Comments on: 150 Watt amplifier circuit

By: admin

admin — Sat, 27 Feb 2010 08:00:40 +0000

Reply to Anthony Deane
All transistors are correct. I think there is no problem with the circuit. Pls check your circuit and components.

Many guys have successfully assembled this circuit .

By: Anthony Deane

Anthony Deane — Fri, 26 Feb 2010 23:07:30 +0000

Dear Sir,
I have change the 2N3903 transistors to BC557 and is still having problem to get the output signal to the speaker.
Are these the correct transistors TIP 142, 147 and 41 and is this the correct voltage to feed the circuit 45v 5A.
All the other components used are rated according to the diagram posted on this site. I don’t want to give up at this time please help me.
I am looking forward for you urgent respond and any members who have completed this project and got through please assist me.You can contact me on my email at ajdeane03@yahoo.com
Best Wishes
Anthony

By: admin

admin — Thu, 25 Feb 2010 11:33:26 +0000

Reply to Anthony

2N3903 is NPN and it is not a replacement for BC558 which is a PNP transistor.That’s the problem.

2N2907, BC158, BC557, BC177 etc are the suggested replacements for BC558

By: Anthony Deane

Anthony Deane — Tue, 23 Feb 2010 19:13:23 +0000

Dear Sir,
I have reciently build this 150w amp, all the components used on the circuit are of the correct values, except for the Bc558 transistor. I was given the replacement value which is 2N3903 transistors.I connect them according to the diagram you post but when I powered this amp I am not getting an output signal to the speaker. When I test the circuit the power is going to the 1st transistor. What diganosis can you give me to solve this problem, please email me at ajdeane03@yahoo.com thanks.

By: Seetharaman

Seetharaman — Wed, 17 Feb 2010 04:41:25 +0000

Dear Manoj you can built any preamplifier using both positive and negative power supply if it is to be built in as the output amplier is with dual supply. For externally powered pre amplifier I have tried with Two transistor tone controller circuit appeared in these column and found to be sounding perfectly alright. Kindly inform what are the inputs you wand to handle. happy listening.

By: Seetharaman

Seetharaman — Wed, 17 Feb 2010 04:26:45 +0000

Hi Nr Gregtherider Yes with one end of the transformer connected to center of two filter capacitors connected in series. other end of the transformer to anode of the first rectifier and also to cathode of second rectifier. cathode of first rectifier to positive end of serially connected filter capacitor and anode of the second rectifier to negative of serially connected filter capacitor. serially connected Capacitors center is taken as zero volt. Only problem is i have to use double the value for the filter capacitor to reduce the ripple and hum. I have used 2 X 4700MFD 63Volt each for both positive and negative supply.
kindly send your email id to seethasub@hotmail.com for detailed circuits

By: gregtherider

gregtherider — Sun, 14 Feb 2010 20:31:14 +0000

@ SEETHARAMAN: Can you please tell me how did you make +-30V from 30V transformer? Voltage doubler? Some schematics would be very helpful!

By: Manoj

Manoj — Sun, 14 Feb 2010 10:30:50 +0000

Hey
I really liked the circuit seems pretty good. I wanted to build this aong with an uA741 preamp circuit i was wonderin if tht is good or do u have better pre amp circuits in mind?

By: cled..from philippines

cled..from philippines — Fri, 05 Feb 2010 02:40:05 +0000

regards 2 Ryan….gudluck 2 your circuit project!!!!

By: cled..from philippines

cled..from philippines — Fri, 05 Feb 2010 02:31:44 +0000

u can e mail me at cled_alagban2000@yahoo.com hello 2 all cicuit fanatics!!!dis web is very helpfull…