LMA8 Mic/Line Preamplifier
15
Classical Distortion Analysis
The standard analysis of distortion in audio circuits has traditionally been "Total Harmonic Dist Noise".
This method has only limited usefulness in this case, because the distortion of the LMA8 is so low, that it is masked by
noise at higher gain settings.
The LMA8's input noise is among the lowest today's technology can offer, and the distortion of the unique input amplifier
circuit is so low, that it can only be quantified by classical analysis at lower gain settings. At higher gain settings, a FFT
analysis is required.
Dist noise at +10 dB gain
The THD+N is below 0.0004 % in the whole audio range. The measured THD+N result shows good linearity from 20 Hz to
20 kHz; only a slight increase above 2 kHz is seen.
The input noise contribution at +10 dB gain corresponds to a level of approx. 0.00007 %.
Thus it can be seen that the graph mainly represents the distortion of the circuit.
