>Using a 100K/220 input ratio, THD is about 0.5% for a 3080 with a 10 volt >peak to peak sine. I measured it with an Audio Precision System 2. THD+noise was exactly 0,35% at the conditions you mention. See http://www.idg.se/personal/bergfors/bergfotron/vca/ca3080%20vca%202.htm /Jorgen