modified 10 years ago

Single Ended Class A FET amp

01:26:39

This is the very common Mark Houston circuit on the net  a supposedly 5w output using a 2SK1058 (Spice parameters correct). But it is nowhere near 5w, in fact it has gain reduction (but works). The 15 ohm resistor handles all the current taken by the FET so it needs to be 20w. I am putting CD Player voltage at the input but the output would not reach 5watts even if you put 10v signal in the input. Something is wrong - People have built this circuit and found the output to be OK.
I'm confused? The peak output could be as much as 4.5w because of the voltage swing but on the simulator it is not even 0.5 w.

published 10 years ago

hurz

10 years ago

Max theoretical Vpp at load is supply voltage/2 = 12V. This is symetrical peak at load 6V max. U^2/R = 4.5Wpeak and 2.25Wrms @8Ohm load!! Not more and not talking about THD ;P

add comment in editor

EveryCircuit is an easy to use, highly interactive circuit simulator and schematic capture tool. Real-time circuit simulation, interactivity, and dynamic visualization make it a must have application for professionals and academia. EveryCircuit user community has collaboratively created the largest searchable library of circuit designs. EveryCircuit app runs online in popular browsers and on mobile phones and tablets, enabling you to capture design ideas and learn electronics on the go.