Amps make no sense

[vasubandu]

I am trying to understand (a) why good amps are so expensive, and (b) why it is so hard to generate more power. In the age of digital amps, we should be talking about chips and processing.  The price of both is falling everywhere else but here.  Why?  It almost seems like a conspiracy.  What makes amps so dang expensive?

[Schu]

Remember... "good" amplifiers loose value on the secondary market making them more affordable.

Good amps are usually made with better components tighter specifications that compound the cost of a new unit.  

Better units also suffer from lack of "economies of scale" that would help to spread the investment over a larger area. They are usually made in much smaller quantities.

[DizRotus]

Class D amps offer low distortion and high power at minimal expense.

 

My excellent Texas Instruments class D TPA3255EVM (the board in the lower left of the photo) cost less than $100.  Yes it requires DIY, and I will ultimately spend three times that to put it in a proper case, but it rivals amps costing 10 times as much, or more.

 

If interested, read about class D amps in the thread below.

 

 

[jjptkd]

Sunfire amplifiers sound very good with Klipsch speakers and there's a couple for sale locally; a 405x5 Signature model which is one of my personal favorites and the lesser, more common model the original Cinema Grand at 200x5:

 

https://seattle.craigslist.org/est/ele/d/sunfire-cinema-grand-amplifier/6455326627.html

 

I'd try and get the 405x5 for around $1000, offer $900 to start, it is in very nice condition so maybe negotiate up to $1150?

 

https://seattle.craigslist.org/est/ele/d/sunfire-cinema-grand-power/6456783137.html

 

I'd try and get this one for around $600 but probably worth up to his asking price. 

 

These are older amps but made right here in Snohomish WA and Bill Flannery in Lake Stevens services them to better than new specs for very reasonable prices. 

 

http://www.flannerysvintageaudio.com/

 

 

[Chris A]

2 hours ago, vasubandu said:

I am trying to understand (a) why good amps are so expensive, and (b) why it is so hard to generate more power. In the age of digital amps, we should be talking about chips and processing.  The price of both is falling everywhere else but here.  Why?  It almost seems like a conspiracy.  What makes amps so dang expensive?

 

Neil's response partially answers the question:

 

31 minutes ago, DizRotus said:

My excellent Texas Instruments class D TPA3255EVM (the board in the lower left of the photo)!cost less than $100.  Yes it requires DIY to put it in a case, and it will ultimately cost three times that to put it in a proper case, but it rivals amps costing 10 times as much, or more.

So if you can find one instance where expensive amplifiers don't make a "dime's worth of difference", or that you can't identify which amplifier is which, then you've basically answered your question.

 

One thing that I believe you haven't asked about is this: given that there are inexpensive amplifiers that sound essentially the same as very expensive ones (i.e, the same test that Bob Carver was challenged to in the mid-1980s by Stereophile...and he won the contest), why do some inexpensive amplifiers sound bad, but others sound good? 

• Could it be the loudspeakers? (Yes.) 
• Could it be the room acoustics? (Yes, but probably this is wrapped up with the loudspeakers and their placement in-room, too.)
• Could it be that amplifier designers haven't known how to design amplifiers that sound good, because they didn't understand how the human hearing system perceives good sound reproduction? (Yes.)

Chris

[Travis In Austin]

7 minutes ago, Chris A said:

 

Neil's response partially answers the question:

 

So if you can find one instance where expensive amplifiers don't make a "dime's worth of difference", or that you can't identify which amplifier is which, then you've basically answered your question.

 

One thing that I believe you haven't asked about is this: given that there are inexpensive amplifiers that sound essentially the same as very expensive ones (i.e, the same test that Bob Carver was challenged to in the mid-1980s by Stereophile...and he won the contest), why do some inexpensive amplifiers sound bad, but others sound good? 

• Could it be the loudspeakers? (Yes.) 
• Could it be the room acoustics? (Yes, but probably this is wrapped up with the loudspeakers and their placement in-room, too.)
• Could it be that amplifier designers haven't known how to design amplifiers that sound good, because they didn't understand how the human hearing system perceives good sound reproduction? (Yes.)

Chris

@Chris A But the basic topology of an amp can work better for a particular set of speakers because of the speakers have a demanding or unusual impedience curve?

[Chris A]

That's one answer to the first question, above.  So yes, loudspeakers usually have the greatest effect on amplifier performance. 

 

I believe a lot of people forget that point.  Generalizing amplifiers by loudspeaker brand name (or series) to me isn't very helpful or useful because loudspeakers vary within a brand quite a lot--in terms of their input impedance and their room-acoustics coupling/resulting sound fields, and their other limitations/distortions. 

 

I like to talk about the physics or the engineering of the specific loudspeakers instead of talking brand names.  YMMV.

 

Chris

[Travis In Austin]

1 minute ago, Chris A said:

That's one answer to the first question, above.  So yes, loudspeakers usually have the greatest effect on amplifier performance. 

 

I believe a lot of people forget that point.  Generalizing amplifiers by brand name, to me, isn't very helpful or useful because loudspeakers vary within a brand quite a lot--in terms of their input impedance and their room-acoustics coupling/resulting sound fields, and their other limitations/distortions. 

 

I like to talk about the physics or the engineering of the specific loudspeakers instead of talking brand names.  YMMV.

 

Chris

I was wondering because I have seen you and MikeTN talk in very technical terms that a particular model of speakers might not sound as good with a particular tube amp topology and the common factor in these discussions seems to be impedience. 

 

While it make one type of amp work harder than another, is it more likely to be an audible difference?

[Travis In Austin]

Just now, dwilawyer said:

5 minutes ago, Chris A said:

Chris

I was wondering because I have seen you and MikeTN talk in very technical terms that a particular model of

I think they talk about this a lot in the type amp and as amp sectioons as well.

[Chris A]

If you are using amplifiers whose output impedance is getting close to the input impedance of the loudspeakers (i.e., within 10x on the Ohm scale), then you have coupling and woofer damping (moving mass) differences in amplifier performance with the particular loudspeakers that you're using.  What kind of amplifiers-loudspeakers do we hear this most prominently?  Tube amplifiers coupled to loudspeakers having very non-flat input impedances.

 

If you design an amplifier to have 10x higher output impedance than the input impedance of the loudspeaker (like Nelson Pass did with his First Watt F-1 and F2 models and some of his earlier Zen DIY designs), then you're getting into a different regime--called "transconductance amplifiers" or "current source" amplifiers.  When you use an amplifier that's within 10x the same output impedance as the input impedance of the loudspeaker, what you're really doing is changing the phase and amplitude response of the loudspeaker vs. frequency, based mostly on the input impedance changes in the loudspeaker.  In the parts of the frequency spectrum where the loudspeaker input impedance is high, the amplifier pushes harder and the output of the loudspeaker gets a little louder.  In those areas where the loudspeaker input impedance goes low, the loudspeaker loudness tends to decrease a little.

 

So if you have a loudspeaker with a very non-flat input impedance curve (i.e., like Klipsch Heritage and other models such as early model Klipschorn, La Scala, Belle, Cornwall, and Heresies using autoformers to balance their frequency response), they tend to react more strongly to changes in amplifier output impedance--more audibly so.  But note that most of what you're doing by changing out amplifiers is the same thing as using a pretty good EQ unit upstream of the amplifier. 

 

But there is one more effect occurring, I believe...

 

On the flip side, it looks to me as if the reverse is true for damping/coupling: where you've got low input impedance of the loudspeaker, it tends to reverberate with the amplifier output so that you hear a very faint "reverb effect" at something like 40-50 dB down on the transients due to acoustic reflections back into the loudspeaker from the room, giving the listeners a very slightly greater sense of depth to the music.  It does this because the damping factor is lower in these frequency bands.  Some people like this.  (It's not in the recorded music, however.) This effect tends to only show up in very small listening rooms (and many thanks to Bob Carver for identifying this effect and explaining it, and the mikeTN for measuring it [albeit at the highest input impedance points of the TAD/Jubilees]).  It's a very faint effect that the human hearing system is apparently very sensitive to subconsciously. You could also simulate some of this effect by using a variable reverb box of very short reverberation times. 

 

Chris

[Travis In Austin]

Just now, Chris A said:

If you are using amplifiers whose output impedance is getting close to the input impedance of the loudspeakers (i.e., within 10x on the Ohm scale), then you have coupling and woofer damping (moving mass) differences in amplifier performance with the particular loudspeakers that you're using.  What kind of amplifiers-loudspeakers do we hear this most prominently?  Tube amplifiers coupled to loudspeakers having very non-flat input impedances.

 

If you design an amplifier to have 10x higher output impedance than the input impedance of the loudspeaker (like Nelson Pass did with his First Watt F-1 and F2 models and some of his earlier Zen DIY designs), then you're getting into a different regime--called "transconductance amplifiers" or "current source" amplifiers.  When you use an amplifier that's within 10x the same output impedance as the input impedance of the loudspeaker, what you're really doing is changing the phase and amplitude response of the loudspeaker vs. frequency, based mostly on the input impedance changes in the loudspeaker.  In the parts of the frequency spectrum where the loudspeaker input impedance is high, the amplifier pushes harder and the output of the loudspeaker gets a little louder.  In those areas where the loudspeaker input impedance goes low, the loudspeaker loudness tends to decrease a little.

 

So if you have a loudspeaker with a very non-flat input impedance curve (i.e., like Klipsch Heritage and other models such as early model Klipschorn, La Scala, Belle, Cornwall, and Heresies using autoformers to balance their frequency response), they tend to react more strongly to changes in amplifier output impedance--more audibly so.  But note that most of what you're doing by changing out amplifiers is the same thing as using a pretty good EQ unit upstream of the amplifier. 

 

But there is one more effect occurring, I believe...

 

On the flip side, it looks to me as if the reverse is true for damping/coupling: where you've got low input impedance of the loudspeaker, it tends to reverberate with the amplifier output so that you hear a very faint "reverb effect" at something like 40-50 dB down on the transients, giving the listeners a very slightly greater sense of depth to the music.  It does this because the damping factor is lower in these frequency bands.  Some people like this.  (It's not in the recorded music, however.) This effect tends to only show up in very small listening rooms (and many thanks to Bob Carver for identifying this effect and explaining it, and the mikeTN for measuring it [albeit at the highest input impedance points of the TAD/Jubilees]).  It's a very faint effect that the human hearing system is apparently very sensitive to subconsciously. You could also simulate some of this effect by using a variable reverb box of very short reverberation times. 

 

Chris

Thank you, now even I can almost understand it.

[vasubandu]

3 hours ago, Schu said:

Good amps are usually made with better components tighter specifications that compound the cost of a new unit. 

 

Yeah we hear that a lot about everything.  Would be nice if someone gave a parts list so that I  could actually verify the price.  Reminds me of Integra receivers.  You know, the ones that Onkyo makes with betters components and tighter specifications?  Actually no, at least according to what I have read, which included a systematic break down that I cannot find.  

 

The thing is, with most components, it does not cost any more to make higher quality once it has been established .  

 

And then there is the question of what is the actual cost of all the components is a $2,000 amp?  

 

I don't know the answers to these questions.  I am just saying that people should ask and not take vague BS for an answer.

[vasubandu]

@DizRotus that is precisely my point. Given the cost of Class D amps like the TI, why are they so expensive?  And why aren't they using state of the art parts?  It seems like a market wide open for someone to turn upside down.

[vasubandu]

@Chris A that was extremely helpful.  I raised this point because it does seem to me that in a world where everything is changing, Audio in general and amps in particular have not.  We throw things away because they are three months old, but 30 year old speakers are worth half or more of their original value.  And while I like to taunt the amp people over the state of things, if there were a quick and easy way to produce a better amp for a quarter of the price, they would be all over it in a heartbeat.

 

All of that is a big part of what fascinates me about audio.  Why are we stuck in the past so to speak?  I think it is because sound ultimately is physical.  You can't digitize vibrations, and all that technology has figured out how to do is to make the physical easier to access.  For me at least, there is a certain comfort in knowing that my audio experience is essentially the same as  that of people who lived a hundred years ago.

[willland]

You definitely do not need to pay $2000.00 for an amp.  

 

The most I ever paid for an amp is $600.00 and that includes the following:

 

Acurus

A100, A100X3, A150, A150, A200, A200, A200X3, 200X3, 200FIVE, 200FIVE, A250, A250

 

Adcom

GFA-6000

 

Anthem

PVA-7

MCA-2

 

B&K

Reference 4430

EX4420

 

Marantz

MA-500, MA-500

MA-700, MA-700, MA-700, MA-700, MA-700

 

NAD

925THX

 

Sunfire

Cinema Grand 200 5 channel

 

 

Of all the mentioned amps above, only two of them had any type of failure and I bought them knowing those facts.

 

Bill

 

[DizRotus]

47 minutes ago, vasubandu said:

@DizRotus that is precisely my point. Given the cost of Class D amps like the TI, why are they so expensive?  And why aren't they using state of the art parts?  It seems like a market wide open for someone to turn upside down.

 

Behringer iNukes are affordable class D amps.  They’re a good value, especially those with DSP, but keep in mind the power claims are inflated.  Notwithstanding Behringer’s hyperbolic power claims, there is plenty of low distortion power available to drive efficient Klipsch speakers.

[Travis In Austin]

2 minutes ago, vasubandu said:

@Chris A that was extremely helpful.  I raised this point because it does seem to me that in a world where everything is changing, Audio in general and amps in particular have not.  We throw things away because they are three months old, but 30 year old speakers are worth half or more of their original value.  And while I like to taunt the amp people over the state of things, if there were a quick and easy way to produce a better amp for a quarter of the price, they would be all over it in a heartbeat.

 

All of that is a big part of what fascinates me about audio.  Why are we stuck in the past so to speak?  I think it is because sound ultimately is physical.  You can't digitize vibrations, and all that technology has figured out how to do is to make the physical easier to access.  For me at least, there is a certain comfort in knowing that my audio experience is essentially the same as  that of people who lived a hundred years ago.

I think you are over analyzing it.

 

To some people tube amps sound better than solid state.  To some people SET amps sound better than push-pull.

 

The amount of negative feedback, or any at all, make a difference to some people in how things sound.

 

If something sounds better to your ears that is the ultimate test.  Are you happy with it.  Some are never happy (satisfied) and keep swithiching out gear, and that's cool too.

 

Here is another thing that Chris has been instrumental in educating Pepole about.  Once you get to a certain level of audio reproduction, the source becomes more and more critical.  This is more in 2 channel than HT, but is true of 5.1 Sacd and DVD-A: Technology can go too far in making things smaller, lighter or more convenient.   Things like compression of audio files (MP3) streaming, etc.  Music can become over-processed in the recording, mixing and mastering stages.

 

You are seeing a major swing right now in music delivery industry segments developing much higher requirements and standrds for digital music files, video uploading.  HIgh rez downloads are increasing, and hi rez streaming is on a major rise.

 

 

[Chris A]

1 hour ago, vasubandu said:

...if there were a quick and easy way to produce a better amp for a quarter of the price, they would be all over it in a heartbeat...All of that is a big part of what fascinates me about audio.  Why are we stuck in the past so to speak?

Yes.  It seems that nostalgia has taken over a lot of subject areas like audio and other things of leisurely interest.  I'm as much a student of history as anyone else when it comes to audio, but for me the bottom line is the sound that I hear, not really nostalgia.  For others, that may be different. 

 

Travis has also inferred what's happening: as you get farther and farther out on the tree branch of "better sound reproduction", other things begin to make a much bigger difference in sound.  For me, once I got the loudspeakers/room under control, my attention then turned to the recordings themselves.  I believe that many people fight the room acoustics/loudspeaker thing continuously, some because there is a lot of BS out there that drives them away from "better sound" in my experience.  I've been more of a student of the physics and psychophysics rather than things like branding and esthetics.  I've learned a lot and I've had a very good teachers: Roy Delgado and Paul Klipsch, and others--notably Floyd Toole but also many other writers...on how to achieve low distortion, good sound. 

 

Loudspeakers of the type of Klipsch Heritage have stuck to the fundamentals of what makes music sound better--and they have held their value as a consequence. They don't wear out and they don't become "obsolete".  While it seems to me that the small loudspeaker crowd (those that invest in direct radiating loudspeakers chosen more for how they look in a room rather than how they sound) have apparently continuously chased an elusive goal that never seems to fully materialize for them.  Some people apparently give up and get used to the sound of those type of loudspeakers, adjusting their tastes to accept what they hear from them.  Others continue to chase better sound all of their adult lives.  This is the issue for anyone that's a "maximizer" in this subject domain. 

 

I personally believe in value in hi-fi audio.  There are apparently a lot of people that will take your money for better zipstrip light cords and connectors and very high priced electronics (...a lot of people...).  The moment that you start making choices based on looks and/or product image rubbing off on you, you start to trade away better sound for the appearance of better sound.  Once you get past actually good loudspeakers and room acoustics, spending a lot of money on expensive gear upstream typically doesn't get you a lot in my experience.  Some people apparently want to believe that they can put all their money into expensive electronics and then use mediocre loudspeakers/listening space--and achieve the same or better results.  It just doesn't work like that.

 

YMMV.

 

Chris

[vasubandu]

9 minutes ago, Chris A said:

Loudspeakers of the type of Klipsch Heritage have stuck to the fundamentals of what makes music sound better--and they have held their value as a consequence. They don't wear out and they don't become "obsolete".  While it seems to me that the small loudspeaker crowd (those that invest in direct radiating loudspeakers chosen more for how they look in a room rather than how they sound) have apparently continuously chased an elusive goal that never seems to fully materialize for them.  Some people apparently give up and get used to the sound of those type of loudspeakers, adjusting their tastes to accept what they hear from them.

 

Chris, this was me when I wandered in here. I was focused on the Definitive XTR series because they produce awesome sound and are only 1.5 inches deep.  Plus you stick them on the wall so they blend perfectly with TV.  I was fortunate to strike up conversations with a few people here and to pay attention to their advice. And now I have a 45 pound center speaker that I adore.

 

I tend to be a generalist and a dabbler in everything, and I very much doubt that I will ever get anywhere near your depth of knowledge and refinement.  My own "good enough" level won't be all that high in part because the learning is more fun for me than the listening.  But I am always amazed and impressed when I meet people who master a subject instead of dabbling in it. And I am grateful because without such people, I could not get away with my dabbling. 

 

What you said makes sense, and now I understand the idea of $2,000 CD players and whatever it is that makes some CDs special.  Those would have no significance at all until the rest of your system performs at a level where they become the weak link and it will make a difference.  Must be a never-ending chase because as soon as that is fixed, something else becomes the weak link.

[DizRotus]

2 hours ago, Chris A said:

Travis has also inferred what's happening . . .

 

I’m not trying to be the grammar police, but did you mean “implied?”  It seems like you are interpreting what Travis suggested, rather than guessing at what he understood.  It makes a difference, and it’s not clear from the context.  Thanks.