Geez i fell like a detective, and with that data inspector Clouseau to be specific.....

per the threshold - complete the math!! 100mV across what? What's the derived current (which is what matters)? Across the emitter resistors, which are what value? Without that you don't know the current. Let's assume 1 ohm. We shall assume per device, but number of parallel devices unspecified. If nelson claimed it was A to 50 watts, that's 20V/8ohms or 2.5A; which implies 25 parallel NPN and 25 more parallel PNPs per channel -- minimum. Some number there does not add up.

per the threshold - complete the math!! 100mV across what? What's the derived current (which is what matters)? Across the emitter resistors, which are what value? Without that you don't know the current. Let's assume 1 ohm. We shall assume per device, but number of parallel devices unspecified. If nelson claimed it was A to 50 watts, that's 20V/8ohms or 2.5A; which implies 25 parallel NPN and 25 more parallel PNPs per channel -- minimum. Some number there does not add up.