Amplification: what are the biggest advances of the last 40 years?

Some audiophile friends and sales people are of the opinion that "older amplifiers are outdated' and therefore cannot compete with the better new high end amps

Is it true that the best newer amps always sound better than the best older units?  

No. That depends on which new amp as opposed to which older amp. Not all new amps are better.

Does either technology, better parts, or improved circuitry and engineering make such progress inevitable?

If you get rid of 'either' in that question the answer is 'yes'.

During a recent visit at my local dealer, I inquired as to why the new amplifier we were listening to was so expensive?

@bobbydd  High end audio isn't about price, its about intention. It is true that better parts are more expensive than parts of lessor performance. Its also true that low production numbers increase price. Finally there's something called the 'Veblen Effect' where a higher price tends to convey a perception of higher quality. Usually its only a higher price though. Companies that price according to a formula tend to have less expensive product than those that price according to what the market will bear but can quite easily offer higher performance.


One of the biggest audio debates in high end since before the www is the tubes/transistors debate. The reason tubes are still around is that most transistor amps are harsh and bright (entirely due to distortion and the misunderstanding that many people have that the low distortion is 'inaudible' when its obviously not; there's been a bit of denial going on...). Class D has brought the ability to build a solid state amp that isn't harsh- thus sounds just like a good tube amp without some of the bandwidth problems that are often a problem with tubes (especially higher powered tube amps).


As a designer of high end audio power amplifiers I see this as the single biggest advance in amplifiers in the last 50 years.

From the perspective of an amplifier designer, these are the biggest improvements I've been aware of.

OTLs became a lot more reliable- as reliable as any other tube amp. OTLs offer transparency like no other tube amp.
Class D amps have been refined to the point where they are contenders. If you have one that is self-oscillating, they can have a distortion signature that lacks the brightness and harshness of regular class AB solid state amps. This means they can sound smooth like a good tube amp until you run it out of gas. I'd say that's a major break-thru.
But the ability to get rid of that solid state brightness is not limited to class D. Newer semiconductors are around now that didn't exist in the early 1980s or before, making it possible to build a class AB amp that has distortion so low that they don't sound bright. The trick in both the case of the class D and the latter amps I've mentioned here is to have feedback in excess of 35dB. This allows the amp to have consistently low distortion numbers at all frequencies rather that just at low frequencies like amps of the 70s and 80s.

So that's a big deal too.