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Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: MLKLuke on April 10, 2007, 02:44:51 PM

Title: JB3 +/- AD20 Comparison
Post by: MLKLuke on April 10, 2007, 02:44:51 PM
hi,
I just received an AD20 to insert in my rig (AT853 > 3Wire BBox > JB3)

I will test the new rig with AD20 next week but for the moment I made a simple/quick test putting my mics in the "taping hat" in front of my cd-stereo recording an audio track from a cd

I recorded it with AD20 in the chain with mid/high gain settings (+0db in JB3 and mid/high setting with AD20 gain knobs) and then without it with the JB3 gain @ +12db. Then I normalized both tracks with the same default settings in Soundforge (normalize @ 0db by average rms) and here they comes [2 flac files / 16bit-44.1Khz]:

http://www.sendspace.com/file/or9g3z

please let me know what do you think about them. I know maybe this is not such a relevant test but I can't do a test in the field now

Title: Re: JB3 +/- AD20 Comparison
Post by: Brian Skalinder on April 10, 2007, 04:33:09 PM
I recorded it with AD20 in the chain with mid/high gain settings (+0db in JB3 and mid/high setting with AD20 gain knobs) and then without it with the JB3 gain @ +12db

FWIW, with the AD-20 in the chain the AD-20 outputs a digital signal and the JB3 inputs the digital signal from the AD-20.  The gain level on the JB3 (+0dB) is only active during analog input and shouldn't impact the recording when running optical-in to the JB3 from the AD-20.
Title: Re: JB3 +/- AD20 Comparison
Post by: MLKLuke on April 10, 2007, 04:38:50 PM
you're right, sorry  ;)

any opinions about the audio files?
Title: Re: JB3 +/- AD20 Comparison
Post by: mmadd29 on April 10, 2007, 07:30:11 PM
I recorded it with AD20 in the chain with mid/high gain settings (+0db in JB3 and mid/high setting with AD20 gain knobs) and then without it with the JB3 gain @ +12db

FWIW, with the AD-20 in the chain the AD-20 outputs a digital signal and the JB3 inputs the digital signal from the AD-20.  The gain level on the JB3 (+0dB) is only active during analog input and shouldn't impact the recording when running optical-in to the JB3 from the AD-20.

I just got an AD-20 to run with my JB3.  I tested with my stereo jacked up and found the meters on JB3 were high, like 3/4 with the AD-20 with low output.  Turning up the output put the levels into clipping.  I found with analog the meters at 3/4 is good.

My concern is that at a show I'll always be clipping.  i know this can't be the case.

Are the meters worthless in optical mode??

Thanks
Title: Re: JB3 +/- AD20 Comparison
Post by: shayne on April 10, 2007, 09:54:15 PM
No, the meters work you just have to watch them they are small, the AD-20 starts out w/ gain before you even add any w/ the pots, read up somewhere it tells you what the ad-20 puts out for gain at the lowest setting, I found out the hard way and had to use 10 decibal pads from there on, this ad-20 > jb3 is a good situation for a view meter like the svu-1 or 2, line out of the jb3 to keep more accurate levels.
Title: Re: JB3 +/- AD20 Comparison
Post by: MLKLuke on April 11, 2007, 01:19:03 AM
opinions about the audio files?  :-[