 or +30 (no settings in the middle) and get the rest of the recorder. At least for s****th situations. I need to set it before the show.

And yes, with line in gain set to 2.5 I will need to set the pre at +30 to get -12db levels. Which is too much for loud shows. (on the metal show i was running mic in, without a pre. 2.5 is ok in this case)

The main question is: can I use the test described in the first post as  guideline for my taping?

[Church-Audio]

Thanks for replies, guys! Actually i already knew all of the above. And with CA-9200 the only way is to set the pre to +15 or +30 (no settings in the middle) and get the rest of the recorder. At least for s****th situations. I need to set it before the show.

And yes, with line in gain set to 2.5 I will need to set the pre at +30 to get -12db levels. Which is too much for loud shows. (on the metal show i was running mic in, without a pre. 2.5 is ok in this case)

The main question is: can I use the test described in the first post as  guideline for my taping?

With my 9200 its not so much a problem with the input level the preamp can handle its more a situation of how much input your recorder can handle if you want to avoid distortion set your recorder to what ever setting is unity gain and adjust the 9200 to get to -10 db on your VU then normalize in post. That should get you a good clean recording. Provided your mics dont overload.

[TimSmith]

Ok, thanks, Chris. Now I'm sure about +30db.

[bugg100]

[/quote]

With my 9200 its not so much a problem with the input level the preamp can handle its more a situation of how much input your recorder can handle if you want to avoid distortion set your recorder to what ever setting is unity gain and adjust the 9200 to get to -10 db on your VU then normalize in post. That should get you a good clean recording. Provided your mics dont overload.
[/quote]

Truth!