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List of Digital (Class-D) Home Theater Receivers - Page 60

post #1771 of 1899
Quote:
Originally Posted by drawz View Post

1. The board is listed as C500/C700, implying it's the same PCB at least. I'm sure there are differences in the components used.

Hmmm... eagle eyes

Quote:
Originally Posted by drawz View Post

2. There are some IR (International Rectifier) chips near that Pulsus chip. IR makes a number of ICs for class-d amplification. I wonder if you could give us the model #'s of those chips - I can't quite read them in the pics. Perhaps IR is involved in the Pulsus class-d amp solution?

Which one ? on photo # 6 ?
post #1772 of 1899
Nothing gets past me

Actually see a couple chips with their logo in 5 & 6.

Quote:
Originally Posted by CowoJawa View Post

Hmmm... eagle eyes

Which one ? on photo # 6 ?
post #1773 of 1899
Quote:
Originally Posted by drawz View Post

Nothing gets past me

Actually see a couple chips with their logo in 5 & 6.

Crop from original # 6

post #1774 of 1899
Quote:
Originally Posted by CowoJawa View Post

Crop from original # 6


Interesting - the IRS2092 is an analog input class-d amp driver from International Rectifier. It can be scaled from 50 to 500W into 4 ohms, depending on the supporting chips of course.
I don't see the IRS2053M on the web, but I didn't look very hard. Based on the topology, I would speculate that it provides the amp driver for 3 (?) of the channels. Since there are two of them, that's 6 channels with the 7th driven by the IRS2092.
post #1775 of 1899
Quote:
Originally Posted by drawz View Post

Interesting - the IRS2092 is an analog input class-d amp driver from International Rectifier. It can be scaled from 50 to 500W into 4 ohms, depending on the supporting chips of course.
I don't see the IRS2053M on the web, but I didn't look very hard. Based on the topology, I would speculate that it provides the amp driver for 3 (?) of the channels. Since there are two of them, that's 6 channels with the 7th driven by the IRS2092.

Whats really comical about this design is that previous pics were used as a basis for argument about how great this "pure digital" design was when its anything but "pure digital".

The Pulsus PS9830D is doing some basic DSP/signal processing work then outputing up to 11 channels of PWM. Probably 7.1 + stereo + headphones or something like that.

The channels to be amplified are fed over to the AUK S4580 dual op amps (SOIC8 packages x 4) which take the PWM out of the Pulsus IC and filter it down to analog audio.

Effectively the Pulsus IC is acting as a 1 bit DAC and the op amps acting as reconstruction filters.

The analog audio is then sent into the IRS2095M Class D drivers which takes the analog audio and turns it into a PWM representation with proper dead time, etc for the driving the MOSFET's which are under the long heatsink. Whats interesting is that we can see that the power supply is providing + and - PVDD so the output stage is running a half bridge configuration. This does mean that there could be negative feedback into the single op amp filter applied by the S4580. That would definitely be a boost for audio performance and explain the choice to convert to analog instead of using a PWM input class D driver.

The SOIC-N16 in the middle is the IRS2092S which is a single channel analog input class D driver. The others are 3 channel by the looks so i would assume there are 7 channels available in this design.

The NEC D78F1166A over in the middle is a 16bit microcontroller, its probably there to run the front screen, handle buttons, and tell all the other IC's that are doing the processing what to do.

The AK4115VF is the S/PDIF sampling rate converter and the AK5367 next to it is an ADC (i've used AK ADC's in designs before, decent units especially because they are super cheap) Not sure what its doing there, all the other ADCs are over above the TI DSP.

Pretty standard design for a low cost receiver. Some of the part choices are odd. The NEC uC is a pretty wacky thing, didn't honestly know they still made their own uC cores. However they probably have been using them for a long time and wanted to reuse the code. I'm actually pretty sure Renesas bought out their uC business.

I'd really like to see the part numbers on the IC's attached to the heatsinks in the power supply. It looks like its either a very low power linear supply or that its unregulated for the amp section. In which case its just using the input power transformer to step down to the desired voltage then the parts on the heat sinks are half bridge rectifiers to produce +/- PVDD. Unregulated is pretty scary for a class D design as the amp gain is tied directly to the rail voltage, any change in rail voltage will have a direct effect on amp gain. The fact that its labeled on the board as +/- PVDD rather than an actual voltage as all other rails are may support the idea that its unregulated.

The lower right hand side is almost certain linear regulation or the digital supplys. +12,+5,+3.3 probably.
post #1776 of 1899
Quote:
Originally Posted by xianthax View Post

Whats really comical about this design is that previous pics were used as a basis for argument about how great this "pure digital" design was when its anything but "pure digital".

The Pulsus PS9830D is doing some basic DSP/signal processing work then outputing up to 11 channels of PWM. Probably 7.1 + stereo + headphones or something like that.

The channels to be amplified are fed over to the AUK S4580 dual op amps (SOIC8 packages x 4) which take the PWM out of the Pulsus IC and filter it down to analog audio.

Effectively the Pulsus IC is acting as a 1 bit DAC and the op amps acting as reconstruction filters.

The analog audio is then sent into the IRS2095M Class D drivers which takes the analog audio and turns it into a PWM representation with proper dead time, etc for the driving the MOSFET's which are under the long heatsink. Whats interesting is that we can see that the power supply is providing + and - PVDD so the output stage is running a half bridge configuration. This does mean that there could be negative feedback into the single op amp filter applied by the S4580. That would definitely be a boost for audio performance and explain the choice to convert to analog instead of using a PWM input class D driver.

The SOIC-N16 in the middle is the IRS2092S which is a single channel analog input class D driver. The others are 3 channel by the looks so i would assume there are 7 channels available in this design.

The NEC D78F1166A over in the middle is a 16bit microcontroller, its probably there to run the front screen, handle buttons, and tell all the other IC's that are doing the processing what to do.

The AK4115VF is the S/PDIF sampling rate converter and the AK5367 next to it is an ADC (i've used AK ADC's in designs before, decent units especially because they are super cheap) Not sure what its doing there, all the other ADCs are over above the TI DSP.

Pretty standard design for a low cost receiver. Some of the part choices are odd. The NEC uC is a pretty wacky thing, didn't honestly know they still made their own uC cores. However they probably have been using them for a long time and wanted to reuse the code. I'm actually pretty sure Renesas bought out their uC business.

I'd really like to see the part numbers on the IC's attached to the heatsinks in the power supply. It looks like its either a very low power linear supply or that its unregulated for the amp section. In which case its just using the input power transformer to step down to the desired voltage then the parts on the heat sinks are half bridge rectifiers to produce +/- PVDD. Unregulated is pretty scary for a class D design as the amp gain is tied directly to the rail voltage, any change in rail voltage will have a direct effect on amp gain. The fact that its labeled on the board as +/- PVDD rather than an actual voltage as all other rails are may support the idea that its unregulated.

The lower right hand side is almost certain linear regulation or the digital supplys. +12,+5,+3.3 probably.

Great analysis xianthax! Really appreciate it.

DIY amp modules based on the IRS2092S are considered to be quite good, but they're of course built with relatively high quality parts. If by some off chance Samsung used quality parts and proper board layout in their build, this could be a pretty good amp section for a budget receiver. Your concerns about the power supply are well taken. I wonder if a power supply replacement could be a major upgrade here? Perhaps with a high quality SMPS intended for audio amplifiers? If we knew the part number of the MOSFETs under the ICs, we could get a better idea of the true potential power output of this thing (barring power supply limitations).
post #1777 of 1899
I own one of these Samsung amplifiers. I think the forum might be criticizing it too harshly. I bought mine for $250, which - at that range - amplifiers do not have 7.1, or do not have decode support for HDMI audio, or do not have 7.1 analog inputs (I have lots of SACD surround discs), or won't send a signal to the subwoofer in stereo mode (forcing the listener to use one of the DSP modes in order to actually get sound out of the sub), and so on. For $250, the Samsung has a very strong feature list - at least as good as its competition.

It also sounds very good. It delivers more detail, more transient power than the aging Sony amp it replaced. This is hard to define - but the different-ness of mastering and mixing techniques is more apparent than with my previous amp. Is it important to me how many chips are between the signal and my speakers? Since I am a listener and not a designer - no. But the Samsung, as a bargain-value amplifier, has really hit it out of the park for me. Whether it deserves to be included in a list of amplifiers with an un-messed-around-with digital topology is a question that I'm not qualified to answer. But for the price, I doubt I could have found something else to meet my needs. I've been trying for over a year to find that mix of features for under $300.
post #1778 of 1899
Quote:
Originally Posted by morphon View Post

I own one of these Samsung amplifiers. I think the forum might be criticizing it too harshly.

I should clarify, theres nothing terribly bad about the design, especially at its price point. I question how they passed signals over that split ground without EMI issues, but i'd have to see the full PCB design to figure that out. It obviously passed FCC part 15 so they handled it somehow.

I very, very much doubt it can provide its rated power with all, or maybe more than 1 channel driven. But for its target market, low-mid end home theater, that probably doesn't matter. Few people use more than a few watts if that for surrounds. Heck even mains unless your trying to listen at reference.

It also probably has some bus pumping issues due to the power supply design and lack of feedback from the rails. This would result in poor frequency response during high power situations. But those are only really exacerbated at low frequencies. Its doubtful that many that purchase true full range speakers would spend $250 on a receiver as their speakers usually cost 2+ times that amount a piece.

So there is nothing in the design that would say it would be a bad performing product for its intended market.

My rather attackish critque of the design is a result of this thread which was trying to assert that this thing was the most amazing product ever built, with state of the art technology, etc. Claims were made all over the place, "pure digital, analog", "no EMI", blah, blah.

All marketing rubish. This is a standard, analog input, class D design which likely has basic negative feedback. Which is fine. But nothing "amazing". Its same type of full range class D design that has been around for like a decade.
post #1779 of 1899
Quote:
Originally Posted by xianthax View Post

Guessing with no listening

First you assume too many things and are guessing.
A lot of the chips are for the 7.1 analog inputs. Who cares?

Samsung and Pulsus are notorious for keeping their technology secret. You really need to research the patents for better insight. The fact is you are taking an educated guess at best, based upon older technology.

Those Who Listen
---------------
Member Morphon hears the difference:
"It also sounds very good. It delivers more detail, more transient power than the aging Sony amp it replaced. This is hard to define - but the different-ness of mastering and mixing techniques is more apparent than with my previous amp."

I'll add: the pin-point imaging and holographic depth are remarkable with no edginess whatsoever.

The "secret sauce" is in the chips/IC/DSP. I've read some of the DTS patents listed on the back and the audio processing is quite advanced. I don't think the elaborate MSB/LSB processing is just for decoding of DTS input signals either.

There is no conventional D/A converter. Or volume control. My hunch is the volume is scaled in the PCM to PWM converter. The amplifiers basic frequency is scaled too, which differs from other class D designs.
All this is most certainly not standard fare. The design is a break through in sonic realism. Further by reducing the expensive parts the price and power consumption is reduced..

The difference is I'm ignorant and know it. But for $299 (at BB this week) its a no-brainier to audition. The new level of sound quality is something to behold.

My enthusiasm for the HW-C700B extraordinary sound quality must be making waves as Home Theater Magazine just published a scathing attack on the expensive Rotel ICE amplifiers in their November 2010 issue. I've never seen anything like it!

My analysis is the high-end industry (with good justification) feels threatened by the new generation of inexpensive commodity priced Pulsus amplifiers (many companies have already taken out licenses). So paint with a broad-bush and prepare for battle! Its all about the money.

The British smear it too:
http://www.whathifi.com/Review/Samsung-HW-C700/

Don't threaten my livelihood dude!

But the dutch offer a new clue
Dutch to English translation
Finally, a home theater system that sounds just as important as the image. The Samsung HT C7500. Normal home theater systems rely on digital amps and tend to produce a mediocre sound. However, the HT C7500 uses unique, patented, high-performance Crystal Amp Pro technology to a world of incredibly pure sound. The sound quality is greatly enhanced by multi-variable feedback signals, surpassing the average of normal-sounding audio systems.

Notice how easily duped the average consumer is (but a select few are able figure out something extraordinary):
http://www.amazon.com/Samsung-HW-C70...DateDescending

Here is another smear campaign:
http://forums.audioholics.com/forums...ad.php?t=67673

Oh wait Newegg customers show the most sophistication. Were actually going positive. Whowhoooo!
http://www.newegg.com/Product/Produc...82E16882676164
$199 no tax or shipping

Some more competent people who actually listen:
http://www.samsung.com/us/video/home...00/XAA-reviews


Please install the firmware update!
post #1780 of 1899
Quote:
Originally Posted by HiFiFun View Post

First you assume too many things and are guessing.
A lot of the chips are for the 7.1 analog inputs. Who cares?

Nothing i noted was for the 7.1 analog in, those are the ADCs over above the TI DSP.

Quote:
Originally Posted by HiFiFun View Post

Samsung and Pulsus are notorious for keeping their technology secret. You really need to research the patents for better insight. The fact is you are taking an educated guess at best, based upon older technology.

1) this not a single Samsung ASIC anywhere in this design so i have no idea what "technology" they would be keeping secret.

2) heres the block diagram/pin out for the Pulsus PS9830B, its not very secret:



3) Here is the data sheet for one of the actually class D amplifier controllers, note that in this design the pulsus IC is just doing some light DSP work and operating as a DAC, it has nothing to do with the amplification section.

4) Here are specifications from the Samsung Manual:

Rated output 20Hz~20kHz/THD = 0.9%, 6 Ω 120W/CH

Input sensitivity/impedance 450mV/47kΩ
S/N ratio (analog input) 80dB
Separation (1kHz) 60dB

Analog input 20Hz~20kHz(±3dB)
Digital input/96kHz PCM 20Hz ~44kHz(±3dB)

Curiously it also lists the total power consumption for the units at 75W which is well....odd....but i can't say i don't believe it based on the power supply.

So again, in summary, this receiver uses nothing new in its amplifier section at all, its using a very standard analog input class D topology that been around for a very long time, unless you have some actual measurements that contradict their own listed specifications, i will also assume its audio performance is quite bad in comparison to anything in the "high" or even "mid" range.
post #1781 of 1899
I suggested to research the Pulsus patents. Instead you post anonymous vague block diagrams! There is zero credibility here as any Pulsus/Samsung innovation is contained in the only block with unreadable text!

After much listening I am now able to definitively describe the gains in Pulsu/Samsung sound quality and their reasons why.
First, anyone with a good system setup (many still are not), can hear what I'm hearing. There is a clearer delineation of each track in the mix, like never before. Take for instance the Beatles 24 bit thumb drive release in FLAC format.
One can better hear John and Paul harmonizing and their overdubs. better soundstaging with precise pinpoint imaging between all the speakers.
Even the best digital to analog stages have a certain false heaviness and in-articulation to the bass and vocals which no-doubt drive many to expensive room correction processing (them 2K receivers).

Here is one major technical reason what the astute listener is noticing:
For the first time there is no D/A conversion - and most importantly - the resulting analog signal is not amplified the typical 28db afterwards.

Instead the amplifiers output stage gain is driven/shaped digitally so any errors are not amplified. This is a huge 28 db difference!

No one really has even discussed how audible the effects of the D/A conversion process really are. Why? (because they have ALWAYS been a necessary evil).

It is common practice to keep digital and analog sections separated both electrically and physically, even with separate power supplies.

However integrated D/A circuits are the big exception. Today all eight channels are combined into one inexpensive chip, even in high-end gear.

After hearing the Samsung 700 receiver, it's obvious we all have been hearing many secondary effects (like high-speed switching and glitches) in modern D/A converters, every since the dawn of digital audio in 1981.

This, dear friends explains why I'm so enthusiastic, as elimination of the line level D/A converter is the biggest breakthrough in my 29 years of listening.

That anyone can buy seven channels of 120 watts, HDMI 1.4 with 3d processing for $199 (no tax and free shipping) is beyond belief. The lesson here for myself is The World is either deceptive or clueless. This system will use all means to oppose consumers from achieving satisfying and extraordinary musical sound quality at beer-budget prices.

File under: Digital Sound finally becomes perfect sound forever.
post #1782 of 1899
Technology wise here is the nearest competitor to the Pulsus/Samsung digital technology:

T-2- New digital Integrated amplifier by Tact

"Tact True Digital Amplification, the sound of the future. The Tact Millennium is recognized as the first true digital audio amplifier. Other so- called Digital or Class D amplifiers have been various combinations of Analog and Digital technology, in most cases using analog feedback. TacT's True Digital Amplification is conceptually different from any other amplification in almost every area of design. Once you understand the fundamental differences you will realize that Tact's complete line of True Digital Amplifiers offer the potential of much higher fidelity than any other digital or analog design.
Having said all of this it is worth pointing out, that the Tact's True Digital Amplifiers are not amplifiers at all. They are D/A converters that just happen to put out enough current and voltage to drive speakers directly, without the need of any amplification. This way it will perform the functions of: D/A converter, Preamplifier and Power Amplifier, without having any analog circuitry after D/A conversion other than one coil and one capacitor performing a 60 kHz, 2nd order low-pass filter.
Essentially, the hundreds of active and passive components usually required for amplification are gone!"

http://www.tactlab.com/Products/T2/T2.html

After making a feature vs. price comparison, I'm all the more grateful for the Pulsus/Samsung's True Digital Amplification leadership. Move over Tact!
post #1783 of 1899
Home Theater Magazine thinks the overweight, obsolete analog receivers are harming the industry. "Desirable features are sometimes trapped in AVRs that are too big, too bulky, or too complicated for some consumers":


Enter Denon's first receiver with digital amplifiers (a monumental change in Denon strategy, but only mentioned in passing in the HT review), measures in at a rather pathetic 28.5 watts. "At $1,799, it’s more expensive than an entry-level (or even midrange) AVR and Blu-ray player combined."

http://hometheatermag.com/receivers/...-ray_receiver/

The review also omits this important point from Australia:
"For stereo playback in particular, the S-5BD features the newly-developed 2-channel Dynamic Play Mode that automatically uses the amplifiers of 4 channels to drive the 2 front channels."
http://www.digitalcinema.com.au/Deno...1-receiver.htm

This feature is actually a tactful admission that these Denon digital amplifiers are too weak and cannot compete against Samsung/Pulsus.

Further confirmation comes from the English TechRadar site:
"The explosions as the Tree Home is destroyed are conveyed with convincing excitement and presence, but this is not a system to worry your foundations. The ultimate power is limited and the sound hardens quickly if you get enthused with the volume knob."
post #1784 of 1899
Good god your still on this?

The Samsung HW-C700 is not an all digital design.

Samsung has no responsibility for the amp technology. The actually class D controllers in that design are from International Rectifier and are standard analog input class D PWM controllers.


On to actual digital feedback amps. That Tact looks interesting, given their history of working with Zetex for Class-D/T controllers i wouldn't be surprised if they are using the same Zetex DDFA chipset in this new amp that NAD used in the M2. If so it should be a very well performing amp.

On the Denon front what makes you think that unit is "all digital" looks like any of the numerous other under powered off the shelf class D amps out there, like the one in the samsung HW-C700 actually
post #1785 of 1899
In the December 2010 issue of Home Theater Magazine the Pioneer Elite SC-37 is reviewed. We read of the major weakness of almost all class D amplifier designs:
"Like class D amps in general, ICE-power converts an analog signal into a train of pulses with rapidly switching output devices..."

Why does ICE DIGITAL require an ANALOG signal?
In other words, since todays signal sources are digital, why is it necessary to convert these digital signal to analog just to drive a "digital" amplifier?

Why not just drive the digital amplifier with a digital signal???
This approach has many benefits!
1) Superior sound quality: no corrupting of delicate analog signals in a noisy digital environment
2) eliminates the traditional D/A converter
3) simplified path
4) lower cost
5) lower weight
6) less components
7) firmware updates for the amplifier

Anyone with an IQ of over 100, would then want to combine this all digital amplifier with an inexpensive and lightweight digital power supply. These high frequency power supplies react much faster and do improve dynamic performance in a true all-digital amplifier.

This combination is what separates the Samsung/Pulsus products from the competition, and makes it the best and the least expensive high-end receiver.

I hope my fellow Americans won't be the last people on Earth to realize the advantages of this Korean university developed technology. To anyone without a vested interest, it should be a no-brainer.
post #1786 of 1899
To achieve the best sound quality class D amplifiers must be all digital:
Here The Absolute Sound reviews the $6000 NAD Master Class D amplifier:

"Functionally, the M2 is an “integrated amplifier” that replaces a DAC, preamplifier, and power amplifier. The M2 eliminates from a traditional signal path all the electronics of a DAC as well as the active analog gain stages of a preamplifier and power amplifier. It does this by converting the PCM signal from a digital source directly into a pulse-width modulation (PWM) signal that turns the M2’s output transistors on and off. That’s it—no digital filter, no DACs, no multiple stages of analog amplification, no interconnects, no jacks, no analog volume control, no preamp. The conversion from the digital domain to the analog domain occurs as a by-product of the switching output stage and its analog filter. This is as direct a signal path as one could envision. (See sidebars for the technical details.)

But in the M2, PCM digital signals fed to the amplifier’s input (from a CD transport, music server, or other source) stay in the digital domain and are converted by digital-signal processing (DSP) to the pulse-width modulated signal that drives the output transistors.

This difference might not seem that great at first glance, but consider the signal path of a conventional digital-playback chain driving a switching power amplifier. In your CD player, data read from the disc go through a digital filter and are converted to analog with a DAC; the DAC’s current output is converted to a voltage with a current-to-voltage converter; the signal is low-pass filtered and then amplified/buffered in the CD player’s analog-output stage. This analog output signal travels down interconnects to a preamplifier with its several stages of amplification, volume control, and output buffer. The preamp’s output then travels down another pair of interconnects to the power amplifier, which typically employs an input stage, a driver stage, and the switching output stage. In addition to the D/A conversion, that’s typically six or seven active amplification stages before the signal gets to the power amplifier’s output stage.

To reiterate the contrast with the M2, PCM data are converted by DSP into the pulse-width modulation signal that drives the output transistors. That’s it. There are no analog gain stages between the PCM data and your loudspeakers. The signal stays in the digital domain until the switching output stage, which, by its nature, acts as a digital-to-analog converter in concert with the output filter. The volume is adjusted in DSP."

This is all SOTA wonderful technology, but at the usual price premium. Two channels for $6K! Compare that to the similar technology in the Samsung 700 receiver.

Note: I've only described the sound quality of the Samsung 700, but the HDMI 1.4 picture quality is razor sharp and natural (the secret sauce in Samsung displays). The video quality matches the audio.

http://www.avguide.com/review/nad-m2...lifier-tas-198
post #1787 of 1899
You literally have no idea what you are talking about, actually zero technical knowledge.

Quote:
Originally Posted by HiFiFun View Post

In the December 2010 issue of Home Theater Magazine the Pioneer Elite SC-37 is reviewed. We read of the major weakness of almost all class D amplifier designs:
"Like class D amps in general, ICE-power converts an analog signal into a train of pulses with rapidly switching output devices..."

Why does ICE DIGITAL require an ANALOG signal?
In other words, since todays signal sources are digital, why is it necessary to convert these digital signal to analog just to drive a "digital" amplifier?

Why not just drive the digital amplifier with a digital signal???
This approach has many benefits!
1) Superior sound quality: no corrupting of delicate analog signals in a noisy digital environment

This is a non-issue if the designer has done his job correctly.

Quote:
Originally Posted by HiFiFun View Post

2) eliminates the traditional D/A converter

A digitally controlled Class D amp is a D/A converter.

Quote:
Originally Posted by HiFiFun View Post

3) simplified path

Not really true, you still require feedback paths and those paths now need to feed into a controller instead of an analog op amp based input filter.

Quote:
Originally Posted by HiFiFun View Post

4) lower cost

Not true for the same level of performance (today). Not being able to introduce negative feedback to an analog input means you need to provide feedback digitally to the controller. You replace a couple op-amps with a DSP, which is not generally a cost win.

Quote:
Originally Posted by HiFiFun View Post

5) lower weight

No idea what makes you think this is true.

Quote:
Originally Posted by HiFiFun View Post

6) less components

Probably not. You replace some op amp input filters with a large DSP based controller which requires about the same number of external components, bypass caps, etc.

Quote:
Originally Posted by HiFiFun View Post

7) firmware updates for the amplifier

Not sure what the digital input to a class D amp has to do with this. Almost all methods of doing digital audio to PWM conversion is built in the ASIC, its not programmable.

Quote:
Originally Posted by HiFiFun View Post

Anyone with an IQ of over 100, would then want to combine this all digital amplifier with an inexpensive and lightweight digital power supply. These high frequency power supplies react much faster and do improve dynamic performance in a true all-digital amplifier.

Throwing bricks in glass houses and all that. Also what on earth do you mean about "high frequency supplies react much faster" i really don't think you understand how a switching mode power supply works in comparison to a linear regulator.

Quote:
Originally Posted by HiFiFun View Post

This combination is what separates the Samsung/Pulsus products from the competition, and makes it the best and the least expensive high-end receiver.

For the 5,000th time, its not even an all digital amp section! The pulsus IC in that design isn't even involved in the class D section!

Quote:
Originally Posted by HiFiFun View Post

I hope my fellow Americans won't be the last people on Earth to realize the advantages of this Korean university developed technology. To anyone without a vested interest, it should be a no-brainer.

Speaking of vested interest, how much Samsung stock do you own?
post #1788 of 1899
Newegg- Samsung HW-C700 7.2-Channel Receiver -"Deactivated. This item is currently out of stock and it may or may not be restocked."
post #1789 of 1899
You don't need to wait until Black Friday to get the good deals. For example Newegg has been selling the top rated Samsung 2TB 3-platter drive for $80. The sales come and go.
I searched for the Samsung 700 receiver and found it for as little as $249, but it was sold out there too.
Big Box had/has them on sale at $299 which allows for return privileges.

I'd like to highlight the subjective observations when so many stages are removed from the signal/processing path. Please read Robert Harley's excellent review of the of the NAD M2 all digital amplifier, as the sonic attributes also apply to the Samsung receiver. You hear greater resolution and tonality of real music. The Samsung sound best playing loud since the peaks are totally uncongested. Bass takes on a whole new clarity and definition. The warm analog bloat/mud is absent.

The fact is every analog stage adds noise and distortion in addition to other colorations. They only become obvious once they are removed. There is a transition period as your ear/brain system adapts to not having to listen to the lifelong irritations.
It's like changing to a prescription with much less side effects. Give yourself time any enjoy the sound of music.
post #1790 of 1899
Quote:
Originally Posted by HiFiFun View Post

Please read Robert Harley's excellent review of the of the NAD M2 all digital amplifier, as the sonic attributes also apply to the Samsung receiver.

Those 2 designs have nothing in common at all.
post #1791 of 1899
I too was beguiled by the seeming elegance of many of today's Class D solutions where the signal remained in the digital domain from source to output filter. This pollyanna notion was quashed several years ago when I attended an AES LA Chapter meeting hosted by noted audio educator John Vanderkooy. Vanderkooy pointed out that the analog to PWM conversion was lossless while the PCM to PWM conversion was not. Another myth shattered.

While it was not my decision to use TI's analog input digital amplifiers in our current Sherwood R-904n NetBoxx receiver, I do take some comfort in the fact that NetBoxx uses the lossless solution.

Jeff
post #1792 of 1899
Quote:
Originally Posted by Stereojeff View Post

I too was beguiled by the seeming elegance of many of today's Class D solutions where the signal remained in the digital domain from source to output filter. This pollyanna notion was quashed several years ago when I attended and AES LA Chapter meeting hosted by noted audio educator John Vanderkooy. Vanderkooy pointed out that the analog to PWM conversion was lossless while the PCM to PWM conversion was not. Another myth shattered.

While it was not my decision to use TI's analog input digital amplifiers in our current Sherwood R-904n NetBoxx receiver, I do take some comfort in the fact that NetBoxx uses the lossless solution.

Jeff

Do you have a reference for this information? Thats a really odd blanket statement to make. There are multiple ways to generate the PWM signal from analog or PCM inputs. Generally all are theoretically perfect, however in practice there are imperfections in all. I'm not sure what you really mean by 'lossless' in this context either. You mean introduces distortion of some type? Or doesn't represent the full bit range? or something else?
post #1793 of 1899
xianthax:

I am a technically adept sales and marketing guy but I am no engineer. Beyond the lecture from Professor Vanderkooy, I have no additional details.

Jeff
post #1794 of 1899
Quote:
Originally Posted by xianthax View Post

You literally have no idea what you are talking about, actually zero technical knowledge.


This is a non-issue if the designer has done his job correctly.


A digitally controlled Class D amp is a D/A converter.


Not really true, you still require feedback paths and those paths now need to feed into a controller instead of an analog op amp based input filter.


Not true for the same level of performance (today). Not being able to introduce negative feedback to an analog input means you need to provide feedback digitally to the controller. You replace a couple op-amps with a DSP, which is not generally a cost win.


No idea what makes you think this is true.


Probably not. You replace some op amp input filters with a large DSP based controller which requires about the same number of external components, bypass caps, etc.


Not sure what the digital input to a class D amp has to do with this. Almost all methods of doing digital audio to PWM conversion is built in the ASIC, its not programmable.


Throwing bricks in glass houses and all that. Also what on earth do you mean about "high frequency supplies react much faster" i really don't think you understand how a switching mode power supply works in comparison to a linear regulator.


For the 5,000th time, its not even an all digital amp section! The pulsus IC in that design isn't even involved in the class D section!


Speaking of vested interest, how much Samsung stock do you own?

Before you run out the door to get this high performance AVR, one should read this review by Audioholics..

http://www.audioholics.com/reviews/r...amsung-hw-c700

Also this AVR has many HDMI interoperability issues especially if not used with Samsung components, as it was never certified for HDMI/HDCP compliance. In talking with 1 of the managers from Fry's Electronics, he mentioned that the return rate for this AVR was 27%..

In the end, one should stay kleer of this one...
If you still want one wait another month and they will be on E-bagger as B Stock for <$199..

Just my $0.02...
post #1795 of 1899
Quote:
Originally Posted by xianthax View Post

You literally have no idea what you are talking about, actually zero technical knowledge.

I see you've acquainted yourself with HiFiFun.

He does a mean job quoting marketing claims though!
post #1796 of 1899
Quote:
Originally Posted by M Code View Post
Before you run out the door to get this high performance AVR, one should read this review by Audioholics..

http://www.audioholics.com/reviews/r...amsung-hw-c700

Also this AVR has many HDMI interoperability issues especially if not used with Samsung components, as it was never certified for HDMI/HDCP compliance. In talking with 1 of the managers from Fry's Electronics, he mentioned that the return rate for this AVR was 27%..

In the end, one should stay kleer of this one...
If you still want one wait another month and they will be on E-bagger as B Stock for <$199..

Just my $0.02...
I don't know much about the a / b / d amp's and receivers but I got the idea that audioholics thought this avr was fine.

Here's a quote from their conclusion: "If you are in need of elite, high end sound and tons of video processing, then this isn’t the product for you, but for those looking for an elegant, all encompassing product to satisfy all of your AV/home theater needs, you'll be hard-pressed to match this kind of value and flexibility for your hard-earned money."

I think this avr was $250 on amazon and it was $200 on newegg apperently.
post #1797 of 1899
Quote:
Originally Posted by HiFiFun View Post

We read of the major weakness of almost all class D amplifier designs:
"Like class D amps in general, ICE-power converts an analog signal into a train of pulses with rapidly switching output devices..."
Why does ICE DIGITAL require an ANALOG signal?
In other words, since todays signal sources are digital, why is it necessary to convert these digital signal to analog just to drive a "digital" amplifier?
Why not just drive the digital amplifier with a digital signal???

Having owned about eight different class D amplifiers, I think there is something to be said for this approach.

However, I'm very sceptical about where HiFiFun is coming from - in the other thread I recall he said "we" instead of "I" on a few ocassions, and betrayed his vested interests.

An all-digital amp isnt the be-all and end-all though. The NAD M2 is expensive for a reason, and the Sony 9100 is better than the cheaper but architecturally-identical 7100 for presumably the same reason.

I think there are some great digital amps around, but they're not great because they're digital - its because they were developed well.

Nick
post #1798 of 1899
Here is a list of advanced nasty electrical issues you avoid by going with an ALL-digital receiver. Of course none of these issues are ever discussed at AVS:
Topics to be explored at CEDIA:
• Isolated ground branch circuits – when they are a bad idea
and when they are good
• causes and code-compliant cures (not cheater plugs) for hums
and buzzes (use $100 transformers)
• Video roll bars and measuring cable
shield resistances
• The limits of ground voltage differences when using
unbalanced video interfaces
Understanding of analog Common-Mode Rejection Ratio (CMRR) specs,
what happens in the “real world,” the relation of CMRR to signal
path design and the role hostile (read digital) electrical environments play in
signal path design

• Shield Current Induced Noise (SCIN) from different signal
wiring construction, both RF and AF
• Understanding linear vs. non-linear loads and how they impact
parasitic induction on grounding conductors
• Isolation transformers, phasing of supply conductors and
balanced power systems – including Ground Voltage Induction (GVI) in various wiring types
• Real-time analysis and measurement of radiated AC
electromagnetic fields of 7 different wiring methods and
the impacts of induction on each
• Causes of “bootleg grounds” and how to easily find them,
wiring reversals, stray fields, EMC
• Three-phase vs. single-phase and the impact on the signal path
• Surge and spike protection technologies
• Practical tips and tricks for saving time and doing it right when
loading equipment in racks and connecting audio/video signal
to electronic components
• the wisdom of converting digital signals into analog in a noisy RF environment, then (even better) creating pseudo digital pulses.

Thanks largely go to Jensen Transformers!
post #1799 of 1899
Quote:
Originally Posted by welwynnick View Post
Having owned about eight different class D amplifiers, I think there is something to be said for this approach.

However, I'm very sceptical about where HiFiFun is coming from - in the other thread I recall he said "we" instead of "I" on a few ocassions, and betrayed his vested interests.

An all-digital amp isnt the be-all and end-all though. The NAD M2 is expensive for a reason, and the Sony 9100 is better than the cheaper but architecturally-identical 7100 for presumably the same reason.

I think there are some great digital amps around, but they're not great because they're digital - its because they were developed well.

Nick
Thanks for the response Nick. Glad to see you read the posts so methodically!

Pulsus all digital amps have been "well developed" over the last 10+ years. Now they are highly integrated system-on-a-chip (SOC).
This all digital approach is really just common sense and a great way to reduce costs, weight and power, while improving the sound quality.

Further Samsung has the deep pockets to sell these at little or no profit (to gain market share). Samsung has demonstrated ruthless business practices. Once they corner the market they raise prices sky-high (as with last years first LED Tvs).

My bias is to identify new technologies which benefit the consumer, as I've spent decades identifying the many which lead nowhere, except to lighter pockets!

One of the greatest sonic attributes of the Pulsus technology is to reveal the coherent multi-channel atmosphere created in the recording or the studio. For example, it makes hearing Back to the Future Blu-ray an entirely new and satisfying experience.

What I've learned is digital and analog are like oil and water: they don't mix well over a 120db dynamic range!
post #1800 of 1899
Every time he posts i'm left with my face in my palm....
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