It's difficult to make head to head comparisons because the technologies used are so different. So what I'll do is draw on some of those differences and why they're important.
Take the average high-end AV receiver. There's lots happening on the digital side of things: HDMI inputs, video conversion and scaling, image processing, multiple decoding modes etc etc. Then there's the the various AtoD and DtoA conversions, some of them for video as well as audio. Consider the power too. Are there many big amps that don't boast 150+W/ch; many are 200W+. Throw in networking, App control, Airplay, 2/3/4 rooms of multi-zone, auto room EQ, multiple channels (9.1+), assignable amps, bi-amping, and now ATMOS too and you start to see just how busy the average high-end £1500-£2000 at box of tricks is.
Now look at the prices.
The DSP-A1 launched in 1998 at around £1600. Adjusted for inflation that equates to £2550 in today's money. Yet it was just a 7.1 amp, 5x110W for the main channels + 2x 35W for the effects. No video conversion, no networking, no HDMIs, no scaling, no set-up mic, no multi-room.... hell, it didn't even have a component video through-put.
15+ years is long time in the AV industry. There's a lot of new technology coming on stream so certain things get cheaper. Markets grow for products too. That helps keep production costs down thanks to volume. But still the fundamentals don't change. Raw materials, fuel and transport costs are all higher than they were in the late 90's. Take a look at 2 channel Hi-Fi amp prices. There's a lot of common components; transformers, circuit boards, capacitors, cases etc. Something like the Rega Brio amp has been around in various iterations for almost the same span of time that we are talking about. In 2001 it would have cost £298. Adjusted for inflation that would be £450 today. Yet the latest Brio R costs £549.
So, how come is it that Yamaha (or any of the big manufacturers) can take what should be a £2500 chassis, then stuff in a shed load more tech, more features, more channels, 50% more more power and yet still sell it profitably for 20% less than its older sibling when the fundamentals all point in the opposite direction? The answer is that somewhere under the skin there's more economising done than simply derives from volume manufacture in China. That's why the amps today don't sound as good.
We know from PCs how digital switching noise plays havoc with analogue circuits. We know from the performance of Hi-Fi amps versus AV amps that wattage on the specs page doesn't translate to real life power. We can tell by listening when an amp struggles to deliver the power required for big transients. The power from a big transformer only goes so far. Sustained power delivery and the ability to cater for instantaneous demand too requires big capacitors to act as a power reservoir. The more watts being claimed then the bigger and more expensive those capacitors need to be. The wattage arms race has become self defeating. In finding new ways to deliver the Marketing Department's insatiable demand for bigger spec sheet numbers on wattage, the engineers have had to cut back on the very components that guarantee the amp's performance beyond the first millisecond of peak output. They've taken out the big V8 and replaced it with a turbo charged straight 4 cylinder that only delivers peak power at mad (and unusable) revs.
