Need help in understanding how to recognise the stages and analyse a 60-100W power amplifier from sound-au
Reposting since the previous post didn't have a clear title.
I've been trying to understand this circuit for a while now, but have no idea how to connect the pieces. It's a 60-100W Power Amplifier from sound-au that I'm trying to build.
I first thought of Q1 and Q2 to be a part of a long tailed differential pair with Q3 and R7 acting as the current source, but Q1 and Q2 have asymmetrical loads in the collector, so I am again unsure if it is one or not.
Likewise, I am struggling to identify the patterns in the circuit and make an analysis of what each stage is doing.
I had the plan of trying to simulate the circuit stage by stage and then bringing it all together in LTSPICE/QSPICE, but I haven't even been able to understand the first stage.
Would really appreciate some help. Thanks!
Posted Aug 13, 2026, 4:48 PM UTC