Stereo Hi-Fi Headphone Amplifier Circuit

A simple yet extremely hi-fidelity type Stereo Hi-Fi Headphone Amplifier Circuit  can be studied in the following article which will give you an of the world experience once you build it and start using it

The four diodes in rectifier bridge B1 are bypassed with rattle suppression capacitors to ensure minimum noise on the supply rails to the opamps.

This makes it possible to feed the 15V regulator from the raw voltage across Ca (+) and C10 (-) of the existing l8.5 V supply while the inputs of the volume control of the head- phone amplifier are driven direct from the outputs of IC4 l l (R) and IC4’ (L).

At the l input side, few problems are i expected to arise when using gold-plated phono sockets mounted onto a separate ABS or epoxy plate.

When a good quality, insulated, 6.3 mm, stereo headphone socket proves , unobtainable, the nearest alternative is a non-insulated type, whose common tag is connected direct to the ground point on the PCB, between C1 and C18 to effect central earthing.

Opamps IC1 and IC; should be soldered direct onto the PCB, and are preferably fitted with a DIL-type heatsink.

Provision has been made to screen the amplifiers and the supply on the Q board by means of two sheets of brass or tin plate, which are mounted vertically onto the dotted lines, and secured with  three soldering pins each. Series regulators T1 and T2 ( can do without a heat-sink.

When the board is complete, , its underside should be  thoroughly cleaned with a brush dipped into white spirit or alcohol to remove any residual resin.

The Stereo Hi-Fi Headphone Amplifier Circuit  can function optimally only if great care is taken both in the choice of the components and in the construction on PCB Type 87512, details of which are shown in Fig.2.

As already stated, the headphone amplifier is suitable for building into the Top-of-the-Range Preamplifier.

Next, the track side is sealed with a suitable plastic spray. When possible, use insulated sockets for the stereo input and output of the amplifier. At power—on.

Mains-borne interference and clicks from St are suppressed in varistor R9 and high-voltage capacitor C19.

Mains transformer Tr1 is preferably a toroidal type fitted behind a metal screen to ensure minimum hum and other interference picked up by the amplifier inputs.

Presets Pz and P! are trimmed for minimum offset voltage at the respective amplifier output—this is likely to require a very sensitive DMM.

The headphone amplifier can be terminated in 100 Q to 1 10Q, and is therefore perfect for use as a high-quality line driver also.

The outputs are sh0rt—circuit resistant.

Stereo Hi-Fi Headphone Amplifier Circuit