120W MOSFET power amplifier by
300W Mosfet power amp OCL HIFI Class AB by K1530+J201
Mosfet Amplifier OTL 100W by K1058,J162
Class-A MOSFET Amplifier by 2SK1058
This is simple Class-A MOSFET Amplifier, used mosfet 2SK1058 in circuit.
It is easy to make, Must use supply volte 24V at high current. read more
Simple Class A Power Amplifier by IRF530
I was in need of high quality headphones amplifier because of many reasons and decided to build SDS Labs phone amp. This is extremely rewarding project in a sense that it is fully documented, includes PCB, parts list and building notes – so it’s easy to build and then it sounds great. I have used IRF530 and IRF9530 pairs and they work just fine given the fact that you add 100-300 Ohm gate resistors to prevent high frequency oscillations. This is a common problem for MOSFET designs and if you don’t have a good oscilloscope or want to be on the safe side just use gate resistors on any MOSFET design. Ferrite beads put over gate pin could also be used instead but I somehow prefer resistors.
Class A Power Amplifier by IRF530N+78L05
I use two 6x6x4cm heatsinks per channel. Power supply is unregulated (just transformer, diode bridge and capacitors) but I cannot hear anything even when I put my ear within few centimeters of the loudspeaker. Opamp has very good power supply rejection ratio. I’ve tried to keep everything as simple as possible and basically LM317 would be just one extra opamp… If you are looking for better sound, get separate regulated low power supply just for the U1 opamp, something like +-15V at 100-200 mA.
I have also used one LM7805 to get bias for both channels – you may want to use two separate 7805 in a final amp to get better channel separation. R2 pot is anything from 500 to 50k. I have used 22k
The Zen Headphone Amplifier by IRF610
This circuit to obtain the best sound from my Grado SR-325 headphones. Portability here was not imperative, so the high power consumption of a real class A amp was not a big drawback. I developed this project at the beginning of 2002 and it was first presented at DIYaudio.com in February 2002. Since the intellectual property belongs to Pass Labs, this circuit is intended only for notâ€“forâ€“profit use, unless the current source topology is altered.The schematic in figure 1 shows one channel of the headphone amp. The HexFets employed are the usual International Rectifier IRF610, both for the active side and for the current source. The circuit is quite simple, only one gain stage built around an IRF610 (Q2 at the bottom of the schematic), biased by another IRF610 (Q1). The two diodes (D1 and D2) are for over-voltage protection purposes: any type, between few volts and about 15-16V will work fine
Amplifier MOSFET HIFI 240W by BUZ23
Here is Circuit Power Amplifier MOSFET HIFI 240W by BUZ23
200W MOSFET Amplifier Hifi audio powerhouse
Power Amplifier MOSFET HI-FI 300W by 2SK1058, 2SJ162
The amplifier consists of two completely separate monaural amplifiers each channel has its own power supply, resulting in zero inter-channel cross talk, a common phenomenon in amplifiers sharing the same power supply. In order to obtain the full output power each supply transformer should be rated at 40VAC – 0 – 40VAC at 640VA. Unlike many designs relying on the reservoir capacitors to supply peak currents, I prefer to have the raw power available from the transformer resulting in much faster transients. Although the RAS 300 specifications are moderate, when listening to it you will immediately experience the massive reserve power available and never have any cause of anxiety that something is going to give in that one would when driving many amplifiers loud. You will hear nothing but reality with no distortion at any level and I guarantee that this amplifier will divulge the best qualities of any equipment connected to it.
Simple Audio Power Amplifier 60W by K1058, J162
Mosfet Power Amplifier 120W by K1058,J162
This amplifier evolved from the previous 6 transistor mosfet amplifier. That design was already so good there seemed no reason to look for improvements, but the high open-loop distortion at 20kHz and the resulting triangular ‘error voltage’ extracted suggested that the non-linear mosfet capacitance was responsible for almost all the distortion, and although the closed-loop distortion remains below 0.01% this could easily be reduced further by driving the mosfets from a lower impedance just by adding an emitter-follower.
Power Amplifier Mosfet OCL 70W HIFI Stereo with IRF640,IRF9640
This circuit is from David White’s article in Electronics World
(August 2001). It uses inexpensive HexFetâ„¢ Power MOSFETs as output
devices. Since their transconductance is low, the rest of the design is
geared towards producing maximum open-loop gain. Overall Negative
Feedback is used to set the gain to 27dB and to reduce the distortion.
The input devices used (2SA970) are low-noise, high gain PNP devices. They have poor Vce(max), so their supply voltage is reduced using a simple Zener diode regulator built using R3, ZD1 and C3. T1 is used as a current source. The author of the original EW article mentioned using a plain gate-source connected JFET, which is selected to produce 1mA current. At Rs. 25 a pop, I was not about to do this with BF245s. Besides, the current for my G-S connected BF245s is around 7mA. Insert a resistance in series with the source to reduce the current. Since the source-drain current is dependent on the manufacturing process, you should select the resistor for each BF245 in a multiple-amp. system. The value should be selected for 1mA current. If required, use a 1k pot here.
Power amplifier 65W with HEXFET IRF540, IRF9540
A medium power amplifier that is characterized by a lot of good sound quality, but simultaneously is very simple in the construction. Him uses, enough time in my active loudspeakers. In his output stage exist the very good FET transistors, technology HEXFET, transistor which are controlled by voltage and no by current as the classically bipolar transistors. The circuit has symmetrical designing, resolving thus the harmonic distortion problem. All the transistors that are used in the circuit are simple and they exist in big clearings in the market. The pairs of differential amplifiers Q1-2 and Q3-4 should be matched between them and near the one in the other….
R1-15-16-21-22-17-18=1Kohm R33=68ohm 5W Q1-2=BC550C [matched]
R2=47Kohm R35-36=6.8ohm 1W Q3-4=BC560C [matched]
R3-4=10Mohm TR1=1Kohm trimmer Q5=BC560C
R5-6-13-14=1.2Kohm TR2=1Mohm trimmer Q6=BC550C
R7-12=47ohm C1=2.2uF 63-100V MKT Q7-11=BD140
R8-9-10-11=22ohm C2=1nF 100V MKT Q8-9-10=BD139
R19=82ohm C3-4=2.7nF 100V MKT Q12=IRF9540
R20=22Kohm C5=330pF ceramic or mylar Q13=IRF540
R23-26=56ohm C6-7=100uF 16V F1-2=Fuse 2.5A Fast
R24=2.2Kohm C8=1uF 100V MKT L1=see text 
R25=560ohm C9-11-12=100nF 100V MKT J1= 2pin connector 2.54mm step
R27-30=150ohm C10-13=470uF 63V
R28-29-31-34=15ohm C14=33nF 100V MKT Q8-10-11-12-13 on Heatsink
R32=150ohm 5W D1-2=LED RED 3mm [see text]  All the resistors is 1/4W 1% except quote differently
Power Amplifier 45W with HEXFET IRF9540,IRF540
A ideal solution for the make a good, low cost power amplifier. It’s a ideal solution for the creation a system of home cinema. The preamplifier and the driver support in a operational amplifier [IC1]. The voltage fall in resistors R5 and TR2/R6, drive the output FET’s gates and is proportional with the input signal level. Transistors Q1-2 function as voltage stabilizers in the supply lines, but ensure also the essential voltage fall, because the IC1 it should not they are supplied with voltage bigger Â± 18V. …
R1=47Kohm C1-2-6-7=100nF 100V MKT Q5-6=IRF9540
R2-12=1Kohm C3-4=22uF 25V Q7-8=IRF540
R3-4=3.3Kohm C5=220pF styroflex TR1=5Kohm trimmer multiturn
R5=1.2Kohm C8-9=4700uF 63V TR2=1Kohm trimmer multiturn
R6=[1.2Kohm] 820ohm *See text C10=1uF 100V MKT F1-2=fuse 3A
R7=270ohm D1-2=15V 0.5W zener J1=2pin connector 2.54mm step
R8=220ohm IC1=LF411orAD711or LF351 J2=5pin connector 5mm step
R10-11=22Kohm Q2=BC560C All Resistors 1/4W 1% metal film
Basic MOSFET amplifier 100W with 2SK1530,2SJ201
I propose you here a basic MOSFET amplifier. Output power is +/- 100 Wrms under 8 ohms or +/- 160 Wrms under 4 ohms.
Due to the circuit simplicity, distortion is +/- 0.1 %. Bandwidth at -3 db is from 4 Hz to 96 Khz, it is limited by C1, R1, C2 and R2.
Transistors T1 and T2 makes a first differential stage, current source of +/- 1 mA is set by R3. In the upgraded version, current source is more efficient in stability. P1 allows a fine tuning of DC voltage at amplifier’s output. Place P1 at it’s half value for first power up, then turn it slowly for a lowest DC output voltage. Use a first quality compoment.
C1 = 2,2 µF MKP, MKT 100 V
C2 = 330 pF ceramique 50 V
C3 = 100 nF MKP, MKT 100 V
C4 = 100 µF 40 V electro-chimique
C5, C6 = 18pF ceramique 50 V
C7 = 100 nF MKP, MKT 250 V (C8 = 47µF 100 V)
R1, R3 = 47 K (R3 = 330 – 470 Ohms)
R2 = 2K2
R4, R5 = 3K9
R6 = 1 K
R7 = 27 K
R8, R9, R11 = 100 ohms
R10 = 10 K
R12, R13 = 470 ohms
R14, R15 = 0.33 ohms 5 watts
R16 = 10 ohms 3 watts (R17 = 1 K R18, R19 = 10K)
T1, T2, T9,T10 = 2N5401, ZTX558, BC556B (attention au brochage different – take care for pin layout)
T3, T4 = BF470, MJE350, 2SB649
T5, T6 = BF469, MJE340, 2SD669
T7 = IRFP240, 2SK1530, 2SJ162, BUZ900DP, BUZ901DP (attention au brochage different – take care for pin layout : GDS GSD)
T8 = IRFP9240, 2SJ201, 2SK1058, BUZ905DP, BUZ906DP (attention au brochage different – take care for pin layout : GDS GSD)
P1 = 100 ohms (25 tours – 25 turns)
P2 = 2K5 (25 tours – 25 turns)
F1, F2 = 3 A T
power amplifier OCL 180W MOSFET J50 and K135
power amplifier OCL 180W MOSFET J50 and K135
Power Amplifier OCL 100W Mosfet J162 + K1058
This is circuit MOSFET power amplifier OCL, Output 100w ,
use mosfet k134+j49 or Mosfet J162 + K1058
Output 112W at Speaker 8 OHM.
Power Supply +56V/-56V 4A /Ch.
PCB power amplifier ocl 100w Mosfet J162 + K1058
Power Amplifier OCL 50W by Mosfet (K1058 + J162)
The 50W Power Amplifier OCL Mosfet (K1058 + J162) is easy to build, and very inexpensive.
To use Power Supply +35V -35V at 2A. Power Mosfet (K1058 + J162) must be mounted on heatsink.
Can be directly connected to CD players, tuners and tape recorders.
Power Amplifier VMOS OTL 10 Watt
circuit VMOS 10 Watt Amplifier
Hello! This the circuit amplifies small-sized.it uses the equipment VMOS , number BD512 and BD522. which be pillar heart of the circuit. By it very the circuit is the character of OTL , make build easy and the price economizes. It is giving watt about 10W when , use force against 8ohm size loudspeakers and use a place turn on the power 33V sizes that the trend about 1.5A yes.