Hello! I need help from all of the forum. I need to do some simulations in PSpice, but I can not use this software. I need to find the common mode gain and differential mode gain of the first circuit of this site (with Rbias = 4.27k): http://www.dee.feis.unesp.br/graduacao/disciplinas/ele1076/preparatorio-2-2009-1.pdf I need to do this urgently! Thank you. Excuse me for English, but I am Brazilian. Wagner.