The Guitar pre amp circuit is based on a FET-type BS170, and require very little support components. The polarization of the gate (G, gate) of FET is provided by two resistors R1 and R2. Both resistors are also to set the input impedance of the assembly, which here is close to 500 ohms. The original scheme, the second resistor set at 92K each, and keep the input impedance of less than 50K, which may be too tight to plug the guitar.

BS170, As usual with this type FET or MOSFET power transistors smaller (TO92 plastic housing in particular), you should check the pin manufacturer in the document (datasheet), with consideration for the brand, because the manufacturers do not necessarily offer the same pinouts for the same component model. The BS170 is here using the Motorola brand and pinout is as follows.

The post Guitar pre amp based FET appeared first on Amplifier Circuit Design.

The title is an exaggeration, given that the gain of the circuit is intentionally low. When we talk about pre-amp, you can expect amplification often great … that is not the case here. The purpose of this Guitar preamp circuit is mainly to provide impedance matching to allow the use of long cables between a guitar and an amp, while limiting losses to the maximum audio. Although originally this circuit is provided with a gain setting, we will see that it is entirely possible to delete it.

This TL071 integrated circuit can be replaced easilyby an LT1012, a TL061 (which consumes a little less than the TL071), or even by a TL081. With the components shown in this circuit will get 110k ohm input impedance. If this value seems a little low, you can increase the value of the two resistors R1 and R2. Using two resistors 1MOhm, you will get the input impedance of about 500k ohm.

The post Guitar pre amplifier based TL071 appeared first on Amplifier Circuit Design.