Sunday, January 16, 2011
18 Watt RMS Amplifier Using TIP41|42
This amplifier Circuit has output 18 Watt RMS into 8 Ohm and Frequency response 30Hz to 20KHz. It’s simple to build and you don’t need preamplifier. Besides that this Amplifier Circuit is also directly connected to Can some CD players, tuners and recorders tape. Do not exceed 23 + 23V supply. Of Q3 and Q4 must be mounted on heatsink. D1 must be in thermal contact with the Q1. Quiescent current (best measured with an Avo-meter in series with Q3 Emitter), is not critical. Adjust R3 to read a current Between 20 to 30 mA with no input signal.
List Component:
P1 : 2K Log. Potentiometer (Dual-gang for stereo) R1 : 1K 1/4W Resistor R2 : 4K7 1/4W Resistor R3 : 100R 1/4W Resistor R4 : 4K7 1/4W Resistor R5 : 82K 1/4W Resistor R6 : 10R 1/2W Resistor R7 : R22 4W Resistor (wirewound) R8 : 1K Trimmer Cermet (optional) C1 : 470nF Polyester Capacitor C2,C5 : 100µF/3V Tantalum bead Capacitors C3,C4 : 470µF/25V Electrolytic Capacitors C6 : 100nF Polyester Capacitor D1 : 1N4148 150mA Diode IC1 : TLE2141C Op-amp Q1 : BC182 NPN Transistor Q2 : BC212 PNP Transistor Q3 : TIP42A PNP Transistor Q4 : TIP41A NPN Transistor
IRF9530|IRF530 Simple MosFet Amplifier
This mosFet amplifier circuit was a sort of challenge: designing an audio amplifier capable of delivering a decent output power with a minimum parts count, without sacrificing quality.
The Power Amplifier section employs only three transistors and a handful of resistors and capacitors in a shunt feedback configuration but can deliver more than 18W into 8 Ohm with <0.08% THD @ 1KHz at the onset of clipping (0.04% @ 1W - 1KHz and 0.02% @ 1W - 10KHz) and up to 30W into a 4 Ohm load.
 |
| IRF9530|IRF530 Simple MosFet Amplifier Circuit |
List Component
R1 : 2K2
R2 : 27K
R3,R4 : 2K2 1/2W Trimmers Cermet or Carbon (or 2K)
R5 : 100R
R6 : 1K
R7,R8 : 330R
C1 : 22µF/25V
C2 : 47pF
C3,C4 : 100µF/50V
C5 : 2200µF/ 50V
Q1 : BC550C
Q2 : IRF530
Q3 : IRF9530
Setting up the Power Amplifier:
- Connect the Power Supply Unit (previously tested separately) to the Power Amplifier but not the Preamp: the input of the Power Amplifier must be left open.
- Rotate the cursor of R4 fully towards Q1 Collector.
- Set the cursor of R3 to about the middle of its travel.
- Connect a suitable loudspeaker or a 8 Ohm 20W resistor to the amplifier output.
- Connect a Multimeter, set to measure about 50V fsd, across the positive end of C5 and the negative ground.
- Switch on the supply and rotate R3 very slowly in order to read about 23V on the Multimeter display.
- Switch off the supply, disconnect the Multimeter and reconnect it, set to measure at least 1Amp fsd, in series to the positive supply (the possible use of a second Multimeter in this place will be very welcomed).
- Switch on the supply and rotate R4 very slowly until a reading of about 120mA is displayed.
- Check again the voltage at the positive end of C5 and readjust R3 if necessary.
- If R3 was readjusted, R4 will surely require some readjustment.
- Wait about 15 minutes, watch if the current is varying and readjust if necessary.
- Please note that R3 and R4 are very sensitive: very small movements will cause rather high voltage or current variations, so be careful.
- Those lucky enough to reach an oscilloscope and a 1KHz sine wave generator, can drive the amplifier to the maximum output power and adjust R3 in order to obtain a symmetrical clipping of the sine wave displayed.
Circuit From: www.redcircuits.com
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/
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 |
- 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
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
Subscribe to:
Posts (Atom)