Digital input amp

They take a USB or other input. No DAC on the front end. Just the DSP engine to do volume, eq, etc, then whatever conversion to PCM to feed the class D output. So the only "DAC" is the output stage. 

@tvrgeek To be clear, the DAC is at the input of the amp, not the output. Class D is not digital since the switching of the amp does not have meaning whereas the switching of a digital word does. So you have to convert from the latter to the former.

Not these designs.  They take a bitstream , do DSP, do the digital conversion to PWM and feed the output. So the actual integrator and filter is the output.  There is no DAC on their input. 

Maybe you should look at the block diagram of these products.  They take digital in. Process within a DCP chip which produces the PWM signal to feed the output.  

atmasphere

I know a lot of companies say they have a 'digital amp' but if they also say its class D then the DAC is always at the input to the class D circuitry.

That's what I always thought. Thanks for confirming, Ralph.

This technology HAS NO DAC. Please go look at the products. Look at the Peachtree GAN1 as well as the Sabaj.   I think NAD has one with built in streamer. 

PCM in. Convert to PWM. Switch outputs.  Integrate.   NO DAC. 

I don;t know what other companies are advertising. The copy writers may not have a clue either. 

OP:

Exactly how are you defining a DAC? From your description, the amp IS A DAC.

Simply put, a DAC stands for digital to analog converter. You don’t listen to PWM. You listen to, must listen to, music as an analog event.

So that PWM signal must go somewhere, and the moment it becomes an analog signal you have a DAC.

I should also point out that Class D is an analog, but switched system. A purely PWM driven amplifier has complications of it’s own, especially how the lack of feedback is a challenge.

To borrow a term from marketters, this is a powerDAC.

Want to add a little:

Class D is a switched output amp but the switching is completely controlled in the analog domain.

Modern amps like Technics may be called a digital amplifier in the sense that it is a digital process controlling the switching of the output duty cycle, but it IS a DAC. Further, these digital amplifiers (as I define here) have challenges in properly implementing a feedback circuit.  Technics famously gets around their issues with a calibration cycle.

Love it when a guy comes on here (@tvrgeek) and corrects a person with more experience in designing and building amplifiers than anyone here. Node has a DAC...

What is the GaN 1?

It is a 200 watt-per-channel power amplifier designed to be the sole interface between your variable output digital audio device, like a Bluesound NODE, and your speakers. The GaN 1 is a simple, pure and cost-effective audio solution. Connect the GaN 1 to a streamer and a pair of speakers. That's it...no DAC, no preamp and no input switching. The signal path from the music to your speakers is remarkably short and free from artifacts. Do you want to hear the intricate details in your music that have always been there, but you couldn't quite make them out before...but NOT in an analytical or fatiguing way...simply reproduced as naturally and realistically as they were captured? Then the GaN 1 is for you!

DAC is the acronym for "digital to analog converter"

Human cannot hear an unconverted digital signal as music.  It must be converted to analog. Therefore, if you are putting a digital signal into a device and getting an analog signal out of it, it must contain a DAC.

I didn't eat a donut, I am the donut.

Jeff, get off your high horse and READ about how the product works.   

There is no INPUT DAC. 

tvrgeek

... READ about how the product works ...

As you noted earlier:

The copy writers may not have a clue.

The GAN1 (after mods by tweakaudio.com) approaches levels that are shocking for $1200 + 500 mods. Send me a DM if you want to discuss more.

The reason being the nature of the GAN1 design. It is SIMPLE.

Jeff, I was talking about the Gan1 amplifier technology. Not the Bluesound node. I think the streamer has a PCM out so you can bypass the internal DAC.  The reason to use it as a front is to move the volume control to it, get a remote, and a sub out.  I don't give a rat's patutti about Airplay or other low resolution pay as you go garbage and the last thing I would ever have in my house is Alexa. 

The Sabaj has some of these functions built in. It has a larger DSP section than the Peachtree and includes a traditional DAC for sub output. 

FYI, I have designed and built SS, tube and amplifiers. I have a degree in electronics. 

Whatever okay. I will stick to known engineers, designers and builders that have a stellar product line and reputation as my sources of information. Not an unknown commodity as such.  You also seem to be very attracted to cheap, economical products. Are you a regular from ASR? 

  FYI, I have designed and built SS, tube and amplifiers. I have a degree in electronics.

This technology HAS NO DAC.

@tvrgeek If this is so, then the amplifier is not also class D. Class D is a very specific class of operation. Since you apparently have a degree, then you know that class D was proposed in the 1950s and the first home implementations were sold in the 1960s. You also know the building blocks required. So pick one: if its class D then it has a DAC built into the same box to which the digital signal arrives prior to the class D circuitry and probably one the same board as the class D section.

If this is false then its not a class D amplifier inside although it might employ switching technology.

Thank you Ralph. Much like the Gold Note PA-10 that employs switching technology (their version of GaN) and is not Class D as some of the  audio journalists have misstated over the last couple of years (Darko). 

If this is false then its not a class D amplifier inside although it might employ switching technology.

Of course the OUTPUT stage is an integrator. I said so from the beginning.  Gad how some here want to be so superior.  The entire point is this is a new technology worth watching as it changes the entire string. The Peachtree Gan1 does not have a traditional front end DAC.

I also got some comments from the local dealer who has heard this unit and they suggest it is not quite ready for prime tike. 

tvrgeek

... Gad how some here want to be so superior ...

I think users here are just trying to be accurate. You choose to take it personally that your claim has been questioned:

They take a USB or other input. No DAC on the front end. Just the DSP engine to do volume, eq, etc, then whatever conversion to PCM to feed the class D output. So the only "DAC" is the output stage.

Gad my post was deleted, gads I questioned the OP credibility, Gads. 

I tried streaming to the GAN1 using fibre via a Lumin X1 and also a Sonore OpticalRendu. I controlled all of this via ROON. Not simple for someone new to digital but I have a lot of experience with streaming and software.

The GAN1 (modded) with the uber quality streaming I used was amazing.

Look at what Mark Levinson is doing with his new company, Daniel Hertz. This is likely the beginning of some great gear with much less components. Now that is not good for anyone in audio except the consumer.

The STOCK GAN1 is just very good. The mods make it jaw dropping good (as long as the 200-watts are adequate).

Very interested in the mods. I visited a showroom ( dealer for both Peachtree and Bluesound) and their conclusion was neither were quite high end yet and are not carrying those specific products.  They did suggest some of the esoteric amps using the GaNFets were very good. But for mainstream non-exoteric those of us who have to spend real money, the better of the A/B are still winners.  They suggested there are much better streamers than the Blue Node.  That leaves me with a lot to research.  Bits may be bits, but what you do with them matters.  Things seem to move fast though.   I'll look up the D-H stuff. 

This technology makes sense to me from the engineering side. Probably really bad for DAC and preamp makers. If the market is there, we need someone to do an ASIC for the entire front end and then high end will be affordable to the masses.  Low volume, I guess FPLAs.  Hear that, Masimo?  You have the wherewithal to pull it off!  The smartest engineering  Mom and Pops are not going to get the volume needed even if they come up with the breakthrough ideas. Even Bruno has not got there yet. 

From the PA-10 WEB, I could not tell what technology they were using. Some sort of hybrid maybe.  

 I see one here just can't stop insulting people. Sigh.  Nobody can learn anything that way. 

@tvrgeek 

I see one here just can't stop insulting people. Sigh.  Nobody can learn anything that way. 

Actually @tvrgeek, here's a heads up.  Most of us here have a fairly thick skin.  But what would you think about someone who starts a thread and then tells a great designer of amplifiers he does not really understand how an amplifier works?  And then when it is pointed out feels he is insulted?

 @jetter +10,000 Ralph has forgotten more than most will ever know. He is  respected and is a proven source for knowledge, world class amplification and engineering/design. Gads unlike a certain someone. Sigh and he/she has nothing to offer from stand point of teaching and thinks he is the smartest guy in the room, sigh.  

@tvrgeek Lets impart some knowledge on the PA-10.

I’d guessed given the overall sound of the PA-10 that it was in some way Class D in its architecture, but Gold Note makes no mention of this in their technical specifications. Personally, I’m a massive advocate of Class D technology when it is done well and so I asked Gold Note directly “What Class of amplifier is the PA-10?”. Here is the response I got – “ The PA-10 features quite an interesting design. It is not a Class D amplifier but it leverages a new technology that uses MOSFETs for the output stage, in common with the Class D, featuring an output oscillator (GaN Mosfets with Gallium Nitride), a proprietary design that actually doubles the power of the amplifier when reducing the impedance – exactly as a pure Class A but with extremely high efficiency to deliver great amounts of energy.” So there you have it. 

Sad Gold Note only gave marketing BS as a description.  I would love to see an IEEE or AES paper on whatever they are doing to see if it really is innovative. The  bummer is it is within my price, but only direct sales and no audition/return policy I could find. Their published specs are not defined so even though they are not impressive, not knowing the parameters makes them meaningless.  At what power/frequency is .01% distortion?  Is it .0001% half a Watt lower?   Could be a great amp, could be not so.  Totally useless specs. 

"Well executed" does seem to be the issue. I guess my best bet is a Buckeye/Purify based amp. Either that or go the safe rout with a Schiit Vidar.  I have recently heard a Hypex based amp and it is far better than the older ICE amps or the new CH-FI $80 wonders, but not there yet. 

The mentioned Peachtree "digital input amplifier " I started the thread on, maybe some clarification.  Their point is they did not have a DAC on the front end.   Their block diagram, not mine. 

If the specific implementation of using a triangle and an analog signal to generate the PWM control only being class D, then that implementation needs a DAC somewhere along the line before the conversion.  Two DACs if you count the output filter.  That is not what they were saying as they  do the entire processing from PCM to the PWM control in the digital domain.  I would still call it a class D, just a different way to get there. That is what their literature says. 

This is easily summed up -- take sales and marketing literature with more than a grain of salt.

Example -- cigarette companies once used medical doctors in their ads to promote the health benefits of their brand. Advertising execs will spare nothing, perhaps short of lawsuits and jail, in trying to get you to think their product is advanced and unique.

Only way to find out would be to listen to one. Or are you spec sheet jockey?

Totally useless spec like you post I guess. Love these keyboard engineers. Head on back to ASR.

Sad Gold Note only gave marketing BS as a description.  I would love to see an IEEE or AES paper on whatever they are doing to see if it really is innovative. The  bummer is it is within my price, but only direct sales and no audition/return policy I could find. Their published specs are not defined so even though they are not impressive, not knowing the parameters makes them meaningless.  At what power/frequency is .01% distortion?  Is it .0001% half a Watt lower?   Could be a great amp, could be not so.  Totally useless specs. 

 

Guess Google is new to you:

https://goldnoteusa.com/dealer-locator/

Gestalt Audio1637 11th Ave N  Nashville TN 37208USA

Phone: 615-838-7178Email: colin@gestalt.audio

Brooks Berdan Ltd.110 West Olive Ave.Monrovia CA 91016USA

Phone: (626) 359-9131Email: info@brooksberdanltd.com

NEW US DISTRIBUTPOR I BOUGHT FROM THEM.

Analog Matters1453 US 1 North Unit D-32Ormond Beach Fl 32174USA

Phone: 800 752 4018Email: analogmatters1@gmail.com 

Yes, listening is the only way. That is about the only thing we agree on. 

Specs give you a starting point when you can't go to a local store and get at least a quick audition.  But when you ask a company about their product and they respond with BS, that does not give me a warm and fuzzy.  Customer support is something some of these companies need to understand. Heck, even IBM is nice to you before you signed a contract. 

To inform you Jeffery O'l boy with your snarky attitude, The above mentioned dealers do not have audition return policies. I don't live in Ca, Fl or Tn.  Now,  what part of me suggesting it could be great or poor as the specs ( rather poor) are useless did you not understand?

I am not on ASR as I DARED to suggest I could hear the difference between my DACs. That was too much for Amair.  As I understand the specs and how they were measured, I know when they are actually a hint or not. 

PS: I know a little more about Google than you think.  The guy who wrote Acumulo, the Java version of Big Table/H Base, used to work for me.   Just a hint. 

Hmm so you called them all? So cause a guy worked for you makes you an expert, okay. 

So you called them in Italy? Really. Funny they answered all my questions. Guess that is why I am enjoying these amplifiers and you are not. 

Not my fault you live in the boondocks and cant get an audition. Head on over to Best Buy. You can keep living in 1960 if you want.  If you were remotely interested you would have seen Safe and Sound that offer return privilege's:

Returns
Returns are accepted for products purchased within the last 30 days. You must call us to initiate a Return Authorization 800-820-6460.

• You are responsible for return shipping costs.
• Products MUST be in LIKE NEW Resalable condition.
• You MUST have the ORIGINAL BOX and PACKAGING MATERIALS.
• You MUST have all of the original accessories, manuals etc.
• Your package should be INSURED for the FULL VALUE for your protection during return shipping.

Enjoy 1960 Mr Geek! 

Actually, as the Data Systems Architect, Program Manager, and Acquisition Manager, yes I was an expert in extreme scale databases when I retired. Six years later, I am probably an antique. That technology moves faster than SMSL can introduce DACs. 

If you think Gold Note answered your question, you have zero understanding about how an amplifier works no matter how many times you insult me. I do hope they are nice amplifiers, but I will never know. 

"Doubles the power when reducing impedance"   So what. Any good amp can. 

"Switching, but not class D".  OK,  they did not say what it is though.  

"Exactly like class A"   Nope.  Not at all.

"More efficient" Yea, so is class A/B, G, H and D. 

Again, I hope they are very nice. I hope they have some innovation to add, but their marketing BS you quoted does not give any hint and their published specs would not make it on the shelf at Best Buy with the boom-boxes. 

I  just ordered a Schiit Vidar. They have excellent customer service and their web site plainly explains the audition return policy. Their specifications include the test parameters.  For half the price. 

I intentionally live in the boondocks, if you call 1.2 million people in the area the boondocks.  Lots of wildlife in the woods behind me. My camera has snapped coyote, fox, bear, deer, possum, racoon, otter, skunk, owl, hawks, herons, and way too many copperheads. No obnoxious street lights, no kids drag racing up the street at night.  Spread out enough I can crank up my subs without bothering anyone. But only half an hour away from world class medical and a Super Walmart.  I vacationed to DC/Va/Pa recently and hit a few remaining high end stores up there. Kind of like Home Depot, they all have the same generic stuff.  I'll stay down in the Piedmont, thank you. Amazon makes it to my door in a day. 

BTW it was not from Gold Note Specs, read much. Use google much, no bio please yawn. Should read some of the reviews (what I quoted slick) as they are all positive just like the Schiit you purchased. Go to a show or two, get enlightened.

BS you quoted does not give any hint and their published specs 

Passed on the DC show due to COVID. Maybe next year. 

Again, I hope it sounds great, but I'll never know.  I put zero faith in reviews as if they are not glowing, the reviewer never gets anything to review.   More BS. You have no problem suggesting units I have or have heard are junk, but most of them have outstanding reviews.   I have heard a lot of stupid ego priced equipment I would not trade my dirt cheap JDS for. Glowing reviews or not. 

COVID? Come On Man! Are you Howard Stern? No really if your gear sounds good to you then good for you. Gads you are not the end all know it all as Ralph pointed out. Enjoy your JDS.

Thought you ordered a Schiit amplifier or was that just Schiit.

Please do tell me what I have suggested that you have hear (no first hand experience I see) or heard are crap, slick?.  

Actually we have health conditions that put us at high risk.  It is called being smart. 

And yes, I am right now enjoying my JDS while waiting for the FEDX delivery. 

Still did not answer my question.

It's your life you can live it in fear or not. 

Please do tell me what I have suggested that you have hear (no first hand experience I see) or heard are crap, slick?.  

"Doubles the power when reducing impedance"   So what. Any good amp can. 

"Switching, but not class D".  OK,  they did not say what it is though.  

"Exactly like class A"   Nope.  Not at all.

"More efficient" Yea, so is class A/B, G, H and D. 

Again, I hope they are very nice. I hope they have some innovation to add, but their marketing BS you quoted does not give any hint

@tvrgeek I had the same misgivings about that bit from the marketing department. As best I can make out this amp is class T.

@atmasphere Interesting (though that was not marketing, you and @tvrgeek both got that wrong) So class T is not really a class though, and it is really just Class D with  GaN mosfet built in house like your amplifiers. Nice! The PA-10's sound freaking awesome, much better than the Schiit I used to have, you should give them a listen and like your amplifiers the reviews have been very positive. 

https://www.hifipig.com/gold-note-pa-10-power-amplifier/

https://positive-feedback.com/reviews/hardware-reviews/gold-note-pa-10-amplifiers/

https://6moons.com/audioreview_articles/goldnote13/

https://darko.audio/2020/07/brawn-and-brains-gold-notes-pa-10-power-amplifier/

According to Wikipedia, “A Class T amplifier is an audio amplifier IC design. Rather than being a separate “class” of amplifier, Class T is a registered trademark for Tripath’s amplifier technologies. The control signals in Class T amplifiers may be computed using digital signal processing or fully analog techniques.” The page then goes into detail but I’ll not quote all that here. So, it seems that most switching amps are class D, some are erroneously called class T and some really are class T.

I’d guessed given the overall sound of the PA-10 that it was in some way Class D in its architecture, but Gold Note makes no mention of this in their technical specifications. Personally, I’m a massive advocate of Class D technology when it is done well and so I asked Gold Note directly “What Class of amplifier is the PA-10?”. Here is the response I got – “ The PA-10 features quite an interesting design. It is not a Class D amplifier but it leverages a new technology that uses MOSFETs for the output stage, in common with the Class D, featuring an output oscillator (GaN Mosfets with Gallium Nitride), a proprietary design that actually doubles the power of the amplifier when reducing the impedance – exactly as a pure Class A but with extremely high efficiency to deliver great amounts of energy.” So there you have it.

@jeffrey125 Thanks for the correction- I knew that once upon a time...

@atmasphere You have forgotten more than I will ever know.