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Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: tms on January 19, 2005, 12:14:47 PM

Title: Expected level from a battery box?
Post by: tms on January 19, 2005, 12:14:47 PM

Hi,

I'm a newbie taper using a stereo gooseneck mic and SP-SPSB-1 both from Sound Professionals.  Last year my recorder was a portable SONY MD player with a Line-in connection.  At two outdoor concerts and one indoor Bela Fleck show the manual recording level on the MD recorder needs to be set almost at its maximum setting, +30dB to get 3 or 4 bars out of 5 on the level meter.  Does this seem right?  Doesn't that mean the signal from the battery box is tiny, like 0.001 V peak to peak ?

I just got a JB3 and would like to use the same mic and battery box but the JB3 only goes up to +12 dB. 

Seems like digitally amplifying a tiny signal is a bad idea.  Is something wrong with the battery box?

Thanks for any help.

Todd
Buffalo, NY

Title: Re: Expected level from a battery box?
Post by: jk labs on January 21, 2005, 11:08:22 AM

Quote from: tms on January 19, 2005, 12:14:47 PM

Hi,

I'm a newbie taper using a stereo gooseneck mic and SP-SPSB-1 both from Sound Professionals.  Last year my recorder was a portable SONY MD player with a Line-in connection.  At two outdoor concerts and one indoor Bela Fleck show the manual recording level on the MD recorder needs to be set almost at its maximum setting, +30dB to get 3 or 4 bars out of 5 on the level meter.  Does this seem right?  Doesn't that mean the signal from the battery box is tiny, like 0.001 V peak to peak ?

I just got a JB3 and would like to use the same mic and battery box but the JB3 only goes up to +12 dB. 

Seems like digitally amplifying a tiny signal is a bad idea.  Is something wrong with the battery box?

Thanks for any help.

Todd
Buffalo, NY

Hi there.

30 dB gain is like x25. If the recorder operates with 2.5 Vpp internally to get near a full scale word from the ADC then that means the level from the batt box is 1/25 of that or 0.1 V peak to peak. (Assuming the gain specified is all the gain there is between the the line input and the ADC port).   

This is all fairly consistent in fact with a mic/box overall sensitivity of -20 dB re 94 dB SPL etc ...and somewhat puny levels from the PA stack.