[Freo-1]

I'm curious as to why there is not more digital amplifiers for high res playback?  I recently obtained a Sony STR-DA7100ES, and the sound from this unit with i-link or HMDI for true multi channel 24 bit playback is outstanding.  This topology seems like the way to go, and yet Sony stopped supporting it 

Pioneer Elite SC-09 and Yahama RX-Z11 both support this type of amplification, and to me, it makes sense to use the amp itself as the D/A converter. 

So, what is going on here?   Has the MP-3 mindset totally ruined hi-res?

PS: Here is some background on what I'm talking about:

 http://www.docs.sony.com/release/ES_STR_05_Final.pdf

[JDUBS]

I used to use the coax input on a Sony STR-DA2000ES and thought it sounded nice.  Could have used some more power, but I do remember it being very smooth.

-Jim

[*Scotty*]

True digital amplifiers as opposed to switching amplifiers have no way to correct errors at their output and the speaker load they are connected to can affect how much distortion they produce. Their distortion characteristics have to be controlled via their power supply. This is difficult and expensive to do. The TACT amplifiers are a good example of perhaps the best implementation of the required measures necessary to produce a High End product. The TACT amplifiers have roughly five time less distortion than the Sony STR-DA2000ES. This is not to say that the SONY sounds bad but the TACT amp should have a more transparent window into the performance everything else being equal.
Scotty

[ted_b]

Digital amplifiers have little to do with what is played as the source.  The digital topology can be varied, such as Class D (Class T, Equabit, Spectron, ICEPower, etc.), Delta-sigma modulation, etc.  Just because an amp is digital (like my wonderful Spectron Musician III Mark 2 monoblocks) doesn't mean they are either suited better or worse for hirez.  I know some of the best hirez systems being amplified by tubes.

[AmpDesigner333]

True digital amplifiers as opposed to switching amplifiers have no way to correct errors at their output and the speaker load they are connected to can affect how much distortion they produce. Their distortion characteristics have to be controlled via their power supply. This is difficult and expensive to do. The TACT amplifiers are a good example of perhaps the best implementation of the required measures necessary to produce a High End product. The TACT amplifiers have roughly five time less distortion than the Sony STR-DA2000ES. This is not to say that the SONY sounds bad but the TACT amp should have a more transparent window into the performance everything else being equal.
Scotty

Scotty,

"True digital amps" CAN have feedback, and thus correct for errors.  Imagine an amp that takes a digital input and converts the analog output back to digital.  I have a patent on this.  Just my 2 cents...

Also, regarding other switching amp technologies, such as "Class-T", ANY amplifier that uses its output devices as switches is really Class-D.  All the fake class names are just marketing tricks.

Amplifiers that modulate PWM and drive an output stage open loop are nothing new (circa 1990s).  Another few patents I authored were bought by ST Micro and used in their chips.  That stuff was developed back in the mid to late 90s and couldn't deliver the performance that analog feedback can.  Also, clocked systems by nature don't offer the resolution that continuous-time systems can, such as used in the DAC4800A and Cherry amps we sell.  After decades of work on D/A and A/D conversion techniques, power circuit design, and signal processing, the truth remains...  The proof is in the pudding!  Thanks for your thought on this.

Best Regards,
Tommy

[Freo-1]

True digital amplifiers as opposed to switching amplifiers have no way to correct errors at their output and the speaker load they are connected to can affect how much distortion they produce. Their distortion characteristics have to be controlled via their power supply. This is difficult and expensive to do. The TACT amplifiers are a good example of perhaps the best implementation of the required measures necessary to produce a High End product. The TACT amplifiers have roughly five time less distortion than the Sony STR-DA2000ES. This is not to say that the SONY sounds bad but the TACT amp should have a more transparent window into the performance everything else being equal.
Scotty

The Sony DA7100ES is much better sonically than the 2000 for a whole host of reasons as listed in the reference link at the start of this thread.

The 7100ES via i-link is one of the most transparent sound stages you will ever hear.  Having the bitstream clocked out of the HATS buffer directly to the output MOS-FET's is a great concept.

Check out this review:

http://www.avguide.com/review/sony-str-da7100es-audiovideo-receiver


The distortion argument is interesting.  Sony claims that the S-Master pro setup actually achieves less overall distortion in actual listening than a conventional output amp.  Having listened to this for awhile, I think there is a fair bit of truth to this.

I would like to listen to a Elite SC-09 sometime to compare.   

[cloudbaseracer]

I'm curious as to why there is not more digital amplifiers for high res playback?  I recently obtained a Sony STR-DA7100ES, and the sound from this unit with i-link or HMDI for true multi channel 24 bit playback is outstanding.  This topology seems like the way to go, and yet Sony stopped supporting it 

Pioneer Elite SC-09 and Yahama RX-Z11 both support this type of amplification, and to me, it makes sense to use the amp itself as the D/A converter. 

So, what is going on here?   Has the MP-3 mindset totally ruined hi-res?

PS: Here is some background on what I'm talking about:

 http://www.docs.sony.com/release/ES_STR_05_Final.pdf

I too am extremely interested the ALL DIGITAL pathway.  I currently run the Panasonic amps using the Texas Instruments Equibit chip.  I kn ow the Tact uses this same chipset but not sure of any others.

I have been doing a lot of research lately and have come across:

NAD

http://nadelectronics.com/products/masters-series/M2-Direct-Digital-Amplifier

http://www.diodes.com/zetex/_pdfs/literature/pdf/SCCLZBR2.pdf

Behold -- PCM into PWM

http://www.behold.eu/page.php?en321100

http://www.avguide.com/blog/upper-end-preamps-and-amps-rocky-mountain


I am no expert by any means but most people associate Class D with digital and they are simply not the same thing.  The ICE, Hypex etc all amplify in the analog domain as far as I understand.  This is a major difference in my book.  Of course the proof is in the sound and many people have been highly impressed with the Equibit sound in the Panasonic.  Seems like the Sony product is pretty good as well.

Are the Cherry Amps actually fully digital? 

James

[Regalma]

I am curious as to what the definition of digital amplifier is. I class D and others like that are not digital. The coincidence between D and Digital is unfortunate.

It seems to me that no matter what, the amp output has to end up being analog because speakers, not to mention our ears, are analog.

Anyway, I am curious as to what people define as digital amplification.