Amp improvements over the years

[threni]

How are amps today so much better than those of, say, the 1980s? I had a NAD 3130 in the mid/late 1980s and I liked it (apart from the fact it kept breaking!). But amps now are smaller and far better performing. What changed? Did a new amp design occur to people; standard components like capacitors/resistors, or power supplies etc just getting better? Perhaps this is a stupid question for anyone knowledgeable about hardware design, but if someone teleported a Schiit Asgard 3 back in time would people be able to figure it out? (I guess that's a pure headphone amp and not strictly comparable with an integrated designed to handle multiple inputs and speakers but hopefully you get the idea). Isn't increasing the amplitude of a signal a relatively straightforward thing to do?

 

[solderdude]

The 3130 was a crappy design. It lacked emitter resistors in the power stage.
Because of this one could get 'thermal runaway' and blow the power transistors. I had to repair a few back in the days.
The idea was that this way the power stage could deliver higher peak currents.

Circuits have changed little over time.

 

[MakeMineVinyl]

The main improvement is class "D". Overall, regular amplifier technology hasn't changed much outside of that. Some of the parts have changed in relatively minor ways (availability of ThermalTrak transistors for instance).

 

[ahofer]

I have a Bryston amp from 1988, and it sounds as good as anything else I’ve tried - which is to say, audibly transparent. Tested at 135 watts into 8 ohms (advertised at 100) and was even able to drive some pretty bitchy loads (Thiel CS 3.6).

 

[Wes]

Benchmark licenses a THX technology to reduce cross-over distortion