Re: +4 dBu or -10 dBV?
As other's have said, no. Mic levels vary widely depending on the type of mic and the source. I find that with most singers a mic like a Beta58 or an AKG D880 needs between 25 and 30dB of gain to get it to about 0dB on a modern mixer. Knowing that most mixers are setup to produce +4 dBu on the outputs when the meter reads 0, that tells me that the level of a mic with an average source is in the -26 to -21 dBu range and lower. Most mic preamps are capable of upwards of 60 dB of gain, so you can do the math there.
The thing that makes the largest difference between mic and line is the typical impedance involved. Most mics are in the "hundreds of Ohms" region while most mic preamps offer one to a few thousands of Ohms input impedance. Line level outputs vary, I've seen specs as low as 50 Ohms and ones as high as 1k Ohm while line level inputs are in the 10s of thousands of Ohms.
Another category are instrument levels which for guitars can also vary widely, but output an impedance of 10k or even 100k Ohm is not uncommon and an input impedance of 1M Ohm would be ideal.
As other's have said, no. Mic levels vary widely depending on the type of mic and the source. I find that with most singers a mic like a Beta58 or an AKG D880 needs between 25 and 30dB of gain to get it to about 0dB on a modern mixer. Knowing that most mixers are setup to produce +4 dBu on the outputs when the meter reads 0, that tells me that the level of a mic with an average source is in the -26 to -21 dBu range and lower. Most mic preamps are capable of upwards of 60 dB of gain, so you can do the math there.
The thing that makes the largest difference between mic and line is the typical impedance involved. Most mics are in the "hundreds of Ohms" region while most mic preamps offer one to a few thousands of Ohms input impedance. Line level outputs vary, I've seen specs as low as 50 Ohms and ones as high as 1k Ohm while line level inputs are in the 10s of thousands of Ohms.
Another category are instrument levels which for guitars can also vary widely, but output an impedance of 10k or even 100k Ohm is not uncommon and an input impedance of 1M Ohm would be ideal.
~:-D~:grin: