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Old 4th January 2011
member no 666
Fletcher's Avatar
The difference between +4dBu and -10dBV [commonly shortended to "+4" and "-10"] is about 11.79dB [the difference is based on a logarithmic scale so its not a straight "14 db" as you might think]... what complicates it further is that you're dealing with two different scales [dBu being "dB - un weighted" and dbV - dbVolts"] both with a reference to 0db = .775volts... dBu can be used regardless of impedance, but is derived from a 600 Ω load dissipating 0 dBm (1 mW).

In your case - when you set the input level to "-10" you're increasing the input gain [by 11.79 db]... which originally done to reduce the noise level in "semi pro" equipment [hotter signal in, less noise... also less headroom and a whole bunch of other issues but I have a feeling I've already gone a little too far with the explanation].

Hope this is of some assistance.