Hello again, my english is very poor sorry , and i'm a newbie too so please, be patient well, here's the dilema: i made an RCA mic pre, LS10x as input xformer , it works fine, no noise, no hum, everything's hunky dory, but i want to use 4 different input impedances, 50, 150, 250 & 600 ohms. The thing is that i want to put an H pad on the input, -10db, so i don't know the values for each pad, i need 1 pad for each impedance. i've tried the h-pad calculator on http://mcsquared.com/hpad-calc.zip , but it gives me resistor values that doesn't exist, so i don't know how to calculate the 4 h-pads that i need. thanks again kev, your site makes my life easier!!! i'll send you some photos soon... if you want to see my page... http://elotroyo.com bye!