Borbely all FET low noise broadband balanced preamplifier PCB one piece

On list is an all-JFET balanced preamplifier based on the design of Mr. "FET", Borbely.

Design Features :

The preamplifier uses low noise high gain JFET at the input stage, followed by common source followers to allow for low impedance driving capability.

The preamplifier contains NO global feedback which make the amplifier very musically and never feel fatique on listening to it.

Due to the pure symmetric architecture, the preamplifier allows unbalanced and balanced input signal and balanced and unbalanced output.

On our test bench, the preamplifier exhibit a superb frequency response( with 10Kohm loading), extending ruler flat from low end to beyond 500KHz, and starts to roll off at 1MHz. This is illustrated in the picture below. The amplifier also exhibits a 'soft' clipping used to be found in tube amplifiers only, which means even the amplifier goes to clipping instantaneously, listener would not be suffered from the metallic clipping noise or may even not notice of the distortion.

Application :

The amplifier can be used as an balanced/unbalanced amplifier, or an amplifier that can convert an unbalanced signal to a balanced signal. By so doing, all stereo power amplifiers can be transformed into a single channel bridge amplifiers.

Specifications :

Input Impedance : 100kohm

Frequency Response : 20Hz to 1MHz +/-3dB ( 10kohm loading)

Default voltage gain : 10 times

PCB dimension : 92mm x 77mm

This is a single channel amplifier PCB. Two PCBs are needed to form a stereo amplifier.

This listing is for one piece of bare PCB. The assembled board is for reference only.

We provide schematic and part list to buyers by EMAIL.

We do air shipping worldwide at US$4.00.