AA> reference books, most of which would be too old for anything new,  
 AA> and I found it interesting to note that the reason that +4 dBm was 
 AA> decided on as a standard level was the fact that there was a 4 dB loss 
 AA> betwine the line and the meter when a VU/VI was place acroos the line. 
Meters weren't designed to load the line that much that I recall.  It has 
been standard practice to use a meter pad between the line and a VU.  While 
the meter rectifier offers some line isolation, the meter movement can to 
some extent act as a motor-generator, effectively passing distortion back to 
the line either as a reverse fed signal, or by changing the dynamic load 
impedance of the meter on the line.  Meter pads, not the same as standard 
matched impedance audio pads, help to isolate meter quirks such as that from 
the audio signal.  
These days it's common to simply use a buffer amp, or a building out 
resistance near dynamic ground driven distribution amp style isolation 
between meter and audio line.  
Terry
--- Maximus 2.01wb
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