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

[bigbob]

I have been exploring inexpensive "Class D" chip amplifiers. I was wondering if you could actually listen to an amplifier that is nothing more than a chip, a power supply and a volume control.

 

And the answer is "Yes" and as a matter of fact, it doesn't sound all that cheap.... I purchased a Nobsound 50wx2 Mini Power Amplifier for $40, and shelled out an additional $10 for a 24v power supply.

It sounds good.

 

Then I started reading about this kind of amplifier, and oh, boy is there a number of folks who dismiss them without question. I have never been one to read a review and agree with the writer, before I listen myself.

 

As "Computer Audiophile on the Cheap", a $50 amplifier goes right along with a $99 Schiit Modi 2, and the Schiit SYS passive pre-amp I already own. Generally speaking I favor "Vintage" electronics (By Vintage, I mean, ones that don't even have a CD-input-- mid 1980s receivers before Surround Sound and Home Theaters took over the marketplace)

They built some great electronics back then, and a quick check at the Salvation Army Thrift store or Craigslist will get you a chunking beast of an amp for less than $100. They can be re-capped and repaired, if you have a good technician around, and if all else fails, you can always find another one...

\

So why buy a $40 amplifier, that doesn't even have a power cord? Curiosity more than anything else. I didn't know what to expect, and I have seen rave reviews for what FleaWatt Audio is doing with this chip. Some folks dismiss the whole idea as not worthy of any serious consideration. 

I am a cheap-skate by nature, and although $40 doesn't break the bank, I expected something that would sound like "a $40 amplifier". I was surprised as just how good it sounded right out of the box, with a recycled 12v 'wall-wort' power supply. I figured it was pumping out 12 watts per channel into 8 ohm speakers. So, I went ahead and ordered the 24v adapter, which seems to put out 30w per channel, if I am reading the Texas Instrument data sheet correctly.

 

Does it sound as good as a 1980s era receiver? It sounds different. Different is neither bad nor good, it is just a different sound. But that same could be said about the harman/kardon h/k330i vs. the Yamaha RX-135.

 

After two albums, do your ears hurt, or do you want to listen to two more?

 

I found it surprisingly bright and punchy, without distortion or "gritty" overtones.

 

Will it be the prime amplifier in my system? Probably not, but it is certainly good enough for a secondary system--like back in the bedroom, with the laptop and a Dragonfly USB DAC, and a pair of Polk bookshelf speakers.

 

It seems that Class-D amplifiers have caught on with the PA systems, where 90% efficiency and lightweight are a consideration. Yamaha is building them, which makes me ponder what the Grateful Dead's "Wall of Sound" would have been like with Class D amplifiers. They could have cut the number of semi-tractor-trailers from three to one during the 1974 tour.

 

[Ralf11]

GaN FETs should give even better SQ, once they become affordable.

[Silly goose]

I like how technology is making things better and cheaper. However I refuse to sell out our own citizens by buying Asian products that are available from local companies just to save a dime. That's the least patriotic thing anyone can do. 

[bigbob]

16 minutes ago, Silly goose said:

I like how technology is making things better and cheaper. However I refuse to sell out our own citizens by buying Asian products that are available from local companies just to save a dime. That's the least patriotic thing anyone can do. 

Well the admin has already quashed a political debate on this forum, and judging from your profile photo, I think I know where you are headed here.  If you think $40 amplifiers are why China has a trade surplus, then is there any real reason to reply? Texas Instruments makes the chips. I have no idea whether a Chinese slave labor camp is doing the soldering, nor do I much care. If I had any skills with a soldering gun, and knew how to read a schematic, I am pretty sure I could DIY a TPA3116 into a functional amplifier for the cost of components, and the chip--right here in the good old USA. And lacking those skills, I could buy one from Fleawatt for $400...but this OP is about the Nobsound $40 amplifier, not a platform for jingoistic Pride In America...or am I missing your point? Both pieces of Schiit are made in America, and for the record Schiit has no interest in Class-D amplifiers. I already asked.....

[Silly goose]

2 minutes ago, bigbob said:

Well the admin has already quashed a political debate on this forum, and judging from your profile photo, I think I know where you are headed here.  If you think $40 amplifiers are why China has a trade surplus, then is there any real reason to reply? Texas Instruments makes the chips. I have no idea whether a Chinese slave labor camp is doing the soldering, nor do I much care. If I had any skills with a soldering gun, and knew how to read a schematic, I am pretty sure I could DIY a TPA3116 into a functional amplifier for the cost of components, and the chip--right here in the good old USA. And lacking those skills, I could buy one from Fleawatt for $400...but this OP is about the Nobsound $40 amplifier, not a platform for jingoistic Pride In America...or am I missing your point? Both pieces of Schiit are made in America, and for the record Schiit has no interest in Class-D amplifiers. I already asked.....

Just sharing my opinion. Yes I understand sweatshop labor can reduce costs, and I understand most people don't care. For people who don't care, they will care even less about my opinion as well. 

[wgscott]

I have this:  http://www.classdaudio.com/sds-amplifier-kits/sds-250-power-amplifier-kit/

 

Oh, and 

 

I assembled it in my own sweatshop.

[bigbob]

It might be better said, that if they could make them in the US at a profit, some entrepreneur would invest capital in the factory and spit them out by the dozens. I care about your opinion, albeit I disagree with your statement.

Some folks spend $250,000 for speakers, whilst others listen to ear-bugs. Audiophiles are a strange lot...if you take money out of the discussion--then all you have left to debate is whether it sounds good, or it makes your ears bleed.

[The Computer Audiophile]

I love ice cream and I love sushi. Just not together. I love politics and I love HiFi. Just not together. 

 

No more politics here. 

[bigbob]

3 minutes ago, wgscott said:

I have this:  http://www.classdaudio.com/sds-amplifier-kits/sds-250-power-amplifier-kit/

 

Oh, and 

 

I assembled it in my own sweatshop.

Cool, glad to see someone other than FleaWatt is building these here in God Bless America, land of the free....

[Silly goose]

2 minutes ago, The Computer Audiophile said:

I love ice cream and I love sushi. Just not together. I love politics and I love HiFi. Just not together. 

 

No more politics here. 

You need to get out more

 

http://kotaku.com/in-japan-ice-cream-sushi-exists-486191695

[bigbob]

2 minutes ago, The Computer Audiophile said:

I love ice cream and I love sushi. Just not together. I love politics and I love HiFi. Just not together. 

 

No more politics here. 

I agree. But maybe if you try some fresh salmon roe on your Haagen-Daz, we could bring you around.

 

[Melvin]

I've been using a Dayton Audio DTA-120 to power some Pioneer SP-BS22-LR bookshelf speakers at work. The amp is on sale right now for $78. After 2 years I'm still impressed with the sound. Value is off the charts. BTW bigbob, I love my Fleawatt TPA3116D2. I'll be using it in my main system during the hot summer months, replacing my tubed Chi-Fi wonder amp (APPJ PA0901A). Good sound on the cheap!

 

An afterthought .. I recently had my aging PS Audio Trio A-100 repaired. If you're not familiar with this amp it's a class d ICE amp produced about 10 years ago and sold for about $1000. I still like it and yet, I'll be using the little Fleawatt ($250) this summer. 

[bigbob]

4 hours ago, Melvin said:

I've been using a Dayton Audio DTA-120 to power some Pioneer SP-BS22-LR bookshelf speakers at work. The amp is on sale right now for $78. After 2 years I'm still impressed with the sound. Value is off the charts. BTW bigbob, I love my Fleawatt TPA3116D2. I'll be using it in my main system during the hot summer months, replacing my tubed Chi-Fi wonder amp (APPJ PA0901A). Good sound on the cheap!

 

An afterthought .. I recently had my aging PS Audio Trio A-100 repaired. If you're not familiar with this amp it's a class d ICE amp produced about 10 years ago and sold for about $1000. I still like it and yet, I'll be using the little Fleawatt ($250) this summer. 

Before I even knew what a TPA3116D2 was, I read glowing reviews of the Fleawatt and contacted Derek about building me one.

Then I started doing some research, and like most Audiophiles, I have more curiosity than cash. I saw units for $40 from Nobsound and that surely fit into the "CAOTC" criteria for affordable.

I am more impressed since the 24v power supply arrived, and I am driving two Large Advent Loudspeakers with ease.

After reading the article on Dynamic Range, I pulled up "Back in Black" and "Brothers in Arms"--which have good green numbers, and they were splendid. The Nobsound has a characteristic "clean" presentation, which for me, means it adds no coloration to the sound. I have always loved the Yamaha "Natural Sound" with the Direct circuit, for that very reason. My other amp is a h/k 330i receiver, and it adds a "warmth" to the presentation.

I must be following your lead, as a Chi-Fi Tube amplifier is next on my list. I have friends that swear by Tubes, and others that swear at Tubes. If I can get into tubes for under $200, it would be a nice auxiliary heating source during the "cold" months of Winter here in North Carolina. Plus, I want to find out what "tube rolling" is all about.

 

I keep hearing the term "exploiting" used in reference to chip amplifiers. Some folks, like Derek are exploiting the full potential of the chip, with top-shelf components, and clean power supplies. I don't have the resources to also try the TDA7492-based amps. I would recommend a chip amp to a friend who wants a 'secondary' system for their workshop, bedroom, or garage but has a small budget to work with.

 

With a Computer based Audiophile system, the source material is everything--so many 24/96 recording re-masters to re-discover.

One thing I have found to be true-- a bad vinyl rip is worse than an average red-book FLAC ripped from a Library-loaned CD.

And so much material is out there on MP3 @320, it is really splitting hairs in comparison of SQ. A beautifully engineered recording (Like Linn) will sound great every time, and some folks ought not to try and rip their records, until they understand what dynamic range is.... I had a rip of an album, that barely caused a ripple in the Spectrum Analyzer, the levels were so low. It was 24 bit-192 kHz pure garbage...and a McIntosh system could not have made it sound better...

 

 

[Melvin]

9 hours ago, bigbob said:

I have friends that swear by Tubes, and others that swear at Tubes.

 

Hahahaha .. I will admit to swearing at a tube or 2. 

 

9 hours ago, bigbob said:

If I can get into tubes for under $200, it would be a nice auxiliary heating source during the "cold" months of Winter here in North Carolina. Plus, I want to find out what "tube rolling" is all about.

 

My experience so far with the APPJ integrated has been great. Nice build and sound quality for $189 + tax. Those glass bottles do add to the warmth of the room. I look forward to your thoughts on your next purchase.

 

Thanks for starting this thread bigbob. I hope others share some of their own "cheap and cheerful" experiences. 

[bigbob]

I am done for a while. No sense buying tubes in the Summer.

 

[unbalanced output]

Wrong forum I guess, but... yes, class D amps will give you the highest watt-per-dollar you can find. IME it can be a reasonable option if the rest of the equipment is not particularly great, but only if your power demand is high for some reason. If not  - and you should not if you want good sound on the cheap - class AB amplifiers can be found for just a few bucks more than similar class D amps if you're into doing some DIY. Plug in a linear power supply and you can have a trully killer piece of equipment for the money. 

 

 

[bigbob]

1 hour ago, unbalanced output said:

Wrong forum I guess, but... yes, class D amps will give you the highest watt-per-dollar you can find. IME it can be a reasonable option if the rest of the equipment is not particularly great, but only if your power demand is high for some reason. If not  - and you should not if you want good sound on the cheap - class AB amplifiers can be found for just a few bucks more than similar class D amps if you're into doing some DIY. Plug in a linear power supply and you can have a trully killer piece of equipment for the money. 

 

 

There isn't a forum for Class-D amplifiers, and quite frankly I thought I was posting under "Computer Audiophile on the Cheap" thread.

 

But, as to your point that an AB class amplifier "for a few bucks more"--that is a subjective opinion.

 

Class D amplifiers--so-called 'chip amplifiers' have up to 90% efficiency, and with a good power supply can provide the best bang for the buck.

 

The Class AB amps I see advertised are designed for automotive applications--apparently they can be blamed for the thunderous roar I hear coming from cars with big rims. As to whether it is a listenable amplifier, I have yet to hear one, so I don't have an opinion. All I can attest to is what I have heard--and my $40 Nobsound with a $10 24v PSU--sounds great.

 

"So the class AB amplifier is a good compromise between class A and class B in terms of efficiency and linearity, with conversion efficiencies reaching about 50% to 60%."-http://www.electronics-tutorials.ws/amplifier/amplifier-classes.html 

 

 

[unbalanced output]

Hi Bob

 

Actually, car audio uses a lot of class D amps, especially for subs, exactly due to their power efficiency. Class D will always deliver the most power for the money, but not necessarily the best sound quality. They have the advantage of being inherently less sensitive to the PS due to their switching nature... so yeah price-wise a good class D would be difficult to beat. Just the class of the amplifier doesn't tell you you much - in theory, class AB is superior to class D and probably is used by the majority of hi-fi amps out there. In practice, it is hard to make "fair" comparisons due to the lack of definition of what is "fair" (comparing same prices, same powers, etc.).

[GUTB]

On 4/12/2017 at 6:16 PM, bigbob said:

I have been exploring inexpensive "Class D" chip amplifiers. I was wondering if you could actually listen to an amplifier that is nothing more than a chip, a power supply and a volume control.

 

And the answer is "Yes" and as a matter of fact, it doesn't sound all that cheap.... I purchased a Nobsound 50wx2 Mini Power Amplifier for $40, and shelled out an additional $10 for a 24v power supply.

It sounds good.

 

Then I started reading about this kind of amplifier, and oh, boy is there a number of folks who dismiss them without question. I have never been one to read a review and agree with the writer, before I listen myself.

 

As "Computer Audiophile on the Cheap", a $50 amplifier goes right along with a $99 Schiit Modi 2, and the Schiit SYS passive pre-amp I already own. Generally speaking I favor "Vintage" electronics (By Vintage, I mean, ones that don't even have a CD-input-- mid 1980s receivers before Surround Sound and Home Theaters took over the marketplace)

They built some great electronics back then, and a quick check at the Salvation Army Thrift store or Craigslist will get you a chunking beast of an amp for less than $100. They can be re-capped and repaired, if you have a good technician around, and if all else fails, you can always find another one...

\

So why buy a $40 amplifier, that doesn't even have a power cord? Curiosity more than anything else. I didn't know what to expect, and I have seen rave reviews for what FleaWatt Audio is doing with this chip. Some folks dismiss the whole idea as not worthy of any serious consideration. 

I am a cheap-skate by nature, and although $40 doesn't break the bank, I expected something that would sound like "a $40 amplifier". I was surprised as just how good it sounded right out of the box, with a recycled 12v 'wall-wort' power supply. I figured it was pumping out 12 watts per channel into 8 ohm speakers. So, I went ahead and ordered the 24v adapter, which seems to put out 30w per channel, if I am reading the Texas Instrument data sheet correctly.

 

Does it sound as good as a 1980s era receiver? It sounds different. Different is neither bad nor good, it is just a different sound. But that same could be said about the harman/kardon h/k330i vs. the Yamaha RX-135.

 

After two albums, do your ears hurt, or do you want to listen to two more?

 

I found it surprisingly bright and punchy, without distortion or "gritty" overtones.

 

Will it be the prime amplifier in my system? Probably not, but it is certainly good enough for a secondary system--like back in the bedroom, with the laptop and a Dragonfly USB DAC, and a pair of Polk bookshelf speakers.

 

It seems that Class-D amplifiers have caught on with the PA systems, where 90% efficiency and lightweight are a consideration. Yamaha is building them, which makes me ponder what the Grateful Dead's "Wall of Sound" would have been like with Class D amplifiers. They could have cut the number of semi-tractor-trailers from three to one during the 1974 tour.

 

 

 

The answer is "no".

 

Sorry.

 

Here's the problem: switching noise. Class D amplification, currently, results in switching noise artifacts in the audio band. To defeat the switching artifacts, filtering can be used, but which ends up compromising the sound. In order to use filters that don't compromise the sound, switching has to occur at much higher frequencies than it does currently. Eventually, the technology will exist to make class D the go-to for audiophiles -- it's not here yet.

[bigbob]

16 minutes ago, unbalanced output said:

Hi Bob

 

Actually, car audio uses a lot of class D amps, especially for subs, exactly due to their power efficiency. Class D will always deliver the most power for the money, but not necessarily the best sound quality. They have the advantage of being inherently less sensitive to the PS due to their switching nature... so yeah price-wise a good class D would be difficult to beat. Just the class of the amplifier doesn't tell you you much - in theory, class AB is superior to class D and probably is used by the majority of hi-fi amps out there. In practice, it is hard to make "fair" comparisons due to the lack of definition of what is "fair" (comparing same prices, same powers, etc.).

The more I read about Class D amplifiers, the more curious I became. First, my opinions come from my ears, not my heart. I really don't have a "dog in the fight" in class warfare.

 

I bought a $40 Nobsound out of curiosity, and it sounded "OK" using a recycled 12v wall wort. When the 24v PSU arrived, it sounded "better".

 

I have a 1980s-era harman/kardon receiver which I assume is AB. It sounds good also. But, I am NOT willing to let other's opinion about the SQ of my stereo choices affect my opinions.

 

I live on a very limited income, hence "Computer Audiophile on the Cheap" is about choices. My first choice is Vintage electronics--ones you find at garage sales, on Craiglist, or at the Thrift store. By "Vintage" they are generally very affordable, and repairable.

 

My recommendation of a class D amplifier, as a good choice for a second system--for the bedroom, or the garage, or workshop.

[bigbob]

17 minutes ago, GUTB said:

 

 

The answer is "no".

 

Sorry.

 

Here's the problem: switching noise. Class D amplification, currently, results in switching noise artifacts in the audio band. To defeat the switching artifacts, filtering can be used, but which ends up compromising the sound. In order to use filters that don't compromise the sound, switching has to occur at much higher frequencies than it does currently. Eventually, the technology will exist to make class D the go-to for audiophiles -- it's not here yet.

Hmmm so a $40 chip amplifier with a $10 power supply is not good enough for the Audiophile, at least not yet..  I guess Yamaha has not got the memo... http://www.yamahaproaudio.com/global/en/products/poweramps/

[jhwalker]

7 minutes ago, bigbob said:

Hmmm so a $40 chip amplifier with a $10 power supply is not good enough for the Audiophile, at least not yet..  I guess Yamaha has not got the memo... http://www.yamahaproaudio.com/global/en/products/poweramps/

 

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).

[Jud]

26 minutes ago, GUTB said:

 

 

The answer is "no".

 

Sorry.

 

Here's the problem: switching noise. Class D amplification, currently, results in switching noise artifacts in the audio band. To defeat the switching artifacts, filtering can be used, but which ends up compromising the sound. In order to use filters that don't compromise the sound, switching has to occur at much higher frequencies than it does currently. Eventually, the technology will exist to make class D the go-to for audiophiles -- it's not here yet.

 

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.

[Ralf11]

what are some good class AB amps?

[Supperconductor]

I used to hate Class D amps - never liked the sound. Then I heard some at a hifi show and was really shocked that I liked the sound. The design and implementation have evolved quite a bit. So I purchased them on the spot (with a full 30 day home trial). I think they're great and not just for the price. I still have my tube and solid state Class A amps. I still listen to those when the mood strikes (and it's really cold outside).