Sunday, January 16, 2011

70 Watt Guitar Amplifier Using 2N30055/MJ2955 Transistor

The Guitar power amplifier circuit of this design adopts the still new but already successful 45 Watt Class B Amplifier Simplicity and ease of construction of this amplifier, combined with the complete absence of manual settings make it ideal for Guitar or Bass amplifier.
70 Watt Guitar Amplifier Circuit

Preamplifier + Tone Control  For Guitar Amplifier Circui

The preamplifier features two almost identical three-transistor gain-blocks based on a complementary two-stage circuit with dynamic active load of the output transistor. A circuit topology early used in Revox tape recorders and audio preamplifiers with single rail supplies in the 18 - 24Vdc range.

In this preamp the gain blocks are powered by split supplies of ±24V with two advantages: a high output voltage of about 15V RMS allowing a very wide overload margin and the facility to easily derive the preamp power supply from the power amplifier main supply.

A three-band stacked-type tone control is implemented in the second stage but, unlike the more common passive controls, active controls are used here, allowing better signal to noise ratio and overload margin with no gain loss.

List Componet Of  Guitar Amplifier
R1             : 8K
R2             : 3K9
R3,R6          : 1K 
R4             : 2K2
R5             : 15K
R7             : 22K
R8             : 330R
R9,R10         : 10R
R11,R12        : 47R
R13            : 10R

C1             : 1µF/63V 
C2             : 470pF/63V 
C3             : 47µF/25V 
C4             : 15pF/63V 
C5             : 220nF/100V
C6             : 100nF/63V
D1,D2,D3,D4    : 1N4148  150mA Diodes

Q1,Q2          : BC560C  PNP Transistors
Q3             : Q4BC556 PNP Transistors
Q5             : BC546   NPN Transistor
Q6             : BD139   NPN Transistor
Q7             : BD140   PNP Transistor
Q8             : MJ2955  PNP Transistor
Q9             : 2N3055  NPN Transistor

List Componet Of  Preamplifier
P1             : 10K  Potentiometer
P2,P3,P4       : 47K  Potentiometers
P5             : 10K  Potentiometer

R1,R2          : 33K  
R3             : 220K 
R4             : 390R 
R5,R14         : 3K9 
R6,R15         : 8K2 
R7,R16         : 12K 
R8,R11,R17,R20 : 560R  
R9,R18         : 5K6 
R10,R19        : 100R  
R12            : 3K3 
R13            : 18K 
C1,C12         : 220nF Polyester Capacitors
C2,C13         : 100pF Ceramic Capacitors
C3,C14         : 10pF  Ceramic Capacitors
C4,C15         : 47µF/25V Electrolytic Capacitors
C5,C16         : 100µF/25V Electrolytic Capacitors
C6,C7          : 10µF/25V Electrolytic Capacitors
C8,C11         : 4n7  Polyester Capacitors
C9             : 10nF Polyester Capacitor
C10            : 47nF Polyester Capacitor

Q1             : BC560C  PNP Transistor
Q2,Q3,Q5,Q6    : BC546   NPN Transistors
Q4             : BC557   PNP Transistor 
 
Circuit From: http://www.redcircuits.com/ 
[read here...]

Thursday, January 13, 2011

18W Guitar Amplifier Using Darlington Transistor

The aim of this design is to reproduce a Combo amplifier of the type very common in the 'sixties and the 'seventies of the past century. It is well suited as a guitar amplifier but it will do a good job with any kind of electronic musical instrument or microphone. 5W power output was a common feature of these widespread devices due to the general adoption of a class A single-tube output stage (see the Vox AC-4 model). Furthermore, nowadays we can do without the old-fashioned Vib-Trem feature frequently included in those designs. The present circuit can deliver 10W of output power when driving an 8 Ohm load, or about 18W @ 4 Ohm. It also features a two-FET preamplifier, two inputs with different sensitivity, a treble-cut control and an optional switch allowing overdrive or powerful treble-enhancement. 

18W Guitar Amplifier Using Darlington Transistor Circuit
Note:
  • SW1 and related capacitors C4 & C5 are optional.
  • When SW1 slider is connected to C5 the overdrive feature is enabled.
  • When SW1 slider is connected to C4 the treble-enhancer is enabled.
  • C4 value can be varied from 100nF to 470nF to suit your treble-enhancement needs.
  • To set quiescent current, remove temporarily the Fuse F1 and insert the probes of an Avo-meter in the two leads of the fuse holder.
  • Set the volume control to the minimum and Trimmer R9 to its minimum resistance.
  • Power-on the circuit and adjust R9 to read a current drawing of about 25 to 30mA.
  • Wait about 15 minutes, watch if the current is varying and readjust if necessary.

List Component:
P1           : 4K7  Linear Potentiometer
P2 : 10K Log. Potentiometer
R1,R2 : 68K 1/4W Resistors
R3 : 220K 1/4W Resistor
R4,R6,R11 : 4K7 1/4W Resistors
R5 : 27K 1/4W Resistor
R7 : 1K 1/4W Resistor
R8 : 3K3 1/2W Resistor
R9 : 2K 1/2W Trimmer Cermet
R10 : 470R 1/4W Resistor
R12 : 1K5 1/4W Resistor
R13 : 470K 1/4W Resistor
R14 : 33K 1/4W Resistor
C1 : 100pF Ceramic Capacitor
C2 : 100nF Polyester Capacitor
C3 : 470µF Electrolytic Capacitor
C4 : 220nF Polyester Capacitor (Optional, see Notes)
C5 : 47µF/25V Electrolytic Capacitor (Optional, see Notes)
C6 : 1µF/63V Polyester Capacitor
C7,C8,C9,C10 : 47µF/25V Electrolytic Capacitors
C11 : 47pF/63V Ceramic Capacitor
C12 : 1000µF/35V Electrolytic Capacitor
C13 : 2200µF/35V Electrolytic Capacitor
D1 : 5mm. Red LED
D2,D3 : 1N4004/400V 1A Diodes
Q1,Q2 : 2N3819 General-purpose N-Channel FETs
Q3 : BC182 NPN Transistor
Q4 : BD135 NPN Transistor (See Notes)
Q5 : BDX53A NPN Darlington Transistor
Q6 : BDX54A PNP Darlington Transistor
SW1 : pole 3 ways rotary switch 
SW2          : SPST Mains switch
F1 : 1.6A Fuse with socket
T1 : 220V Primary, 48V Center-tapped Secondary 20 to 30VA Mains transformer
[read here...]

Wednesday, January 12, 2011

Simple FET Audio Mixer

This simple circuit mixes two or more channels into one channel (eg. stereo into mono). The circuit can mix as many or as few channels as you like and consumes very little power. The mixer is shown with two inputs, but you can add as many as you want by just duplicating the "sections" which are clearly visible on the schematic.

Simple  FET  Audio Mixer

Note:
  • As many or as few channels as are required can be added to the mixer. Do this by just duplicating the input "sections" which are clearly shown on the schematic. One version of this mixer I saw had 25 inputs!
  • A shielded case is probably needed to reduce hum and help stop oscillations.
  • The circuit can be powered by a single 9 volt battery.

List Component
R1, R3     : 10K Pot
R2, R4 : 100K 1/4 W Resistor
R5 : 6.8K 1/4 W Resistor
C1, C2, C3 : 0.1uF Capacitor
Q1 : 2N3819 Junction FET
[read here...]

Wednesday, November 24, 2010

200 WATT AUDIO AMPLIFIER

Output Power : 200Watts
Load Resistance : 8ohms
Input impedance : 55K
Maximum supply voltage : (+95v)-0-(-95v)
Recommended supply voltage : (+66v)-0-(-66v)

This complete high quality, low noise mono audio power amplifier is based around the Hybrid Integrated Circuit STK4050 manufactured by Sanyo. The circuit incorporates volume and has a maximum music output power of 200W. The circuit incorporates an on board power supply; therefore, only centre tapped transformer is required to power the circuit. I t has very good quality sound. U can use it with your Home Theatre your PC & etc... You can also use it as Subwoofer Amplifier. It is a compact package for THIN-TYPE Audio sets. Easy Heat sink design to disperse heat generated in THIN-TYPE audio sets. Constant-Current circuit to Reduce supply switch-ON and switch-OFF shock noise. External supply switch-On and switch-OFF shock noise muting, Load short-circuit protection, thermal shutdown and other circuits can be tailored-designed.
[read here...]

Thursday, September 9, 2010

FM Transmitter 4Watt


TECHNICAL CHARACTERISTICS:
Stabilised tendency of catering: Vcc=12~16V
Frequency of emission: 88~108MHz
Consumption: 100~400mA
Circuit diagram:

Materially:
The resistors are 1/4W.
R1, R2 10KOhm
R3 47Ohm
C1, C2 1nF
C3 4,7uF/16V
C4, C7, C8 0~45pF trimmer
C5, C6 10pF
C9 100nF
L1 4 turns, 7mm diameter *
L3 3 turns, 7mm diameter *
L4 5 turns, 7mm diameter *
L2 RFC (resistance 1MOhm with wrapped around her inductor of enough coils from fine isolated wire. Scratch of utmost inductor and you stick in utmost the resistance making thus a parallel L-r circuit.)
T1, T2 2N2219
ANT Simple dipole l/2.
MIC IN Microphone dynamic or other type. (It can also connected to a cassette player unit)
* The inductors is air from wire of coaxial 75W or other 1mm roughly.
PCB:
Before you print it out with microsoft paints, set the screen resolution to 1280 by 1024 in order to get the correct scale

Regulations:
With the C4 we regulate the frequency.
With their C7, C8 we adapt the resistance of aerial (practically to them we regulate so that it is heard our voice in the radio as long as you become cleaner).
Notes:
The T2 wants refrigerator.
[read here...]