Latest Publications

Small Stereo Amplifier Circuit with Bass Treble Controls

A total, independent, little and reduced Hi-Fi stereo enhancer circuit with bass, treble, volume control is introduced in the accompanying article.

This little reduced stereo enhancer can be utilized for intensifying music from cell phones, PC USB, Ipod or any source fit for creating as low as 50 millivolt signal.

Because of the high bass and high treble control office, a couple little subwoofers can be utilized for getting an improved Hi-Fi music reaction from any normal music input.

Bass Treble Circuit 

We will start with a high addition, high devotion bass treble controller circuit which shapes the principal phase of this reduced table intensifier plan.

Transistors T1 and T2 are intended to work like a high information impedance voltage intensifier and with a low yield impedance.

At the point when the focal slider arm of the preset P1 is changed in accordance with its full 1 k limit, the information affectability alongside the little 5 watt enhancer finds a good pace mV for the 12 - volt adaptation, and when a 4 ohm speaker is utilized as the heap. This may become 200 mV if the stock voltage is expanded to 17 V and the speaker is of 8 ohm esteem.

On the off chance that you need a more prominent info affectability, you can utilize the preset P1 esteem lower than 1 K. In the event that you are intrigued to incorporate a particular range for the info affectability, all things considered you can put a selector switch with various resistors at the contribution for choosing the ideal information affectability extend.

The equation for ascertaining the resistor esteems is demonstrated as follows:

Rx = 500 x Vin/300 - Vin

where Vin portrays the info RMS estimation of the voltage in mV. The recipe can be adequately utilized for all info voltages extending from 5 mV to 250 mV.

The transistors T3 is arranged as a Baxandall tone control circuit. The 1 nF capacitor between T3 authority and ground line is incorporated to improve adjustment and limit motions.

PCB Design for the Bass Treble Control Board

Minimal 5 Watt Stereo Amplifier 

The above clarified dynamic high addition tone control can be coordinated with an individual little smaller enhancer, as depicted beneath. This a small 5 watt form.

The yield from the bass treble module must be coordinated with the contribution of the accompanying enhancer circuit.

How it Works

Transistors TI and T2 is arranged to work like a direct coupled voltage intensifier. Resistor R6 and diodes DI/D2 choose the degree of inert momentum or the peaceful ebb and flow utilization of the semi corresponding driver organize T3/T4 alongside the yield arrange T5/T6.

The resistors R7 and R8 values are chosen such that the yield transistors are either scarcely one-sided ON or simply cut off. This is thusly dictated by the increase of the transistors utilized.

C3, C5, C6 and R3 are incorporated to guarantee legitimate soundness of the plan. The information affectability of this 5 watt intensifier is around 400 mV when a 12 - volt supply input and a 4 Ohm speaker is utilized burden, and it is 600 mV when the inventory is 17 V and the speaker obstruction is 8 Ohms.

It is conceivable to improve the increase of the speaker by decreasing R4 however this may not be a smart thought, since this may prompt unsteadiness and higher bending levels.

The accompanying consideration must be kept up for the structure design while introducing the enhancer board inside the skeleton.

The negative wire of the amplifier ought to be associated straightforwardly with the principle ground of the force supply and not to the speaker PCB. This link must be kept standoffish from the circuit board.

Every one of the stockpile links appeared in the outline must run independently to the board over the predefined areas.

The yield area and the wiring of the board must be all around separated and avoided the info wiring and phases of the board.

To maintain a strategic distance from earth circles, every single stock wire must be exclusively associated and independently wired to the force supply from the board.

Parts List 


R1, R2 =100 k

R3, R5= 4k7

R4 = 470 Ohms

R6 = 33 Ohms

R7, R8 =5611

R9, R10 = 0.2 Ohms

R11 =1 k

R12 = see table


C1 = 2,2 ยต, 16 V

C2 - 10011. 16 V

C3= 10n

C4= see table

C5,C6 = 47 n


T1,T3 - Any NPN little sign universally useful

T2,T4 = Any PNP little sign universally useful

TS,T6= 2N1613

D1,D2 = 1N4148 

heatsinks for TO - 5

R12, C4 Selection Table

Stereo PCB Design 

The accompanying outline exhibits the directed force supply circuit for the minimized stereo enhancer circuit.

Transistors TI and 12 are wired as a Darlington pair with the goal that it works like a composite high addition, high force producer adherent transistor.

The base reference voltage for this producer devotee is fixed through Z1 which might be chosen as a 13 V or 18 volt zener for getting a 12 V or 17 volt supply separately.

Because of lower input yield differential T2 should scatter next to no measure of intensity as warmth and in this manner a heatsink may not be basic.

No comments