Stereo Tone Control Component List

INTEGRATED CIRCUIT

• TL072 : 2
• TL071 : 1

RESISTORS All 1/4W

• 22K ohm (red, red, orange) : 10
• 10K ohm (Brown, Black, Orange) : 10
• 1K ohm (brown, black, red) : 3
• 100K ohm (brown, black, orange) : 3
• 100 ohm (Coffee, Black, Coffee) : 4
• stereo/dual potentiometers 100K ohm : 3
• stereo/dual potentiometers 10K ohm : 2
• mono/single potentiometers 10K ohm : 2

CAPACITORS

• 1uF/25V electrolytic capacitor : 4
• 10uF/25V electrolytic capacitor : 1
• 4.7uF/25V electrolytic capacitor : 2
• 6.8nF (682) polyester capacitor : 2
• 1.5nF (152) polyester capacitor : 2
• 47nF (473) polyester capacitor : 2
• 1nF (102) polyester capacitor : 2
• 100nF (104) polyester capacitor : 4
• 2200uF x 25 V electrolytic capacitor : 2
• 1uF nonpolar capacitor (105) : 5

Stereo Tone Control PCB Layout and Component Placement

Power Supply Circuit

The power supply type for the stereo tone control is symmetrical and regulated and on its output we use +15 and -15 VDC. The LM7815 will deliver stabilized +15VDC and the LM7915 will deliver stabilized -15 VDC. For symmetrical source, the TL072 VCC range will be 7V up to 36V, so you may use a pair of regulator IC LM7805/LM7905 up to LM7815/7915.
Below is the schematic diagram, pcb design and component layout:

This is the simple and low cost 3 channels mini audio mixer circuit diagram. This circuit supplied using 9V power supply. There are high/low-sensitivity switchable inputs for each input channel and each channel used low noise and high gain transistor of BC550C.

Components list:

P1,P2,P3_________5K Linear Potentiometers

R1,R11,R15_____180K 1/4W Resistors
R2,R12,R16_______2M2 1/4W Resistors
R3,R13,R17_____750R 1/4W Resistors (See Notes)
R4,R14,R18_______1K 1/4W Resistors
R5______________15K 1/4W Resistor
R6_____________220R 1/4W Resistor
R7_______________1K5 1/4W Resistor
R8_____________820R 1/4W Resistor
R9_____________150R 1/4W Resistor
R10____________100K 1/4W Resistor

C1,C6,C8_________1uF 63V Polyester or Electrolytic Capacitors
C2,C4,C7,C9____100uF 25V Electrolytic Capacitors
C3,C5__________220uF 25V Electrolytic Capacitors

Q1,Q4,Q5______BC550C 45V 100mA Low noise High gain NPN Transistors
Q2____________BC547 45V 100mA General purpose NPN Transistor
Q3____________BC557 45V 100mA General purpose PNP Transistor

J1,J2,J3________3mm or 6mm Mono Jack sockets

SW1,2,3,4______SPST Toggle or Slider Switches

B1_______________9V PP3 Battery

Clip for PP3 Battery

A basic mixer suitable for mixing microphones or even effects outputs. The overall gain from input to output is one if the pot related towards the input is full up. You can make this a net gain of ten (or any other reasonable gain) by reducing the input resistor towards the second op amp. 10K in this position gives a gain of ten, or 20db. In case you are mixing effects outputs that have an output level control constructed into them, you are able to dispense using the input level controls, or make some have level controls, some not. Each channel use a potensiometer to adjust the volume level of each channel. Audio taper potensiometers are possibly much better, but linear will do the job.

For the op amps, choose a JFET input dual or singles, such as from the National Semi LF3xx series, or something such as the TL072 or TL082. This circuit operates with 9V power supply.

Download the schematic diagram Simple Mixer 4 Inputs circuit in PDF document:

Simple Mixer Circuit Diagram

1 file(s) 8.05 KB

Download Circuit Diagram

Schematic diagram:

Components list:

TR1,2 = FCS9015 ; TR3 = C1213 ; IC1,2 = 741 or TL071

This circuit need about 18 VDC power supply to work, use regulated power supply for better performance.

The kit of this circuit is available on the market, i took the picture from electronic store in my town. This circuit is absolutely works.