Abstract: A stringed instrument and preamplifier combination where the preamplifier simulates the sound of analog tube amplifiers, and contains only solid state active devices. The preamplifier uses a diode branch with the diode biased into its forward active region and as a non-linear resistive element to provide signal-modulated gain on the operational amplifier gain stage. An alternative embodiment supplements the diode branch with series and parallel resistors as additional design optimization parameters. Another alternative embodiment adds symmetrical output clipping diodes to simulate a vacuum tube push-pull output independently of the diode branch.

Abstract: A stringed instrument including a body having a top surface defining a picking area; a bridge supported by the top surface at one end of the picking area; a neck extending from the body at an opposite end of the picking area; and a plurality of strings extending in substantially parallel paths over the picking area. Each pickup is disposed under a different associated one of the strings and a support mechanism mounted on the top surface and adapted to accommodate movement of each pickup in a path within the picking area and parallel to its associated string.