Remember that 25W Class A amp in a Vidar chassis I mentioned in a previous chapter? Yeah, we’re playing with that. Take the Lyr 3’s Continuity™ constant-transconductance output stage, scale it up, bias it wayyyy up, and you might have a pretty neat product, right?
Well, except for one thing. It’d really be more like a 20W Class A amp, or else it gets too hot. How excited would you be about a 20W Class A amp?
Wait. Before you answer, let’s break that down:
- 20W real honest Class A per channel into 8 ohms
- 40W into 4 ohms, falling out* of Class A
- 80W mono into 8 ohms, again falling out* of Class A
*Rather than “falling out of Class A,” a better term may be “transitioning to the Continuity™ constant-transconductance region.” This is, after all, the whole point of the Continuity output stage—it seeks to keep the output stage operating in the gm-doubled region, even when out of Class A. Is it perfect? No, of course not. But it blurs the line between Class A and Class-AB amps, at least in my opinion.**
**Of course, many people think I am crazy. Or incompetent.
Still, that’s a big, hot, heavy 20W amp. Think 50 degrees C heatsink temperatures in a 20 degree C room. And it’s only 20 watts.