Solid State Single-Ended Amplifier

[radu2326]

Good day to all of you people ! Today I decided to post my succes in creating a High-Fidelity amplifier that some of you will find verry interesting. The schematic is tested and made fully working. The output transformers are some 125 Watt 230 Volt to 32 Volt and work amazing, I have special transformers but I like this more.

 

[mr_zener]

Interesting design, can you tell be more about the output transformers?
Seems with that turn ratio and rail voltage you wouldn't get much output swing.

 

[radu2326]

The output transformers are from a class AB amplifier that had one for each channel, they have 230 VAC primary and 2 x 32 VAC secondary with a center tap. I like a ratio around of 10 to 1 because the bass sounds good, if I try the ratio of 5 to 1 the emitter resistor is to big to push the transformer, at this moment I have 56 Ohm resistor equivalent for the emitter and these transformers have a DC resistance of 22 Ohms. I am planning to try a Puss-Pull because I have all the parts.

 

[bogdan_borko]

You need an output transformer with a gap for single ended amplifier... And what is the output power with just 40mA idle current?

 

[radu2326]

At 60 Volts peak to peak on primary it would start to clip or 7 Volts peak to peak on secondary. The power darlington transistor can use almost all the voltage for amplifying.

 

[radu2326]

If someone will try to build it, this is the right version for 85 VDC like I have it on my table. The power darlington NPN transistor is 2SD1314 and the biasing PNP is 2SA1009. I am open for further questions and I will try to answer how I can.