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. 


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.


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.