computer audiophile on the cheap Class D amplifiers, can a chip sound as good as a regular amplifier?

[bigbob]

55 minutes ago, jhwalker said:

 

Similarly, Pioneer has been using class D amplification in its Elite line of receiver for 5+ years, and they get great reviews (and sound great - I have one).

 

Yes, and the original OP speculated what the Grateful Dead's "Wall of Sound" would have been like back in 1974, when it took three semi-trailers to move it from venue to venue. With "D" Amps, they could have used a single truck...

 

I see Class D (classdaudio.com) amplifiers with an Audiophile price tag.  I am very impressed with this $40 unit, I am intrigued what ten times the price would sound like.

[bigbob]

1 hour ago, Jud said:

 

As for the tech not existing you are clearly wrong.  Just Google Bruno Putzeys.

 

Now what sound quality there is sub $1400, where very good amplifiers based on modules designed by Putzeys are available, I don't know.  But I can only applaud BigBob's quest to find sound he loves "on the cheap," and will follow with interest.

 

Thanks, I love High Fidelity Cables MC-0.5, but really don't understand how Rick Schultz has made Magnets make Music, but it does. If the music that comes out of my Advents is pleasing to my ears (which it is) I don't see what money has to do with it.

 

Audiophiles get a great Ego-investment equal to the amount of money invested in their system--and I understand that. I have nothing 'against' $250,000 Wilson Audio custom speakers, but I can't afford them. What I do understand is that I have 4 Tb of Computer based audio-files, and I like listening to good music. My speakers were brand new in 1975 with a new foam rings installed in 1990. And the music sounds magical, mainly because I  have made a few affordable tweaks.

 

[Abtr]

My JBL SLR305 active speakers have STA350BW DSP + class D power amp chips and sound really good. I also have a Wyred4Sound ST500 MKII class D stereo power amp, feeding KEF LS50s, which sounds even better.

[bigbob]

1 minute ago, Abtr said:

My JBL SLR305 active speakers have STA350BW DSP + class D power amp chips and sound really good. I also have a Wyred4Sound ST500 MKII class D stereo power amp, feeding KEF LS50s, which sounds even better.

 

And if it sounds good to you, that is all that matters...

[esldude]

34 minutes ago, bigbob said:

 

And if it sounds good to you, that is all that matters...

 

Well yes, and no. 

 

See the reason it sounds good is it performs very well for the purpose.

 

The class doesn't mean beans about sound quality.  It is the implementation and the resulting performance in the audible band.  Class D has the potential to be quieter, cleaner, and more powerful than other classes.  Some are reaching that potential.  At ever cheaper prices some are getting good enough you have trouble matching sound quality with other classes without spending more money to do so. 

 

Audiophiles listen with their eyes way too much.  Plus they hang onto old tech as automatically being better so that it has to be beaten into their heads for years before they realize the new tech has equalled or surpassed the old.

 

Of dozens of possible examples here is one.  Chips, op-amps specifically.  No good.  Useful only for cheap lousy sound like maybe you get in car stereo systems.  I have a receiver from the 1980's with the box.  On the side of the box is the slogan about discrete beats chips.  With cartoon picture of a bipolar transistor pounding a poor defenseless opamp.  Odd too as the unit used FETs. 

 

So for years, and years DACs could be no good without discrete transistor output stages and preamps too.  Now people brag about which high speed opamp they have in the DAC output stages, and pre-amps just rather ignore the issue.  Also not uncommon is getting these slipped in by "reputable" makers of good gear and getting acclaim aplenty.  In the case of preamps one of the early Audio Research solid state preamps (hallowed be thy name ARC) got wonderful reviews and acceptance.  Heart of this preamp was a few opamps which they disguised by potting them in epoxy and calling them special "gain modules". 

 

Class D is already better than is acknowledged much further up the food chain (and in the case of Bruno's work it might be the top of the food chain).  If you end up needing more zip for your zap, some of the rather inexpensive pro amps might be a ticket for you.  Now unfortunately those get listed as being 500 or 1000 watts like this Crown for $299.

 

https://www.amazon.com/Crown-XLS1000-Power-Amplifier/dp/B003HZPKSM

 

Now those numbers are at rather high distortion.  What you do get however is an awfully clean nice sounding amp of about 150 watts with some headroom. 

 

There'll always be somebody with class A triodes looking down on the guy with class A solid state who knows his units have no crossover distortion like those class AB transistor amps have inherently who know the long pedigree behind their gear beats goofy switching amps and their switching noise.  You'll also notice a general trend.  More power, lower distortion, better energy efficiency and superior measured fidelity at lower prices as you ascend from the hallowed heavens into the modern world of junky sounding gear.  Yet somehow these modern systems with modern gear design sound better than ever.  Funny don't you think?

 

As a disclaimer:  I have JBL LSR305s and use a Wyred4Sound ST500 to power my very power hungry Soundlab electrostats. 

[Jud]

6 minutes ago, esldude said:

With cartoon picture of a bipolar transistor pounding a poor defenseless opamp.  Odd too as the unit used FETs. 

 

Good stuff.

[unbalanced output]

Ralf - the industry norm for "hi-fi" level components is class A to have for pre-amps and class A/B for amps. I agree with Supperconductor, class D are becoming better. Mosfet amps from 20 years ago were terrible, but the industry has pushed a lot in this field due to the significant price advantages of PWM circuits. 

 

Bob, your quest is certainly commendable. For the last few years since I moved overseas, I've been living off computer speakers at home which cost me less than a box of chocolates. My "hifi" rig has always been my headphone rig and I've been living happily this way. Just now I've decided to build a stereo system. Anyhow, what I wanted to say is that we sometimes tend to overspend on our hobbies, and sometimes we should take a more frugal approach to life. 

 

Vintage equipment may be a good option, however in order to get the best value for the money I would make sure that the particular model I was buying would be a really good quality one and I would have the amp serviced and recapped. Without doing this, I wouldn't really bother due to the risk of bringing a lemon to the living room. 

[GUTB]

Class D is inherently inferior. This inferiority will be present until  switching amplifiers can go significantly higher in the frequency band than they can do so currently. This is not a matter of personal opinion, but a matter of physical limitations.

 

Now, what people with lower standards in audio will accept as "high end" is another discussion. For example. I just finished auditioning a class D amp over a period of 3 weeks -- D-Sonic M3-800S, which uses the latest Pascal modules and a custom input board. The Pascal modules use technical wizardry that goes way over my head to reduce switching noise to levels previously not possible. Compared with my cheap 845 SET, the D-Sonic was clearly superior in terms of resolution, control and dynamics. Bass was perhaps lean, but by no means anemic -- certainly tauter than what my 845 could handle. But where the D-Sonic fell down, and ultimately caused me to return the unit, was its inability to cast a three-dimensional soundstage (ie, lacked depth), and inability to produce a "correct" (or "pleasant"?) timbre. So, it was super resolving and agile, but couldn't make me miss it at all when I would turn back on the 845. In fact, the 845 was a relief in comparison.

 

What happened here was that the sound was compromised by the fact it is class D. Switching artifacts were present in the audio band, and the design features of the amp that tried to mitigate those problems ended up compromising the sound. This is the cause of the class D listener's fatigue phenomena. If your standards are low than this amp would probably be phenomenal. Certainly, it was by FAR the best class D amp I've ever heard. Class D is getting there. Once technology exists to address the switching noise issue properly I can see that class D will be the amplifier of choice for audiophiles.

[bigbob]

18 minutes ago, unbalanced output said:

 

Vintage equipment may be a good option, however in order to get the best value for the money I would make sure that the particular model I was buying would be a really good quality one and I would have the amp serviced and recapped. Without doing this, I wouldn't really bother due to the risk of bringing a lemon to the living room. 

 

Well, that's where Sasa, my electronics technician comes in to play. A key to the "Computer Audiophile on the Cheap" is knowing a technician who can make the minor repairs, blow out the dust bunnies, check some voltages and such and "make it better than new"... He said anything that is broke on the older stuff can be fixed, if not improved, because the components used thirty years ago have been improved upon.

[bigbob]

6 minutes ago, GUTB said:

This is the cause of the class D listener's fatigue phenomena. If your standards are low than this amp would probably be phenomenal. Certainly, it was by FAR the best class D amp I've ever heard. Class D is getting there. Once technology exists to address the switching noise issue properly I can see that class D will be the amplifier of choice for audiophiles.

 

 

Okay, so because I am disabled, and I live on a disability income, my standards are so very low that my $40 Class-D amplifier, with the $10 power supply sounds quite good--even "probably be Phenomenal."

 

"Oh, you poor peasant, you have never heard my system, which I spent Thousands of dollars on, therefore you pitiful little people will never be as good as me."

 

What I think is that you are pompous, and what I have forgotten about stereo exceeds anything you will ever attain. If you think my $40 Class D Amplifier with a $10 power supply is so threatening, I am reminded about the guys with huge tires on their pick-up trucks--they are compensating for their inadequacies, and have very small hands.

[Jud]

Oh dear, poor GUTB.  Can't ever change a position once taken, so can't learn anything new.  And what he has learned comes from marketing literature, which tends to make these overbroad always-wrong flat statements like "Class D is inherently inferior."

 

It's OK, GUTB.  As Journey sings, "Don't stop believin'!"  

[bigbob]

1 hour ago, esldude said:

  You'll also notice a general trend.  More power, lower distortion, better energy efficiency and superior measured fidelity at lower prices as you ascend from the hallowed heavens into the modern world of junky sounding gear.  Yet somehow these modern systems with modern gear design sound better than ever.  Funny don't you think?

 

As a disclaimer:  I have JBL LSR305s and use a Wyred4Sound ST500 to power my very power hungry Soundlab electrostats. 

 

I agree that modern designs do often sound better. I think the general public--who are the target market of any mass marketer of "Stereo" would rather have a 5.1 Surround Home Theater system that all comes in one box, and is on sale at Walmart. Then there are people like me, who fell in love with a pair of ESS Heil ATM speakers, playing "Tubular Bells". I can still hear the decay of the bell... I could not afford a pair, back in 1974, but I had the good sense to buy a pair of Advent Large Loudspeakers with some Student Loan money the next year, and started collecting Jazz on vinyl. I got bit by the bug, Audiophilia.

Only an Audiophile--no matter the cost of his rig-- is always searching for the new tweak that is finally going make the sound that bit them.

Come the computer, and 24/96 HD Audio files, and I still have the Advents. I still have the Yamaha Receiver with Natural Sound and the Direct-circuit, and I think after almost forty years of burn in, it is still very listenable. Then the right channel developed an idiopathic condition-- it would just start sounding scratchy and distorted-- and then it would go away. Unpredictable, and a pain in the seat. One trip to the shop, and it still did it from time to time. It is a RX135, an entry level receiver that served me well. My technician played it for three days, and it sounded fine. I bring it home, and it is still doing it. That's when I ordered a $40 Nobsound. I figure, "How Bad can it be?" and "If it really sucks, I can always send it back."

My surprise--it didn't sound too bad, right out of the box, and I was using an old 12v wall-wort as the PS. There was ENOUGH potential, I went ahead and ordered a 24v PS. Now I have a $50 amplifier that is compared to no one's stereo. It sounds good to me-- and the right channel doesn't have Poltergeist... Can I really want for anything more?

[bigbob]

11 minutes ago, Jud said:

Oh dear, poor GUTB.  Can't ever change a position once taken, so can't learn anything new.  And what he has learned comes from marketing literature, which tends to make these overbroad always-wrong flat statements like "Class D is inherently inferior."

 

It's OK, GUTB.  As Journey sings, "Don't stop believin'!"  

 

Amen...

[unbalanced output]

27 minutes ago, bigbob said:

 

Well, that's where Sasa, my electronics technician comes in to play. A key to the "Computer Audiophile on the Cheap" is knowing a technician who can make the minor repairs, blow out the dust bunnies, check some voltages and such and "make it better than new"... He said anything that is broke on the older stuff can be fixed, if not improved, because the components used thirty years ago have been improved upon.

 

Fair play! I would personally fancy an old Naim Nait, I may do it for a second system in the future when I need one - not something for now.

 

Jud, I'm sorry but GUTB is right on this one. It is not a matter of "belief" that class D is an inferior approach - that's just the physical truth behind the architecture. There may be shitty class A amp implementations and good class D ones, however "inherently" as he said it is a fact fact of life that a single linear gain is superior to a quantised signal modulator. This could be easily shown mathematically. 

[plissken]

1 hour ago, bigbob said:

 

 

Okay, so because I am disabled, and I live on a disability income, my standards are so very low that my $40 Class-D amplifier, with the $10 power supply sounds quite good--even "probably be Phenomenal."

 

"Oh, you poor peasant, you have never heard my system, which I spent Thousands of dollars on, therefore you pitiful little people will never be as good as me."

 

What I think is that you are pompous, and what I have forgotten about stereo exceeds anything you will ever attain. If you think my $40 Class D Amplifier with a $10 power supply is so threatening, I am reminded about the guys with huge tires on their pick-up trucks--they are compensating for their inadequacies, and have very small hands.

 

You are on the money. Class D can be very good and SMA's have been around a very long time. I used to own the Carver Cube DECADES ago. There are certainly, middling performing at best, $12,000 25 watt amps out there. 

 

Don't worry about it since GUTB doesn't actually know what he/she is talking about. 

 

[plissken]

40 minutes ago, unbalanced output said:

 

Fair play! I would personally fancy an old Naim Nait, I may do it for a second system in the future when I need one - not something for now.

 

Jud, I'm sorry but GUTB is right on this one. It is not a matter of "belief" that class D is an inferior approach - that's just the physical truth behind the architecture. There may be shitty class A amp implementations and good class D ones, however "inherently" as he said it is a fact fact of life that a single linear gain is superior to a quantised signal modulator. This could be easily shown mathematically. 

 

When the output stage reconstruction filter shows you the exact same signal on a scope as a Class A amp you have the same signal. 

 

 

[Ralf11]

Many Class D amps have been very highly reviewed (but the ones I've seen ar not cheap).

 

I am very interested on why exactly "class D is an inferior approach" -- post what specifically "the physical truth behind the architecture" is....

 

If you think it is switching noise then that is outside the pass band of most filters, and GaN promises to allow even gentler filtering if that is the concern (OTOH, the only GaN designs I know of are $35k or more).  But that will change.

 

Maybe a list of xlnt sounding Class D amps is in order?

I have heard great things about the Bel Canto and nad M series (have not compared them myself and they aren't cheap).

[unbalanced output]

I see you didn't understand (or didn't care to understand), so I'm not going to argue... 

[GUTB]

8 minutes ago, plissken said:

 

When the output stage reconstruction filter shows you the exact same signal on a scope as a Class A amp you have the same signal. 

 

 

 

I take this to mean that you've never listened to class A and class D amps side by side.

[plissken]

1 minute ago, GUTB said:

 

I take this to mean that you've never listened to class A and class D amps side by side.

 

Oh, but I have... 

[GUTB]

8 minutes ago, Ralf11 said:

Many Class D amps have been very highly reviewed (but the ones I've seen ar not cheap).

 

I am very interested on why exactly "class D is an inferior approach" -- post what specifically "the physical truth behind the architecture" is....

 

If you think it is switching noise then that is outside the pass band of most filters, and GaN promises to allow even gentler filtering if that is the concern (OTOH, the only GaN designs I know of are $35k or more).  But that will change.

 

Maybe a list of xlnt sounding Class D amps is in order?

I have heard great things about the Bel Canto and nad M series (have not compared them myself and they aren't cheap).

 

I'm simplifying things a great deal, but class D operation results in artifacts in the audio band. The techniques used to filter those artifacts out leads to a compromise of the sound. Mathematically speaking they would need to operate at a much higher frequency to mitigate this problem. The GaN FETs you are talking about are the next step towards realizing that goal, but if I recall correctly you'd need to have something like 5x higher frequency, and GaN is 2x.

[GUTB]

6 minutes ago, plissken said:

 

Oh, but I have... 

 

I find that hard to believe considering how massive the difference is.

[plissken]

You do realize that Class a was a solution to the problem of transistor cross over distortion.

[Ralf11]

"class D operation results in artifacts in the audio band"

 

contra what I understand unless you mean the audio band for dolphins...

[GUTB]

1 minute ago, Ralf11 said:

"class D operation results in artifacts in the audio band"

 

contra what I understand unless you mean the audio band for dolphins...

 

Artifacts. Obviously you can't here the switching itself. Until technology improves to the point where this problem can be transparently mitigated, class D will remain inferior.