Power amp with only MJ15003


2002-01-14 12:43 pm

Could anyone give me some pointers to buildning a 100W power amp with only MJ15003 and TIP29/30 as output transistors (ie no MJ15004's).

I have a fender guitar amp with the output stage broken. If I have to replace all of the output components I might as well build a new one, as the copper barely sticks to the board anymore.

I already have some MJ15003 and TIP 29/30 because those are the types present in the output stage.


Pick a simple, well documented, tried and tested circuit such as the ESP Project 3A ( http://sound.westhost.com/project3a.htm ). Modify the output stage from a fully complementary CFP arrangement to a quasi-complementary (darlington/CFP) by slightly re-arranging the upper half of the output stage. You will then be able to use just your MJ15003s. If you wish to try this, email me and I will send you a modified schematic.

Otherwise, there are several alternative circuits using quasi-complementary output stages that you will be able to find on the web or in other publications.