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

+1 @atmasphere 
The greatest innovation in amplifier technology is the fairly recent leap in Class D development that made them as smooth as tube amps.

I would say that the improvements in manufacturing processes for semiconductors makes it much easier today to develop great amplifiers. Regardless if it is a Class A, Class AB or Class D amplifier.

Several advanced spice simulation tools now are available for free. This together with low cost high performance PCs makes it possible to perform simulations on amplifier circuits by anyone who want to learn this. Even if simulations do not tell the whole truth, it is a powerful tool when developing innovative amplifier solutions. I use such tools extensively when developing new type of amplifier solutions.

Advanced audio measurement software using relatively low cost hardware is now available. This makes it easier for startups to develop great amplifiers.

Internet makes it possible for anyone to access research articles and exchange knowledge and ideas with others. The more knowledge we put into amplifier designs the better they will get.

Hello,

Nowaday, it is not politically correct to claim that audio amp have improve within the last 40 years...

The designer in the past were not only  technician but also musician or audiophile...all were music lover.and pioner ...Franck mc intosh, Tom collangello/Mark levinson,Nelson Pass,Saul b Marantz, lew johnson et bill conrad....exct..
A circuit have to sound according to their wishes...
  There are improvements in components ,resistors,capacitor and we lost know how in tube technology since production has been given up in general, every specialist agree in this point..

To summerize,numeric technology interface is improving but not analogic amp, D class amplifier is a confortable approach to reduce volume space
In a given power output..

To date, most fameous brand name are " marketing company"and listening amp results have to respect a sound aesthetic focusing more detailled ,definition and brillance vs dynamic ,matters and Pratt ( peace ,rythm and timing)of vintage amp

So it is  just an opinion of " vintage audiophile


Raymond

My thread “Is there a SS amp that can satisfy a SET guy?”.
Today, the answer is yes… the best of Class D.
And, IME, the question can be expanded to include all tube amps and all non class d SS amps.
And speaking of “the best” class d, I anxiously await the new Atma-Sphere Class D!

Price

Class D for sure. I use avant garde class D in both my systems but I confess to tempering both with tube preamps.

sound

Better parts. Especially power supplies, volume controls. Better caps, resistors, boards. Better chassis construction and connectors. I think that consistency has also had an affect,

Better parts. Especially power supplies, volume controls. Better caps, resistors, boards. Better chassis construction and connectors. I think that consistency has also had an affect,

Class D is probably the biggest innovation.

They are close but still does not surpass the best of linear Class-A or A/B designs YET!
I DID SAY YET!!! (before you Class-D junkie’s get your knickers in a knot)

That will come maybe after they take to what Technics did, 3 x higher switching frequency 1.5mhz with the SE-R1 (my last post), one of two of Class-D’s Achilles Heels, too low a "switching frequency" and subsequent low order "output filtering" to get rid of it.
Which still leaves large remnants of it (photo) in the upper mid//high frequency audio band when using around 600-700khz switching frequency as most do today.

The other Achilles Heel is current delivery into very low bass impedances of today many top very hard to drive speakers (which the "better" linear Class-A A/B amps do standing on their heads).
To be able to "almost keep doubling it’s wattage" from 8ohm to 4ohm to 2ohm with independent testing, they never give the 2ohm wattage of class-D when comparing the 8 then 4ohm

Cheers George

Amplification is a solved problem.   Class D is probably the biggest innovation.  These days, just buy the amp you like the looks of that you can afford and you will be fine.   The biggest innovation in audiophile world has been the amazing ability to cram dollars into amplifier designs.

 biggest improvement is the GaN transistor and the new amps implementing them.

Only if used to it's fullest, as Technics did in their SE-R1 (maybe in their new SU-R100) with 3 x higher switching frequency (1.5mhz) and 3 x higher output filter for it, so this sort of 10khz square wave oscillation (upper shot) doesn't come of the speaker outputs (gets reduced by 3 x).
Lower shot has Stereophile special external test gear filtering, so it doesn't look bad for the magazine shots to the public.
https://ibb.co/N2HBQH4

Cheers George

No Class D. Overrated crap. Give me some Class A. Plinius, Pass, gets the job done. 

I think that other than refinements in circuits the biggest improvement is the GaN transistor and the new amps implementing them.

@imhififan : Especially Nelson Pass once said personally…that it’s actually the market itself that „requires“ some so called updates in his amps. He said that when asked why there is technically no difference between his X600 monos and the successor X600.5‘s …apart from a slightly different front plate. He said it winkingly … as he actually nailed the design of his monos already with the X600! The rest you can call MARKETING ;)

The Eigentakt modules, the Bryston Salomie circuit, subwoofer amplifiers and speakers with built-in amps with complex DSP room correction. 

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

An Onkyo Grand Integra M-510 (1984-1992) will cost about $13k today’s dollars.

https://audio-database.com/ONKYO/amp/m-510-e.html

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

Compare within the same brand/line, YES!
For example:
Pass Labs XA100 > XA100.5 > XA 100.8
Accuphase E-530 > E-560 > E-600 > E-650

"always" I can’t say...

Ralph is right, of course. The general trend is up. A rising tide lifts all boats. The ones that float, that is. Never forget that one little detail. Makes all the difference in the world.

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'.

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".

Personally, I'm skeptical of such statements, hence my original post.

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

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

I have not personally compared many units of different vintages in my system to answer that question.  Maybe some here have?

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.

The biggest advantage to better components in the last forty years was the advent of the compact disc and the dvd and blue ray which caused the amplifier to put out more power and dynamics to meet the demands for the new mediums. The other key components have all taken a step back in technology and sound since the start of the ipod era because of the advent of computer style electronics instead of audio grade eletronics. As for speakers they have all taken a backwards turn since 1965.

@bobbydd

The reply was something to the effect that "well, the technology and parts quality of these newer generation " units are far beyond what was possible a few decades ago. Also, that circuit design has advanced tremendously as a function of technology.

This is a valid statement. Although it’s not a stark change like the discovery of semiconductor chips, high-end audio is uses both technology and art. In our small niche high-end audio market, intense competition leads to increasing better sonic designs over time. Take prolific amplifier designer Nelson Pass for instance- his decades of designing experience has influenced his current offerings. Also, the quality of audio transformers have made significant sonic improvements.

Even internal parts can be very expensive such a Takman, Vishay, Mundoff, to name a few. Custom transformers can also be pricey. 
Also with better audio component designs (like speakers), we are better able to hear differences in the quality of amplifiers. 

That’s why we pay (and sometimes pay n pay n pay…) for these sonic improvements.

And please, none of the banal "it all matters" comments

The entire audio chain matters, but one’s system must be resolving and transparent enough to hear the differences such as to the “fool you it’s real” level. While one can throw in a quality amp and gain sonic improvement, if the rest of the system is not to the same quality level as the new amp then the rest of the system is holding back what the amp is capable of performing.

@bobbydd  

I inquired as to why the new amplifier we were listening to was so expensive?

The parts and labor that go into a quality point-to-point constructed amp are incomparably expensive vs 60 years ago.  Mass produced, PCB-based HT receivers can be churned out much less expensively (relative to inflation) than products even in the 70s.

bobbydd (OP) later said:

I inquired as to why the new amplifier we were listening to was so expensive?

Ok, so that's a different question than the original (after all, computer technology has improved massively but home computers aren't more expensive). I'd put the price change down to economics:

First, a larger number of people can afford to spend more. This comes from rising middle classes in traditionally emerging economies  (so there are just many more people who can spend money on luxuries). It also comes from increased concentration of wealth -- rather than having 100 people who can buy 100 nice-but-basic systems, there's one person who can spend lots on a single expensive system.

Second, the production of stereo gear is generally slow (low supply) so it's in the company's best interest to set high prices.

I'd also guess that better information (the internet) leads more people to chase fewer brands that are considered to be the best, further concentrating demand for (and therefore pricing power in) a few ultra-premium brands.

This has been going on for a while in French wines, and I suspect many other luxury products.  I'd say these economic forces contribute much more to rising audio gear prices than any of the component or design changes.

Getting the neurotically obsessed to believe that five-figure amps are somehow sonically superior to well-designed four-figure amps!

I am pleased with all my incarnations of my Bryston amps up top the present 7b3 (I have tried other makes btw). It is much a question of what you like ..
When I put in, now and then, my now ancient Threshold s1000's I still go "Wow - I love these"
What is better?
All depends as usual

One reason I'm asking:

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

The reply was something to the effect that "well, the technology and parts quality of these newer generation " units are far beyond what was possible a few decades ago.  Also, that circuit design has advanced tremendously as a function of technology.

So I'm wondering how much any of these explanations are valid?

Competition is the reason for the SQ we are getting today from amps. Also the number of world class speakers available at almost all price points can reveal a great amp from a good amp.

It would be helpful if people could list examples of the amplifiers with the features they think are such good improvements

Also a lot of the better solid state amps are designed with no inverse feedback that makes a big difference as well that's why I love Sim audio so much very analog sounding amp.

Better parts lead to better circuit designs.
For example, output relay replaced by mosfet in Accuphase power amp to improve DF and protection.

https://www.accuphase.com/technical_information/e-650_technical_information.pdf

Also, you can’t build a benchmark AHB2 power amplifier with parts that available 40 years ago.

https://benchmarkmedia.com/collections/all-products/products/benchmark-ahb2-power-amplifier

For me , class D :is very detailfull, open, but ,it’s emotionless.  With class A amplifiers (tubes) ,you empathize with the music !! Very good placement, 3D. You become much more involved in the music and make it much more pleasant to listen to! Give me : VAC, DartZeel, Ear Yoshino, Nagra……that makes me happy !!!

automating and serial production. faster pace lower qual.

automating and serial production. faster pace lower qual.

class D

Active speakers are a good example of how Class D enables things not possible before.  My little but over performing  Vanatoo active speakers are biamped with two Class D amps in each. 

Hands down and far and away the biggest advance in amplification in recent years has been the development of the built-in and custom designed amplification found in high-end mastering studio quality active speakers. There’s still plenty of people who seem to find much pleasure endlessly tweaking, swapping around, ruminating about, and spending inordinate amounts of money on old-fashioned external amps, interconnects, and passive speakers. Enjoy away. But overall and dollar for dollar, the latest top-quality active speakers with line-level crossovers and amps designed specifically and precisely for each *driver* in the speaker very often perform startlingly better than old-fashioned separates. The actual technical details of well-designed internal amplification for active speakers is largely irrelevant.

There’s better circuitry inside the big fat power cords. This allows for a fatter timbre and deeper colors when you see the musicians on stage

HybridDigital Purifi Eigentakt™ amplification and the integration into the NAD M33, no doubt coming to other amps soon, too.  Distortion level of 0.002%.

Biggest advance is definitely the price tag.

MOSFETs

bobbydd

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

For me I found the biggest advances for musicality/listenability came with giving "global feedback" the big flick.✔
And that came with solid state amps that use highly biased Class-a (for sweetness) but with Bi-Polar (BJT) complimentary (npn/pnp) push pull output stages, but being used without musicality killing "global feedback" surrounding them, instead using a small amount of "local feedback" only around the front amplification stage.

But to do this is properly those complimentary bi-polar output transistors that are to be used without "global feedback" have to be hfe matched, and also their emitter resistors, otherwise instability can occur.
Then you have an amp with an "iron fist" especially into low impedances, yet with the real "speaker disappearing", musicality imagining and depth act.

Cheers George

I don’t think we can argue ANY technology improved or changed as much as Class D has over this period of time. As some one fortunate to hear early Class D prototypes, to owning ICEpower amps, this technology has really come up.

Some Class D amps beat some class A amps and are beaten by some linear amps, kind of like rock-paper-scissors.  To be in the game the way they are, with huge benefits in size and efficiency to me crowns them as the single biggest innovation in this time period. 

More efficient amplifiers ie Class D and similar. Also the ability to control noise with same. That’s the big one by a huge margin that makes things possible that were not prior including beefier amps in a smaller more cost effective  package. Integrated amp technology benefits as well.

Is it that circuit design has advanced so much? Or is the bigger difference parts quality and the technology leading to these better parts?

And please, none of the banal "it all matters" comments. What I'm asking: which of the above matters the most?

Please people, read the OP. Thank you.

Better understanding of the need for good power supplies and the application thereof. Also, good transformers have become more commonly available, if not used more.

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.

There are better parts and a lot more of them on the Boutique side.

Class D amps.

The greater usage of BIG valves. The 300b is being used everywhere.

A lot of development in bigger power valves, KT90-170.

AND top Top TOP of the line amps. Valve and SS amps are just art work inside, a lot craftsmanship..

Sure are more than a few I'd like to test drive if nothing else..

Yup thing have change. I think for better and a LOT of them run a lot cooler, valve amps like the Crimson 275 and all Class ds.

Regards

So there are no great advances in sound quality, but instead as usual they figured out how to do everything just a little bit better. But that is banal, and so must not be mentioned. We will now proceed at Ludicrous Speed to list all the other stuff that we are allowed to talk about.