9 Tone control Stereo Preamplifier circuit with PCB, Low noise

SEE! Many Tone control circuits. They are the important circuits for the controlled bass and treble effects of the audio system.

We have lists of the top 9 tone control circuits. Which they are an effective low noise tone control circuit.

All components, you can buy parts that used in this circuit are easily available in most of the local electronic stores. And easy to builds with PCB layouts. You should not waste time


Which includes all 9 projects below

Tone control Stereo Preamplifier circuit with PCB

1# Classic Tone Control using 2 Transistors C945

This is a tone control circuit, the small-sized. It is the Mono using two transistors. They are important equipment to increase a sound signal, more power-up.

And, we can adjust the sound with a potentiometer, VR1, VR2, and VR3. To set a complete the sound signal. Or a great treble and bass as well.

The circuit diagram of Classic Tone Control using 2 Transistors C945
Classic Tone Control circuit using 2 Transistors C945

  In the circuit. It is convenient for a novice wants to try to build a Pre Tone control circuit to keep be usable. The prominent point of this circuit be seek the equipment easily, Electronic part replaces can be finished or can antique sheep come to use all right, such as The transistor number C828 may use the number C945 or C1815 or The other all right.

For the level of power supply. We can use  wide range about 12V to 24V at 50mA.

See other detail in the circuit.

The PCB layout and components layout of Classic Tone Control using 2 Transistors C945
The PCB layout and components layout of Classic Tone Control using 2 Transistors C945

2# Stereo Tone Control using 2 transistors C945

See in the circuit below.

This is a Stereo Tone Control circuit using 2 Transistor, 2SC945. Supply Voltage min 12V <80mA. Easy to build, PCB small.

Stereo tone control Preamplifier circuit using two transistors
The Circuit of Tone Control Stereo using C945x2 Transistors
PCB Tone Control Stereo using C945x2 Transistor
PCB Tone Control Stereo using C945x2 Transistor

3# Simple Tone control circuit projects

This may be the First Simple tone control circuit for you. Since easiest to builds, all components are assembled on one PCB. So small size and cheapest.

I like the transistor preamplifiers with tone controls. Because of low noise and classic not outdated.

For students, college students took the basic tone control circuit in particular. But it can really use!  

The tone controls, this is not acceptable. Due to high-quality audio professionals not to use it. Connect popular Audio directly without a sound barrier.

But this system is the most important parameter is the speaker. Your speakers must be highly sensitive, can resonance all audio frequencies range.

But in reality, it is very difficult. To find speakers that feature. Alternatively, designing the sound in the past use the tone control a solution of this speaker is to increase the treble, bass boost. In this project is easy. See the circuit below.

small preamplifier tone control circuit

Simple tone control circuit diagram

Power supply of small preamplifier

Power Supply of Preamplifier Tone control circuit

Working of simple tone control

There is  2 sections, the power supply, and the tone controls.

First, the power supply has diodes D1-D4 is connected as bridge rectifier so can apply power all type AC/DC.
Then, there is capacitors-C12 serves to filter the voltage. Next, will into the voltage control circuit, by having Q4, ZD1, R14, C11 serves to maintain constant voltage as DC Regulator.

Then, a C10 helps filter with together.

Next, come to the tone audio adjustable. The input signal is input to VR1, VR2 through R1, C1 to the base of Q1 by having R2-R6 to control working.

Then, the signal will be sent to the base of Q2 by have R5, R7 is biased working. And the signal will through to C2 to the network circuit, the adjust base-treble by VR4, VR5.

The treble sound includes R9, C5, VR4 controls, and the bass controls include R8, C3, C4, VR3.

Then, the signal will be sent to C6 and increased up by Q3 which includes R10-R13, C7 as a low signal amplifier. The C8 is a feedback frequency offset.

Next, the signal to C9 as the output signal to the power amplifier next step. The feature main This tone can adjust high-frequency very good, sound bright. And no the loudness controls The boost of bass and treble completed, so cut it out.

The design allows for easy builds and use. We put RCA and DC jack and all potentiometers. We only use the RCA cable and apply small AC or DC adapter about 300-500mA to this only.

How to build it

the PCB layout

First, make the PCB as Figure 2 the PCB layout

the component layout

Then assemble all parts on PCB as

Figure 3 the Component layout REAL EASY…

Parts you will need

Resistors ¼ watts +5%

  • R1: 100Ω
  • R2: 150K
  • R3: 82K
  • R4, R6_15K
  • R5: 10K
  • R7: 12K
  • R8, R13: 5.6K
  • R9: 3.3K
  • R10: 8.2K
  • R11: 470Ω
  • R12: 47K
  • R14: 680Ω


  • VR1_100KA Dual Audio Potentiometer
  • VR2_100KMN
  • VR3, VR4_100KB Dual Audio Potentiometer


  • C1, C2, C6, C9, C11: 3.3μF 16V Electrolytic
  • C3, C4: 0.03μ3F mylar
  • C5_0.0047μF mylar
  • C7: 47μF 16V electrolytic
  • C8: 47pF 50V Ceramic
  • C10: 100μF 16V Electrolytic
  • C12: 2,200μF 16V Electrolytic


  • Q1-Q4: 2SC945
  • D1-D4: 1N4001
  • ZD1: 9V 0.5W
  • Others PCB, jacks RCA, jack DC, adapter, etc.

4# Transistors Pre Tone Control Circuit

Here is a classic Tone control circuit. It uses a low noise transistor model. Which this circuit is interesting. Because of the transistor entirely.

Then have a voice good and economize good. See in the circuit below.  this uses 3 transistors.

See in the circuit, is the pre-tone model mono model. If you want to use are the system stereo. You just add another one mono only.

Classic Tone control circuit with low noise transistor
3 Transistors Pre Tone Control Circuit

The prominent point of this circuit. We use wide range power supply voltage only 9V to 18V, should be DC regulator too. See other detail in circuit diagram above.

5# Transistors High-Quality Tone Control Circuit with low noise

Five Transistors High Quality Tone Control Circuit with low noise
5 Transistors High Quality Tone Control Circuit

Designing a power amplifier Circuit that high quality. Something to consider very much is the Preamplifier with tone control.

But friends must not worry. I have this circuit that it use transistors at all work well in specialty model.

There is a constant current source to bias that gets from LED, to help have the stability in temperature work of Q1 and Q2 improve.

The input can take a signal has since 100mV-1V. it does not fear about Over Load, and the very low.

For other parts, you can choose to use general equipment. By sound quality still well.

6# OLD Tone control circuit using 4 low noise transistors

If you have electronics old equipments that keep many long ago year. You do not know to build which Electronic Project good.

OLD Tone control circuit using 4 low noise transistors

I recommended you to build a preamplifier tone control circuit.

It can adjust to reduce the sound Bass,Treble and Volume well.

There is the prominent point that use transistor. But good quality of good sound.

But it is lower output power than the integrated circuit(IC).

The thing that I observes clear be the low noise and bland sound are good.

See in the circuit we can use many transistors number like 2SC945 or 2SC828 or 2SCC1815. Which the price is inexpensive the hardware is other may get not difficult.

The power supply , should choose that be model of DC regulator 12V to 24V.
And building may use Perforated board PCB, which good easy.


7# Classic Tone control circuit using 3 Low noise transistors

See image below, the preamplifier tone control circuit diagram of the home audio stereo is very well. It low noise and sound is beautiful. Because using the quality transistors.

Mono preamplifier tone control using 3 transistors

The Schematic Diagram of Mono Classic Preamplifier Tone control using 3 transistors

It has three transistors, C945, C828 , C1815 or C458. They are old electronic components but useful now.

This circuit is the Mono form, if you want stereo system. You need to make two section R+L.

The VR1 is 100kB for adjusting the treble tone sound. The VR2 is 100K for adjusting the bass tone audio as well.

The VR3 is 100Ka for control volume output. The VR4 is 100KW for control balane sound fo other channel.

The power Supply Voltage used min 12V and min than 80mA. We hope this circuit will do you are enjoying home audio. Good luck.

The PCB layout of Classic Tone control using 3 Low noise transistors

The PCB layout of Classic Tone control using 3 Low noise transistors  

8# High quality Tone Control Mono using 5 Transistors C945

If you are interesting in the stereo amplifier of high quality. You want to listen great sound well, low noise and so loudly.

We can build it in many ways. But usually the audio tone control are made with a transistor that low noise. But it is less power than used IC systems.

I think this circuit will be not that because it has five transistors in diagram. We can also use to boost up a little audio signal.

See In the circuit is mono form. We can use many number of transistors like 2SC945 or 2SC1815 or 2SC828.

Pre amplifier tone control circuit using 5 transistors

Circuit Diagram of High quality Tone Control Mono using 5 Transistors C945

I hope you can find them at general electronic store or inside an old PCB.

You can use the power supply source during voltage 12V to 24V at minimum current at 100mA.

Then, see the PCB diagram for making this project. It is a small size so easy to use.

Also, you can use StripBoard-1 Sided PCB. because it has a few components.

PCB layouts of High quality Tone Control Mono using 5 Transistors C945

PCB layouts of High quality Tone Control Mono using 5 Transistors C945

9# Low Voltage Preamplifier Circuit with Tone Control

If you want to adjust the tone of audio in low voltage states. Is it impossible? Most tone control circuit requires a 12V power supply. Yes, it is real. this is a Low Voltage Preamplifier Circuit with Tone Control.

To begin with this circuit will connect the switch-S1, to apply the power supply to the circuit and the input have audio signal source.

Figure 1 the circuit diagram

How it works

A function of each device do better

Low volts stereo preamplifier with tone control circuit

1. There are C1, C2 and VR1/1 are set the input audio signal to high frequency up, and VR1/1 adjust the treble for the left headphone.

2. The similar the C5, C6 and VR1/2 are set the input audio signal to high frequency up, and VR1/2 adjust the treble for the right headphone channel.

Recommended: Hi Fi audio tone control circuit using low noise transistors

3. When we want stereo sound, therefore, pitched the left headphone is equal to pitched to the right headphone.

So we use the VR1 is Dual Audio Potentiometer Because Changes in the resistance of VR1 / 1 is equal to the resistance of VR1 / 2.

And must to use C1 is equal C5, C2 is equal C6.

If you do not like that pitched voice, it can be modified circuit. By changing the value of C1, C2, C5, C6 and VR1.

But do not forget, the value of C1 is equal to C5 and C2 is equal to the value of C6.

Here are a few related articles you may want to read:

4. Adjusting the bass, the VR2 is dual audio potentiometer. Adjusts the audio signal to a lower frequency, both the left and right channel.

There are R1, R2, C3 and C4 determine the bass for the left headphone, And R3, R4, C7, C8 determine the bass for right headphone.

5. To change the device will change the frequency with C9, C10, C11. And the capacitor C12 acts as bring signal to the left and right.

Through the circuit bass treble adjustment, in to the transistors Q1, Q2, Q3 and Q4. The incoming signal is a signal that is both positive and negative.

When added to the positive halfcycle of C10 to C12 in the past Q2 and Q4 to Q2 and Q4 are amplified by the positive halfcycle.

The negative half is through C9 to C11 at Q1 and through the into the Q3. By Q1 and Q3 to amplify the voice over the negative halfcycle.

It has audio headphone output with both the positive and negative half. As the only input into the frequency of the audio signal changes. The frequency bass sound change is pitched to change that.

Related: High quality tone control circuit low noise

Figure 2 the PCB layout

Figure 2 the PCB layout

the-components-layout-of-Low volts stereo preamplifier

Figure 3 the components layout

Related: Low noise pre tone control circuit using 4558 – NE5532

Parts you will need

0.25 W, +-5% Resistors R1, R3: 18K (brown, gray, orange , gold) R2, R4: 3.3K (orange, orange, red, gold) R5, R6, R7, R8: 47K (yellow, purple, orange, gold)

Dual-layer potentiometers VR1, VR2: 100K type A

Electrolytic capacitors C9, C10, C11, C12_10uF/ 16V

50V, ceramic capacitors C1, C5: 0.0033uF (332) C2, C3, C6, C7: 0.018uF (183) C4, C8: 0.1uF (104)

Transistors Q1, Q3: 2SA1015 Q2, Q4: 2SC1815 S1: SPST Slider Switch Others

Check out these related articles, too:

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