KeithL
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Posts: 10,273
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Post by KeithL on Oct 28, 2022 9:16:28 GMT -5
Just a bit of clarification here... Many modern components, including many DAC chips, most microcontrollers, and a wide variety of other complex chips, are somewhat proprietary... In the sense that there may not be a different chip that is a pin-compatible replacement. With a simple transistor, or a logic gate, you may actually be able to buy the same part number from several different vendors. But, with a custom microcontroller, it's quite possible that only one vendor has the patent, or the design, and they are the only source. (And, if they stop making it, or go out of business, "there just plain aren't going to be any more".) And, at the manufacturer level, chip fabs are horrifically expensive to set up and run... So only a few of the largest vendors have multiple fabs. And making complex chips like DACs is not nearly as simple as "setting the machines to stamp out another chip". They require multiple complex processing steps which can take a long time to set up and complete... So it's usually not practical to "outsource the manufacture of their chips to another plant". It's also not as simple as "turn on the foundry and run a few more"... It can take weeks or months for a foundry to "switch on" and "gear up" to making a particular chip or type of chip. And that can cost a LOT of money. And, when it comes to DAC chips, they fall somewhere in-between in terms of being proprietary. The basic functions and capabilities of most high-end DAC chips are rather similar... so finding one that will work in a particular application isn't too difficult. However, because the pinouts of the individual chips are somewhat proprietary, you can rarely find "a drop-in replacement" for a specific chip from a specific manufacturer. As far as I know, since their fire, AKM hasn't been sourcing AKM4490 chips; however they are currently shipping the AKM4493. And, even though the 4493 will do everything the 4490 does, the pinouts are not the same. This means that switching from one to the other requires a PCB redesign... (Remember that PCB design and layout is a complex subject all its own... so it's not nearly as simple as "drill the hole a few mm to the left and move a few traces".) So, at that point, it becomes "a design update", and you're effectively "deciding what chip to use this time". I would again remind everyone that there are quite a few vendors making excellent DAC chips that both perform very well and sound very good. We chose the AKM4490 because it performs very well and sounds good... but there are many other good DAC chips out there. And, to be quite blunt, as I've said before, the way a DAC performs depends on many factors other than the particular chip you happen to use. DAC chips are NOT like fine wine... where each has a totally unique sound signature... and no two are quite the same. (This is an audiophile myth that the DAC chip manufactures do their best to keep alive... and a certain few vendors in particular spend a lot to promote this idea.) I doubt EMO uses any proprietary semiconductors..... Companies also may use foundries for SEASONAL demand. You need more of a given device than you can make by the promised delivry date? Turn 'on' the foundry and problem solved.... What kind of EMO semiconductor problem are you trying to solve. It doesn't look like they are having a problem with delivery. Did you have a problem with your RMC delivery? |
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Post by PaulBe on Oct 28, 2022 10:38:44 GMT -5
Just a bit of clarification here... Many modern components, including many DAC chips, most microcontrollers, and a wide variety of other complex chips, are somewhat proprietary... In the sense that there may not be a different chip that is a pin-compatible replacement. With a simple transistor, or a logic gate, you may actually be able to buy the same part number from several different vendors. But, with a custom microcontroller, it's quite possible that only one vendor has the patent, or the design, and they are the only source. (And, if they stop making it, or go out of business, "there just plain aren't going to be any more".) And, at the manufacturer level, chip fabs are horrifically expensive to set up and run... So only a few of the largest vendors have multiple fabs. And making complex chips like DACs is not nearly as simple as "setting the machines to stamp out another chip". They require multiple complex processing steps which can take a long time to set up and complete... So it's usually not practical to "outsource the manufacture of their chips to another plant". It's also not as simple as "turn on the foundry and run a few more"... It can take weeks or months for a foundry to "switch on" and "gear up" to making a particular chip or type of chip. And that can cost a LOT of money. And, when it comes to DAC chips, they fall somewhere in-between in terms of being proprietary. The basic functions and capabilities of most high-end DAC chips are rather similar... so finding one that will work in a particular application isn't too difficult. However, because the pinouts of the individual chips are somewhat proprietary, you can rarely find "a drop-in replacement" for a specific chip from a specific manufacturer. As far as I know, since their fire, AKM hasn't been sourcing AKM4490 chips; however they are currently shipping the AKM4493. And, even though the 4493 will do everything the 4490 does, the pinouts are not the same. This means that switching from one to the other requires a PCB redesign... (Remember that PCB design and layout is a complex subject all its own... so it's not nearly as simple as "drill the hole a few mm to the left and move a few traces".) So, at that point, it becomes "a design update", and you're effectively "deciding what chip to use this time". I would again remind everyone that there are quite a few vendors making excellent DAC chips that both perform very well and sound very good. We chose the AKM4490 because it performs very well and sounds good... but there are many other good DAC chips out there. And, to be quite blunt, as I've said before, the way a DAC performs depends on many factors other than the particular chip you happen to use. DAC chips are NOT like fine wine... where each has a totally unique sound signature... and no two are quite the same. (This is an audiophile myth that the DAC chip manufactures do their best to keep alive... and a certain few vendors in particular spend a lot to promote this idea.) What kind of EMO semiconductor problem are you trying to solve. It doesn't look like they are having a problem with delivery. Did you have a problem with your RMC delivery? I've become disenchanted with almost all of the audio myths and the manufacturers/vendors/reviewers who promote them. I admit to believing some of them over the years. There is still a lot of room for honest differences of opinion. Perhaps a sub-assembly to socket approach, for some chips, would help reduce the need for full PCB redesign when you need to source components with different pinouts. Like this - en.wikipedia.org/wiki/Small_outline_integrated_circuit#/media/File:PIC16LF870_in_SOIC_Socket_(cropped).jpg |
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Post by audiosyndrome on Oct 28, 2022 10:48:32 GMT -5
The example shown is waaaaaaay to big in every dimension to be practical for use in an AVR or prepro. ☹️
Russ
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Post by PaulBe on Oct 28, 2022 10:56:41 GMT -5
The example shown is waaaaaaay to big in every dimension to be practical for use in an AVR or prepro. ☹️ Russ The example is just an example of 'a' socket. It's the first pic I found. I have a couple of sockets on my high part count computer MB. More parts than in the RMC prepro  Perhaps the Main PCB of a prepro should be built like a computer MB... oh wait... Planning for change and options is practical. How are those magic $700 power cables working for you? triodewirelabs.com/product/seven-plus-american-series/Just wait till they come out with the Seven Plus Plus power cables next year. Nirvana! |
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KeithL
Administrator
Posts: 10,273
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Post by KeithL on Oct 28, 2022 11:32:30 GMT -5
It's a nice idea but there are several things that make it impractical for modern circuitry. First of all it is pretty big... use one of those for every chip and you would increase the size of many designs unreasonably. Second of all, those sockets cost money, so that would add to the price of the product. (You may be surprised to know that some of those cool connectors actually cost more than a modern high-performance DAC chip.) Third is that any sort of mechanical connection adds the risk of bad connections, oxidized connections, and broken solder joints. (Just look at all the bits, pieces, and contacts between the chip and the PCB compared to soldering it directly onto the board.) But the fourth and biggest issue is lead length and run geometry. With many high speed digital chips the leads must be kept as short as possible. With some modern chips even having one board trace being a few millimeters longer than another can cause timing problems. And, with two traces running in parallel, you have capacitive coupling between them. And there is capacitance between those leads and the unit's case... and everything nearby... And, if a trace bends too sharply, that bend has inductance. And, when I look at that socket, to me each of those leads going from the board to the chip looks like a little vertical antenna. One of the advantages of SOIC chips is short legs... and some SMD chips have NO legs... so you have the shortest possible connection between the silicon in those chips. Those sorts of sockets would work for some op-amps running at audio frequencies. But not for a DAC. (I'm not saying that they couldn't be made to work... but merely that they would make things harder rather than easier.) The closest you could come would be to put the DAC, along with all of its associated circuitry, onto their own little board. (At which point your DAC would be modular... which is something some vendors do.) But that too adds cost and complexity... and another board... and more connectors and connections. (Remember that each different type of board must be designed and tested... and each will have its own manufacturing risks and issues as well.) And, if you look at one of our RMC-1's or XMC-2's, you'll find that all of the DAC chips ARE on one circuit board. So, collectively, they are all modular. I should also mention that the next generation goes even further. Check out COB (chip-on-board) construction - which is used on most modern phones and for some components on some computers - like the Raspberry Pi. The silicon chip is mounted directly to the PCB... no socket... no legs... and no package at all... |
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Post by fbczar on Oct 28, 2022 11:49:26 GMT -5
Restarting an XMC-2 periodically may not be a bad idea. Recently the usually dead middle phantom center channel effect in stereo has drifted to the right in my system. I tried everything with no luck. Then I did a hard restart and the phantom center was back in dead center. I do wonder what causes the drift, but when it happens a restart always fixes it. I had this occur with my xmc-1 also. After awhile the reboots wouldn't fix it and it was off to Franklin. Well, that is not good to hear. It is a strange effect. the center image moves about 2 or 3 feet to the right and it is less solid. No amount of adjusting levels makes any difference. After the restart everything is just right. |
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Post by PaulBe on Oct 28, 2022 11:58:40 GMT -5
It's a nice idea but there are several things that make it impractical for modern circuitry. First of all it is pretty big... use one of those for every chip and you would increase the size of many designs unreasonably. Second of all, those sockets cost money, so that would add to the price of the product. (You may be surprised to know that some of those cool connectors actually cost more than a modern high-performance DAC chip.) Third is that any sort of mechanical connection adds the risk of bad connections, oxidized connections, and broken solder joints. (Just look at all the bits, pieces, and contacts between the chip and the PCB compared to soldering it directly onto the board.) But the fourth and biggest issue is lead length and run geometry. With many high speed digital chips the leads must be kept as short as possible. With some modern chips even having one board trace being a few millimeters longer than another can cause timing problems. And, with two traces running in parallel, you have capacitive coupling between them. And there is capacitance between those leads and the unit's case... and everything nearby... And, if a trace bends too sharply, that bend has inductance. And, when I look at that socket, to me each of those leads going from the board to the chip looks like a little vertical antenna. One of the advantages of SOIC chips is short legs... and some SMD chips have NO legs... so you have the shortest possible connection between the silicon in those chips. Those sorts of sockets would work for some op-amps running at audio frequencies. But not for a DAC. (I'm not saying that they couldn't be made to work... but merely that they would make things harder rather than easier.) The closest you could come would be to put the DAC, along with all of its associated circuitry, onto their own little board. (At which point your DAC would be modular... which is something some vendors do.) But that too adds cost and complexity... and another board... and more connectors and connections. (Remember that each different type of board must be designed and tested... and each will have its own manufacturing risks and issues as well.) And, if you look at one of our RMC-1's or XMC-2's, you'll find that all of the DAC chips ARE on one circuit board. So, collectively, they are all modular. I should also mention that the next generation goes even further. Check out COB (chip-on-board) construction - which is used on most modern phones and for some components on some computers - like the Raspberry Pi. The silicon chip is mounted directly to the PCB... no socket... no legs... and no package at all... Thanks for adding all these points. I knew the discussion would go full circle. Every connection is a cost and potential failure point. Any excess connection length is a potential parasitic component. I get it. Been there and done that. Modular takes different forms. I like EMOs approach - cost effective, minimized failure points, elegant design. An example of how NOT to build is the Marantz 8005. The inside of a Marantz 8005 is a mess. "Second of all, those sockets cost money, so that would add to the price of the product. (You may be surprised to know that some of those cool connectors actually cost more than a modern high-performance DAC chip.)". Actually, I'm not surprised anymore. I used to be surprised. When I first saw I-Pads, I knew something like that would eventually replace the expensive Penny & Giles faders on an audio console. and that cheap monitors would replace the expensive Dorrough meters in the bridge. What did surprise me is how fast the changes occurred. Thanks for the peek into G4P construction. I am very curious about your planned audio section upgrade. Now, how about that FWv3.0? Sir? |
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Post by leonski on Oct 28, 2022 13:59:37 GMT -5
I'm sure that while you don't comprehend what I wrote, you also know best.
Have fun! That's the important part...
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Post by foggy1956 on Oct 28, 2022 14:35:38 GMT -5
I had this occur with my xmc-1 also. After awhile the reboots wouldn't fix it and it was off to Franklin. Well, that is not good to hear. It is a strange effect. the center image moves about 2 or 3 feet to the right and it is less solid. No amount of adjusting levels makes any difference. After the restart everything is just right. With mine I could center the image with balance control but the center would continue to drift over time until it got a hard reboot. And yes it would become less solid which was hard to discern until the reboot brought everything back into focus, but as I said eventually the reboots wouldn't fix the issue. |
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richb
Sensei
Oppo Beta Group - Audioholics Reviewer
Posts: 890
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Post by richb on Oct 28, 2022 16:27:45 GMT -5
Denon has moved to TI DAC chips for the new 3800H AVR, measured here: www.audiosciencereview.com/forum/index.php?threads/denon-avr-x3800h-review.38574/The results are not stunning, but to be fair, mostly because of implementation issues. One concern is the relatively poor reconstruction filter.  Clearly DAC implementation is matters, but it would be good to know if the G4 processor DACs are considered SOTA. Manufacturers of high-end products like to advertise the inclusion of high-end DACs because it sells product. - Rich |
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Post by leonski on Oct 29, 2022 1:23:41 GMT -5
'making it work' would appear to be nearly as much ART as SCIENCE.....
Factor in cost constraints? Product lifecycle? and a few Other considerations and you are officially NUTS.
Any way to simply SKIP the internal DAC and go with a premium aftermarket item which I'd hope would be of lasting value?
I'm not convinced that HT receivers are meant to go more than 4 or maybe 5 years.....TOPS....
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Post by PaulBe on Oct 29, 2022 7:50:22 GMT -5
Paint is the science. Art is the content - what we do with the paint. The only thing of lasting value is the art.
DACs are the dodo bird that is not quite ready for extinction. The only DAC needed is the interface between amplifier and speaker.
All the talk about different DACs, fabs, foundries, parasitic elements, PCB layout, yada-yada-yada, is academic. COB (chip-on-board) construction is interesting to me. I think most circuit boards will eventually look like there is nothing on them; everything embedded in the multi-layer board.
No product as sophisticated as a current prepro, in the quickly evolving field of HT, has a life cycle of more than 5 years. Few people in this industry want to commit to standards that last. The only thing in the industry that has a lasting life cycle is snake oil. Snake oil lubricates the ‘circle of confusion’.
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Post by audiosyndrome on Oct 29, 2022 7:53:34 GMT -5
The example shown is waaaaaaay to big in every dimension to be practical for use in an AVR or prepro. ☹️ Russ The example is just an example of 'a' socket. It's the first pic I found. I have a couple of sockets on my high part count computer MB. More parts than in the RMC prepro Perhaps the Main PCB of a prepro should be built like a computer MB... oh wait... Planning for change and options is practical. How are those magic $700 power cables working for you? triodewirelabs.com/product/seven-plus-american-series/Just wait till they come out with the Seven Plus Plus power cables next year. Nirvana! Not $700 when the manufacturer is a fellow club member. You need to lighten up guy. 😜 |
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Post by PaulBe on Oct 29, 2022 8:01:34 GMT -5
The example is just an example of 'a' socket. It's the first pic I found. I have a couple of sockets on my high part count computer MB. More parts than in the RMC prepro Perhaps the Main PCB of a prepro should be built like a computer MB... oh wait... Planning for change and options is practical. How are those magic $700 power cables working for you? triodewirelabs.com/product/seven-plus-american-series/Just wait till they come out with the Seven Plus Plus power cables next year. Nirvana! Not $700 when the manufacturer is a fellow club member. You need to lighten up guy. 😜 I get it. You are advertising.  What club? I guess I'm not a member of the 'club'. It's a big 'club', and I'm not in it. Did you 'cryogenically' treat your house wiring? I do 'burn-in' my house wiring everyday - 24/7 - every wire, from the x-former in the yard, through the aluminum main, to the copper in the walls, to the outlets in the house. The house be cookin'.  |
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Post by msimanyi on Oct 29, 2022 10:32:33 GMT -5
Please correct me if I'm wrong, but this *is* the thread for discussing the G4P line, isn't it?
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Post by PaulBe on Oct 29, 2022 10:44:50 GMT -5
Please correct me if I'm wrong, but this *is* the thread for discussing the G4P line, isn't it? KeithL says the G4P will have some COB (chip-on-board) construction. That is interesting to me. I would like more details on the audio circuitry upgrade too. Also, when will FWv3.0 be coming, and what new FW features will be in the G4P? I guess suggesting a modular way to choose different DACs with different pin-outs, when supply chain issues occur, was a non-starter. KeithL says the RMC is already modular enough to easily accommodate changes if needed. DACs are cheaper than connectors, and connectors have reliability problems. With the G4P COB construction, there will be less to talk about or critique. PCBs will be more of a smooth face. Probably just as well. Fewer 'my DAC is better than your DAC' discussions. 'TO DAC or not to DAC' is a more worthy discussion - Nouns vs verbs... |
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Post by AudioHTIT on Oct 29, 2022 10:47:34 GMT -5
Any way to simply SKIP the internal DAC and go with a premium aftermarket item which I'd hope would be of lasting value?… First you have to remember there are a minimum of 16 channels to ‘DAC’, possibly more if expansion boards are available. Personally I don’t want more boxes and cables when I find that the quality of the built in DACs and associated components works well for me. I’d also argue that it’s not the DAC that becomes obsolete, but rather other parts of the processor dealing with industry standards (Dolby, DTS, HDMI, etc.), and possibly processing and memory. As far as two channel purists who want to dabble with DACs, they have a nice pair of balanced XLR inputs to connect to (RCA available too), so they’re not left out either. I’ll probably be fine with the extra attention they typically give to the LCR channels — though I’m still using a DC-1 DAC/Preamp on my desktop, what is that, almost 10 years old now? 😱 (notice how I did the trendy thing of turning a noun into a verb, I’m reminded of it regularly when local ads tell us PG&E is “undergrounding” their power lines). |
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Post by leonski on Oct 29, 2022 18:03:26 GMT -5
Paul? A couple things....if I maybe so bold. First? reviewers ARE important. but you must know them to the point of what you value VS what they value.....So if you agree or disagree, you can 'clock' what the reviewer is on about and make a determination of somethings value to YOU. I see few just plain old 'bad' reviews. the reviewers job is to find the good and the value..... I'd TEND to agree with Audio. DACS do not necessariy become obsolete......but the supporting stuff, like many of the proprietary chips for 'industry standards' DO.... An exception might be ONE-BIT DACs which came and went in a big hurry. Channels into a dac might be just a matter of 'switching'.....I use 'just' advisedly....since it is I suspect a little more complicated. On the Simple side? I use a 4-in / 1-out optical switch. Works the wonder and is cheaper than dirt. And not even as large as a pack of playing cards. An OPTICAL equivelent of what WAS an old-school tape monitor circuit might work. HT or PRE does the swithcing.......out / in to the external DAC than back to the ONE set (more might be nice) of inputs at the HT or PRE........ At thei LINK? A whole PILE of Demo or Evaluation boards for DACs.......this link to Digikey so not exactly a fly-by-night operation. www.digikey.com/en/products/filter/evaluation-boards-digital-to-analog-converters-dacs/793 |
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Post by PaulBe on Oct 29, 2022 20:01:42 GMT -5
Paul? A couple things....if I maybe so bold. First? reviewers ARE important. but you must know them to the point of what you value VS what they value.....So if you agree or disagree, you can 'clock' what the reviewer is on about and make a determination of somethings value to YOU. I see few just plain old 'bad' reviews. the reviewers job is to find the good and the value..... I'd TEND to agree with Audio. DACS do not necessariy become obsolete......but the supporting stuff, like many of the proprietary chips for 'industry standards' DO.... An exception might be ONE-BIT DACs which came and went in a big hurry. Channels into a dac might be just a matter of 'switching'.....I use 'just' advisedly....since it is I suspect a little more complicated. On the Simple side? I use a 4-in / 1-out optical switch. Works the wonder and is cheaper than dirt. And not even as large as a pack of playing cards. An OPTICAL equivelent of what WAS an old-school tape monitor circuit might work. HT or PRE does the swithcing.......out / in to the external DAC than back to the ONE set (more might be nice) of inputs at the HT or PRE........ At thei LINK? A whole PILE of Demo or Evaluation boards for DACs.......this link to Digikey so not exactly a fly-by-night operation. www.digikey.com/en/products/filter/evaluation-boards-digital-to-analog-converters-dacs/793Hi Leon, thanks for your thoughtful post. I use reviewers’ comments as I see fit. Reading between the lines is valuable. The reviewer’s main job is maintaining his guru status and paycheck. To borrow the sentiment of a Shaw quote - ‘Those who can’t, review’. They are sort of like most broadcast talent – more image than substance. I’m making a generalized statement. It doesn’t apply to all. But, as a director I knew used to say – “Cue the meat”. I don’t have the level of interest you have in outboard DACs. I have an oppo 205, and it doesn’t have near the quality of sound of my RMC-1L. My oppo 205 doesn’t have near the quirky problems of my RMC-1L. I won’t go back to using the 7.1 outputs of the oppo 205. Before I bought the RMC-1L, I was using the oppo 205 as a player and prepro, with an additional input source. It worked well, but the sound of the RMC-1L was an ear opener I didn’t expect. I had a number of reasons for thinking the RMC-1L would not sound as good or better than the oppo 205. My reasoning was flawed. Digikey is a great place for parts. Bought my first parts from them 40 years ago. Back when their catalog was a newspaper-like flyer, and there was no internet or website. IIRC, I first contacted them from an ad in Audio Amateur. I bought many parts from them over the years, for both hobby and business. It was amazing how their business grew, along with the size of their catalogs. I am looking forward to development of G4P. I expect it’s reasonable lifecycle will be about 5 years. About the same as a G3P. It’s not like a Marantz9 or ARC D76 tube amp. I did have an ARC D76. Wish I hadn’t sold it. Wonder what a matched pair of KT88’s go for today. |
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Post by leonski on Oct 29, 2022 20:38:04 GMT -5
I'm cynical about reviewers, too. But I have made peace and KNOW how to use them to my advantage. I know of one reviewer with whom I nearly always disagree. Useful.....If he hates it? I may like it....and flip-side, too.
You can discard them or discredit them.....But MANY less fortunate than you or I take a lot of what they say TO HEART......
YOUR job is to see thru the BS to see what GOOD they can actually do for you......
My favorite expression? 'Sell The Sizzle'.......
At one point, the OPPO BR players were aspirational for me. but I could never rationalize the large cost.
I DO have the DV980 or DV980H......I'd have to actually go LOOK. And that was fine, since the upsampling was among the best available and the other performance was tops, as well.
Impossible to find anything like this today in the 'new' market....
I have NO real interest in outboard DACS. I have a Cambridge Audio DACMAGIC+ which needs repair. And since it is out of production? You'd THINK that Cambridge would shoot me at least a Schematic.
NO SUCH LUCK. This is my 2nd and LAST go around with Cambridge. Parasites, IMO. I spent BIG BUCKS on a cd player.....at that point the 840 level. And they wanted to charge me to UPGRADE the firmware
so it would actually be useful with my Apple Airport Express, with which it had timing issues......I originally bought the DacMagic+ with the Intent of getting the Bluetooth Dongle so I could stream via bluetooth.....which
while not the best, certianly is adequate to do housework or cooking to........given APTx and some of the other 'advanced' alphabet soup......But they got 100$ for it! During the same timeframe, EMO got maybe 25$ for the
SAME Darn Thing......A USB Dongle / BT / APTx.....
No Mas CA for ME.....ever.
You don't WANT to know how much a matched pair of KT88s go for today. And since you are not likely to need just 2 of 'em? I'm looking at the VTA M125 monoblock power amp. In KIT Form.
They have 4x 6550 output tubes PER and you can install up to KT120......Just keep an eye on the BIAS. With the higher current draw of the KT120 tube set? I'd throw-in for a Weber SS rectifier.....
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I doubt EMO uses any proprietary semiconductors.....
What club? I guess I'm not a member of the 'club'. It's a big 'club', and I'm not in it.
