Digital input amp


I see a few coming on market.  Previous threads were quite old.

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.   This makes sense as it further reduces the functions in the chain.  I have not seen objective testing or any reliable subjective testing. The ones I have seen are Infineon processer based. No idea if the output filtering or feedback implementation is up to the Purify quality.   I guess the next innovation is the GaNFET output.  One has a DAC to feed a sub out. Easy as any old $5 DAC will wo there. 

I was browsing and came across the Sajab A30a. ( quite inexpensive)  Peachtree has the old Gan-1 but coax PCM only.  That would be fine if it managed buffering and clocks internally. Unfortunately my all-in-one only has USB out. 

I suspect there is a lot to be learned here but it makes sense to me for the future. 

tvrgeek

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

Phone615-838-7178Emailcolin@gestalt.audio

 

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

Phone(626) 359-9131Emailinfo@brooksberdanltd.com

NEW US DISTRIBUTPOR I BOUGHT FROM THEM.

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

Phone800 752 4018Emailanalogmatters1@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.