** The TS-440S I use for driving a 2, 3-500Z amplifier produces more distortion than the 3-500Zs. I want to increase the amplifier idling current in the 440 to improve linearity. VR1 and VR2 apparently set the idling current for the driver and final amplifier. Can anyone describe how to gain accrss to the Final Unit PCB ? - Rich..., 805.386.3734, www.vcnet.com/measures.