Yamaha A-S801 Boost or Roll-Off?

[PENG]

Haha, @eargiant, my initial guess was that it was the PCM9211 but I eliminated that scenerio right off the bat because the chip shown in the photo you posted did not contain any of the numbers and more importantly, the fact that PCM9211 is not a DSP chip. Then in my post#52 based on block diagrams I had seen elsewhere, I suggested that (since it is a DSP) it is likely associated with the USB DAC. Yes the DAC chip has a build in DSP but that little one is most likely for signal filtering to reduce jitter etc, not really for any heavy duty signal processing. The DAC chip's job is mainly for digital to analog conversion, not DSP.

It turns out I guessed right, this DSP works with the USB-DAC. The reason it took me so long to find it is that it was discontinued since 2012.

http://media.digikey.com/PDF/PCNs/Texas Instruments/PCN20121114000_Obs.pdf

edit: I forgot to provide the part# of the chip and the link to the schematic.

https://www.manualslib.com/manual/1074970/Yamaha-A-S801.html?page=58#manual

It is the D81YK113DZKB400, identified as IC321 on the PCB, page 38 and the schematic is shown on page 58 in the USB_DAC section.

 

[M Code]

Man, I would be pissed if I found out that I bought a "separates" Integrated Amp that has a DSP chip used in Soundbars and TVs!

Like most of us have said over and over again, might as well buy an AVR.

Yamaha buys a lot of PCM9211s, very widely used in their pro audio and midi products, due their significant buying power/quantities pricing is very competitive....

Just my $0.02...

 

[<eargiant]

Man, I would be pissed if I found out that I bought a "separates" Integrated Amp that has a DSP chip used in Soundbars and TVs!

Like most of us have said over and over again, might as well buy an AVR.

Why would I trade features I want for those I don't need??

Haha, @eargiant, my initial guess was that it was the PCM9211 but I eliminated that scenerio right off the bat because the chip shown in the photo you posted did not contain any of the numbers and more importantly the fact that PCM9211 is not a DSP chip. Then in my post#52 based on block diagrams I had seen elsewhere, I suggested that (since it is a DSP) it is likely associated with the USB DAC. Yes the DAC chip has a build in DSP but that little one is most likely for signal filtering to reduce jitter etc, not really for any heavy duty signal processing. The DAC chip's job is mainly for digital to analog conversion, not DSP.

It turns out I guessed right, this DSP works with the USB-DAC. The reason it took me so ling to find it is that it was discontinued since 2012.

http://media.digikey.com/PDF/PCNs/Texas Instruments/PCN20121114000_Obs.pdf

Can you elaborate on what you mean by "this DSP works with the USB-DAC"? In reading the document M Code provided it seems like the chip can be used for various functions.

What exactly does the TI chip do in the Yamaha A-S801?

 

[PENG]

Why would I trade features I want for those I don't need??




Can you elaborate on what you mean by "this DSP works with the USB-DAC"? In reading the document M Code provided it seems like the chip can be used for various functions.

What exactly does the TI chip do in the Yamaha A-S801?

MCode was referring to a different chip, the PCM9211, that is not a DSP, not the TI made DSP chip that you posted the pictures for. I am quite sure the one I just found today is the one in your picture. Please re-read my post#61.

 

[<eargiant]

MCode was referring to a different chip, the PCM9211, that is not a DSP, not the TI made DSP chip that you posted the pictures for. I am quite sure the one I just found today is the one in your picture. Please re-read my post#61.

Ahh right. So I'll re-state the question I asked in post #39 when I posted a picture of the chip, "Do all DACs require a chip like this?" Also, what exactly does it do?

 

[gene]

I'm not following this thread closely but I ran some tests on my AS-801 just now using the DAC input and feeding it FLAC and SACD ISO files from JRiver. When I toggle between Pure Direct on/off, I don't hear any appreciable differences. This leads me to believe 1 of 2 things:
1. the OP has a defective unit
2. the OP has bionic hearing

If #1, it's possible the tone controls are defective and are NOT flat even in the 0 position or something else is at play. If #2, then I'd like to hire you as a reviewer since my ears are poop now. Hoping it's #1 though :/

 

[<eargiant]

I'm not following this thread closely but I ran some tests on my AS-801 just now using the DAC input and feeding it FLAC and SACD ISO files from JRiver. When I toggle between Pure Direct on/off, I don't hear any appreciable differences. This leads me to believe 1 of 2 things:
1. the OP has a defective unit
2. the OP has bionic hearing

If #1, it's possible the tone controls are defective and are NOT flat even in the 0 position or something else is at play. If #2, then I'd like to hire you as a reviewer since my ears are poop now. Hoping it's #1 though :/

I'll go with #2 -Bionic, it made me laugh!

I might take you up on the offer. Let's talk. You do the measurements and I'll do some of the subjective stuff.

 

[lovinthehd]

Maybe you two could exchange amps somehow and compare....

 

[PENG]

Ahh right. So I'll re-state the question I asked in post #39 when I posted a picture of the chip, "Do all DACs require a chip like this?" Also, what exactly does it do?

I don't know much about DACs and DSPs, but I believe a DAC as a complete device, not just the DAC chip itself, would have some sort of DSP on board. DSP, as the name implies, is there to handle signal processing that could include filtering, decoding, EQ etc. There are all kinds of DAC, the one the A-S801 uses in the USB-DAC section is just one of many, and is discontinued. If I have some spare time I would take a good look of the schematic page 57 and 58 iirc, and try to learn more about what it is for.

 

[PENG]

That’s the weird thing (at least to me) the DAC chip is an ESS 9010. That’s why I’m wondering what the TI DSP chip is for.

I did spend a few minute on the schematics today and found something interesting about the DAC chip(s) in this unit. It looks like the mid range ESS Sabre DAC chip is used for the USB DAC only while the optical and coax inputs are routed to a second dedicated DAC chip, a what I would consider a lower middle range chip, the PCM5101APWR that costs less than $3 a piece.

https://store.ti.com/PCM5101APWR.aspx

http://secure.ismosys.com/ordering/index.php

It is surprising that Yamaha would actually put higher end DAC chips in their AVRs, at least in their top 2 or 3 models anyway, than those in their $1000 two channel integrated amp.

 

[M Code]

I did spend a few minute on the schematics today and found something interesting about the DAC chip(s) in this unit. It looks like the mid range ESS Sabre DAC chip is used for the USB DAC only while the optical and coax inputs are routed to a second dedicated DAC chip, a what I would consider a lower middle range chip, the PCM5101APWR that costs less than $3 a piece.

https://store.ti.com/PCM5101APWR.aspx

http://secure.ismosys.com/ordering/index.php

It is surprising that Yamaha would actually put higher end DAC chips in their AVRs, at least in their top 2 or 3 models anyway, than those in their $1000 two channel integrated amp.

EZ to understand...
AVRs are mainly targeted for North America where here the typical buyer is easily influenced by hyping the latest/greatest chips. While integrated amplifiers are targeted mainly for Europe and other global markets outside North America... The integrated amplifier component buyer is less swayed by emphasizing just a single performance chip.

Just my $0.02..

 

[PENG]

EZ to understand...
AVRs are mainly targeted for North America where here the typical buyer is easily influenced by hyping the latest/greatest chips. While integrated amplifiers are targeted mainly for Europe and other global markets outside North America... The integrated amplifier component buyer is less swayed by emphasizing just a single performance chip.

Just my $0.02..

For a few dollars more why not go for the same 9016 or even the 9018 just to shut people up. The integrated buyers most likely won't mind paying for the extra specs anyway. I would also argue that avr shoppers actually may care less about which DAC chip is in their AVRs. Some don't even know what DACs are. I would also bet the integrated guys are more informed technically.

 

[M Code]

For a few dollars more why not go for the same 9016 or even the 9018 just to shut people up. The integrated buyers most likely won't mind paying for the extra specs anyway. I would also argue that avr shoppers actually may care less about which DAC chip is in their AVRs. Some don't even know what DACs are. I would also bet the integrated guys are more informed technically.

I can tell U a key question to differentiate products for the brands are to use different DACs to target specific markets and products. Note that the DAC parts pinwise are the same but there may be (3) different ranked DACs based on specs like good, better, best. My understanding during the DAC IC production stage all (3) levels come out of the same run but then are ranked based on measured electrical yield specs. I know 1st hand, Burr Brown(TI), Cirrus Logic DACs are done this way.

I have done multiple press presentations for major brand clients, and when we highlighted this new model (AVR, DVD) used a later, higher spec DAC it was always well noted. Did the DAC make an audible sonic difference, most likely not but it did make impressions.

Just my $0.02...

 

[PENG]

I can tell U a key question to differentiate products for the brands are to use different DACs to target specific markets and products. Note that the DAC parts pinwise are the same but there may be (3) different ranked DACs based on specs like good, better, best. My understanding during the DAC IC production stage all (3) levels come out of the same run but then are ranked based on measured electrical yield specs. I know 1st hand, Burr Brown(TI), Cirrus Logic DACs are done this way.

I believe you, and feel that we benefit from your vast experience in this field and your willingness to share some insider's knowledge now and then.

All I am trying to say it that people who don't mind paying more for "less" by going with integrated amps instead of a receive will likely appreciate it if integrated amps are fitted with higher grade parts. Looking at the schematics of the A-S801, I am finding more parts that are common to their distant cousins (AVRs), even the lower model AVRs. I am not complaining about their selection of DAC either, but only because ESS does not offer too many choices of 2 channel DACs. If they had opted for the ES9016S (2 channel), it would have been in par with the RX-A3060's ES9016 Ultra (8 channel).


RX-A3060, ES9016S - DNR: 124 THD+N: -110 (main 7 channels)
A-S801, ES9010K2M - DNR: 116, THD+N: -106 (USB DAC input)

The A-S801 also uses a PCM5101APWR, DNR: 106, THD+N: -92 for the optical and coax inputs. The same PCM5101 is found in some older and lower model AVRs.

I am not suggesting that using the 9016 equates to better sound quality, but it looks obvious to me the advantage of using the ones with lower specs is just cost saving. Just somewhat disappointing, that's all.

 

[M Code]

A few years back, early generation 5.1 AVRs used multiple chips; 3 x stereo DACs, stereo AD, DIR (Spdif Tx/Rx). But as silicon integration accelerated all (3) for the above functions were combined into a single IC costing <$1.75, compared to the mentioned 5 discrete chips of about $11. So almost overnight the bill of materials dropped >$9. All the ICs guys produced this all in 1 IC including AKM, AD, Cirrus Logic, ESS, and they were forced to price match.

Another area of cost reduction was for the audio DSPs, TI, AD, Fujitsu, Cirrus Logic each supplier had DSPs with increasing MIPs and memory. When buying silicon, costs decrease rapidly with increasing qtys, so when we would layout/design a DSP board module for an AVR we would design with the highest powered DSP even this was used in the entry-level model. Since our total buying QTYs was >350K units per year we were able to procure the highest powered DSP in qty @ a lower cost than buying the lowered powered DSP @ moderate qtys. This meant that the entry level AVR selling for $399 used the same DSP as the step-up AVR selling for $1499. Then common SW for the DSPs for all levels of AVRs would be used minimizing the validation/debugging time.

Things did get tougher as HD audio entered the market along with its higher royalties costs. Not only did the above MO apply for audio but also worked for the video processor/scaler ICs as well.

Just my $0.02...

 

[<eargiant]

Thank you PENG for your research and thank you M Code for providing the business perspective.

Two questions just for clarity:

If I'm using the USB input only (not Coaxial or Optical) that TI DSP chip is not in my signal path. Is this correct?

Are the tone controls and variable loudness adjustments stepped by the TI DSP chip or are they strictly analog?

 

[PENG]

Thank you PENG for your research and thank you M Code for providing the business perspective.

Two questions just for clarity:

If I'm using the USB input only (not Coaxial or Optical) that TI DSP chip is not in my signal path. Is this correct?

No! Did you read my previous posts #61 and #64? If you are referring to the TI DSP chip that is shown in the picture you posted, that chip is definitely in the signal path of the USB DAC. That chip is not in the path if you use the optical and coax inputs.

Are the tone controls and variable loudness adjustments stepped by the TI DSP chip or are they strictly analog?

I don't think so, again, the schematic doesn't show the TI DSP chip has anything to do with tone and loudness control. Unless I missed something, that chip is used solely with the USB DAC, probably has to do with the signal processing required for the DSD playback features.

For volume, tone and loudness control, so far I can see at least two processors involved, linked below so you can look them up.

The Renesas R5F3640ECNFA 16 bit microprocessor
https://www.renesas.com/en-us/doc/products/mpumcu/doc/m16c/r01ds0016ej0110_m16c64c.pdf

and the Rohm BD3473KS2 sound processor
http://www.tg-tech.com/chs/rohm/data/databook/audio/pdf/bd3473ks2-e.pdf
http://rohmfs.rohm.com/en/products/databook/datasheet/ic/audio_video/audio_processor/bd34704ks2-e.pdf

 

[<eargiant]

No! Did you read my previous posts #61 and #64? If you are referring to the TI DSP chip that is shown in the picture you posted, that chip is definitely in the signal path of the USB DAC. That chip is not in the path if you use the optical and coax inputs.

It just confused me when you later said this in post #70.

"It looks like the mid range ESS Sabre DAC chip is used for the USB DAC only while the optical and coax inputs are routed to a second dedicated DAC chip..."

It sounded like you reversed the original statement (or signal flow). So, I assume the "second dedicated DAC chip" you are talking about is the one M Code mentioned.

I don't think so, again, the schematic doesn't show the TI DSP chip has anything to do with tone and loudness control. Unless I missed something, that chip is used solely with the USB DAC, probably has to do with the signal processing required for the DSD playback features.

For volume, tone and loudness control, so far I can see at least two processors involved, linked below so you can look them up.

The Renesas R5F3640ECNFA 16 bit microprocessor
https://www.renesas.com/en-us/doc/products/mpumcu/doc/m16c/r01ds0016ej0110_m16c64c.pdf

and the Rohm BD3473KS2 sound processor
http://www.tg-tech.com/chs/rohm/data/databook/audio/pdf/bd3473ks2-e.pdf
http://rohmfs.rohm.com/en/products/databook/datasheet/ic/audio_video/audio_processor/bd34704ks2-e.pdf

OK thanks. So it's not a pure old school analog.

 

[PENG]

It just confused me when you later said this in post #70.

"It looks like the mid range ESS Sabre DAC chip is used for the USB DAC only while the optical and coax inputs are routed to a second dedicated DAC chip..."

It sounded like you reversed the original statement (or signal flow).

Not really, there's been no reversal of thing I said unless otherwise noted by myself. I think it may help if I summarize what has been discussed so far.

About the TI chip (that has been referred to as "TI DSP" chip you are interested in:

1. The TI chip M Code mentioned is the PCM9211, that as he said is an interface and multiplexer. In post#61 I even said "the fact that PCM9211 is not a DSP chip..." and "It turns out I guessed right, this DSP works with the USB-DAC. The reason it took me so long to find it is that it was discontinued since 2012."

From your post#63, I sensed you might have been confused so I repeated in post#64, "M Code was referring to a different chip, the PCM9211, that is not a DSP, not the TI made DSP chip that you posted the pictures for. I am quite sure the one I just found today is the one in your picture. Please re-read my post#61."

2. The D81YK113DZKB400 that I ID'ed from the schematics, and mentioned in post#61, is the TI DSP chip shown in the picture you posted. I also cited the page number in case you wanted to see the schematic. I have no way of confirming anything else other than it is in fact the one you have been questioning, as shown in the picture you posted, and in the service manual page 58. It may not even be a DSP chip, and the logo may just be a logo, unfortunately there is no Googleable info about this chip. On the drawing though, it does look like it takes the input signal from the USB port, "process" it and output it in DSD data that feeds the DAC chip ES9010K2M.

About the DAC chip(s):

So, I assume the "second dedicated DAC chip" you are talking about is the one M Code mentioned.

Again, no, the one M Code mentioned is not a DSP chip nor a DAC chip, the second DAC chip I mentioned for the optical and coax inputs is the PCM5101APWR, and I posted the link to the datasheet in post#70.

OK thanks. So it's not a pure old school analog.

I looks to me the serious stuff are handled by processors and the old school analog (there are resistors, capacitors, pots) stuff for the adjustment knobs. In the manual it does describe the loudness functions. I won't use it because it is nothing effective like the Audyssey's DEQ or presumably the latest Yamaha AVR's. version; and there is a slight risk if you use CD Direct or Pure Direct. This thing simply cuts the mid range instead of boosting the bass and treble according to a contour that matches humans hearing characteristics. I can see some potential advantages of that concept, but it does not out weigh the risk of damaging something if you are not careful. At least they cautioned you in the manual (page 16), for those who read instruction manuals.

By the way, no offense, but I think you maybe mixing up DSP and DAC a little. So just in case only, let's quote some Wiki definitions.

https://en.wikipedia.org/wiki/Digital_signal_processor

"A digital signal processor (DSP) is a specialized microprocessor (or a SIP block), with its architecture optimized for the operational needs of digital signal processing."

"In electronics, a digital-to-analog converter (DAC, D/A, D2A, or D-to-A) is a system that converts a digital signal into an analog signal. An analog-to-digital converter (ADC) performs the reverse function."

That sounds a little too broad, I prefer the one linked below:

http://www.analog.com/en/design-center/landing-pages/001/beginners-guide-to-dsp.html

Lastly, I can understand why you could be confused because the information are spread out in at least 3 or 4 posts. The trouble is, my digital systems knowledge are of the text book type, not the practical world type. So it takes me more time, and I can only spare a little time each day, to try and understand the schematics that are presented in such ways that unless you are an experienced applications engineer, it's very time consuming and difficult to try and understand everything in the service manual. I don't blame them because the schematics are part of a service manual not a text book for the academics and some amateurs.

 

[TLS Guy]

I have been following this post now and again.

I'm not sure much light has been shed.

What I can tell you from my Marantz 7701?

To me stereo, Direct and Pure Direct sound the same. However in Pure Direct there is less noise. If you put your ear to the speaker stereo and Direct sound the same, but there is a reduction in nose going to Pure Direct. I can say I have heard the noise in quite passages. My 8003 did not seem to have more noise in stereo and Pure Direct. So the newer pre pro does seem to get more noise from the video circuits. However the picture seems to me a little better on 7701, so I think the video circuits were upgraded. Now that is with digital source.

On the turntables which have their own preamps (Quad control units) I have a preference for Pure Direct but using my bass management and not the Pre/pro"s. I can switch between the two at the flick of a switch. There is no change in level. I think though this is because electronics is much more similar to the LP era with my bass management. On digital sources I can tell no difference at all whether I use my bass management or not.