Still one advice: please use well tested or new parts and not ( you may decite) often used parts.For resistors it’s a pre to use metalfilm. I wish you all a lot of pleasure with this old fashioned ampli witha very modern sound. If you want to try this please try to make your first one on a pice plastic and mount it point to point like the drawing. If you cann’t find the small transistors, no problem there are enough alternatives for them.Ī good heatsink does not mean a big one, but i advice to use an old fashioned one because you can it heat up firmly. Real important is a good transformer and the fuses need to be T 3,15 aĭont be shy and at least give it a try and you’ll be surprised of the sound. You realy can use almost any combination of parts in resistors, capasitors and transistors. I’ve build at least 30 of these amplifiers andthey all work still after 5 jears very well.I use them in self powered loudspeakers and as poweramplifier for small and middel events. But if this current decreases, the transistors are not heating so much, but the sound gets worse… As this current increases, the sound of the amplifier gets better, but the end transistors are more heating. This current can be regulated with the 500Ω trimmer resistor.
As you can see, in this design the components have a big tolerance, so you can build it almost of the components, which you find at home. What will be given below is a sort of 'transistor amplifier cookbook' design. There is no one amplifier design and a lot of designs will work OK. This cookbook design will work well under most situations just like a recipe usually works when you cook.
Most of the Class B distortion comes from the use of the output transistors as rectifiers to separate the plus and minus halves of the signal as well as then.
The maximal input voltage is around 0.8 – 1V. a sort of 'transistor amplifier cookbook' design. Amplifier analysis shows that a Class B amplifier has a no-feedback distortion of about 33 and a Class A amplifier has a no-feedback distortion of about 8 and sound better than Class B. The optimal supply voltage is around 50V, but this amp work from 30 to 60V.