Analyse this amplifier for me please :)

[jim hardy]

I would test trasient response with a square-wave drive to look at the leading & lagging edges.

i would make that test using for load a speaker in its enclosure, not just a 6 or 8 ohm load resistor.http://www.edn.com/design/consumer/...periority-of-current-drive-over-voltage-drive

 

[meBigGuy]

Am I completely out of whack here? Is it a class B or a class AB?

 

[jim hardy]

Am I completely out of whack here? Is it a class B or a class AB?

Quiescent readings across the 0.33 ohm resistors would say which it is at the moment.
I suspect that'll change with temperature, especially if driver and output transistors aren't real close together on the heatsink.

 

[Gingerbunny82]

Quiescent readings across the 0.33 ohm resistors would say which it is at the moment.
I suspect that'll change with temperature, especially if driver and output transistors aren't real close together on the heatsink.

- I'm thinking it primarily operates in Class-B to be honest, the driver transistors aren't mounted on the same heatsink as the output transistors, so the output transistors get hot whilst the drivers barely get above ambient. :P

- I took a look at the output waveform on an oscilloscope, I can see a slight line in the waveform near the crossover point, very small though.

- The negative feedback must be the main reason it sounds acceptable, because if I remove any form of feedback the sound is horrific.

- It's good enough for my application though and the low quiescent power consumption of 2.5W for a stereo board is a bonus :P

I think If I was to design it again the first thing I'd do would be to replace the darlingtons with regular transistors, giving me more control over the design :)