thanks Vunce for testing this and detailed progress, so we know another good thing
No problem Miro!
You created a board that’s very friendly to “Tweak” with, thanks for that
I have spare boards made, but shipping international might be costly. If there is interest I could post files for the I/V boards.
I also have a JLSounds I2SoverUSB board on the way, would there be an advantage to connecting the way Nautibouy inquired about?
I did it with the intention for both, less DIY people + suitable for more DIY people
You are right, international shipping is expensive, it is best to only send locally. Instead of international shipping, it can be cheaper to order it directly from the pcb manufacturer.
The logic on the PCB is very fast. As the audio sampling is controlled with LRCK directly from jlsounds (or any USB/I2S), I don't see an advantage here, but I may be wrong
You are right, international shipping is expensive, it is best to only send locally. Instead of international shipping, it can be cheaper to order it directly from the pcb manufacturer.
The logic on the PCB is very fast. As the audio sampling is controlled with LRCK directly from jlsounds (or any USB/I2S), I don't see an advantage here, but I may be wrong
mostly in practical side (some shift in bits), not in the audio quality,
i2s data must be converted anyway for these older DACs (the most common format is PCM, used in AD1862, so I2S is converted to PCM), either internally in an fpga, processor (jlsounds does it) or using a glue logic (this case) ... new DACs do this conversion automatically and support many input protocols
i2s data must be converted anyway for these older DACs (the most common format is PCM, used in AD1862, so I2S is converted to PCM), either internally in an fpga, processor (jlsounds does it) or using a glue logic (this case) ... new DACs do this conversion automatically and support many input protocols
I am unable to recommend a reliable ebay source, because all ebay sources I knew are sold out, "thanks" to this thread
you can find something on ebay now (I found for about $8), but the condition is the risk to consider - if can you risk this money, go and try it,
... genuine replacement from rochester can wait for you some time, and will be worth if you will like the result
you can find something on ebay now (I found for about $8), but the condition is the risk to consider - if can you risk this money, go and try it,
... genuine replacement from rochester can wait for you some time, and will be worth if you will like the result
I did tried to buy from Ebay, a supplier in china.
Paypal went thru successfully however, they cancelled my order next day and refund me in full!
I will start a mini GB to purchase directly from Rochester Electronics, the price will be at costs plus shipping in the Group Buy section.
Paypal went thru successfully however, they cancelled my order next day and refund me in full!
I will start a mini GB to purchase directly from Rochester Electronics, the price will be at costs plus shipping in the Group Buy section.
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As I'm going to use the JLSounds USB board as the 'source' for my AD1862 DAC project I'm considering doing my own PCBs to stack on top of the JLSounds.
My thinking is to lose the shift register front-end and the output section (for which there are many options) and just have small boards, with a single AD1862N per board, that can be stacked. It would keep everything compact and flexible with very short traces to the DAC chips.
Any thoughts/comments/observations?
My thinking is to lose the shift register front-end and the output section (for which there are many options) and just have small boards, with a single AD1862N per board, that can be stacked. It would keep everything compact and flexible with very short traces to the DAC chips.
Any thoughts/comments/observations?
Hi Meanie,
I purchased chips from the $8 eBay seller and paid for expedited DHL shipping. After almost 2 weeks without shipping confirmation, I contacted eBay. The next day the seller refunded my money.
Since the eBay prices have really gone up, Rochester is probably the best move now, you know they are genuine and shipping won't take 30 days!!
Good luck with your project!
I purchased chips from the $8 eBay seller and paid for expedited DHL shipping. After almost 2 weeks without shipping confirmation, I contacted eBay. The next day the seller refunded my money.
Since the eBay prices have really gone up, Rochester is probably the best move now, you know they are genuine and shipping won't take 30 days!!
Good luck with your project!
My concern would be the distance from the AD1862 Iout to the offboard I/V buffer stage.
I think that's controllable with some thought up front - might even be able to locate an I/V section (maybe based on your own experimental board) alongside the DAC chips.
Or maybe the I/V stage is stackable too? Thinking much is to be done.
I'm in no hurry as I don't even have the DAC chips yet (just signed up to Ivan's GB) and have several other projects to finish first.
Or maybe the I/V stage is stackable too? Thinking much is to be done.
I'm in no hurry as I don't even have the DAC chips yet (just signed up to Ivan's GB) and have several other projects to finish first.
Btw I use I2StoPCM from IanCanada there which is slaved by the Master Clock - I dunno what is slaved ... Bck ? or both Latch and Bck ?-
But here ith your board I plan to use the FifoPi with CCHD-957 as I have it already...and it's easy to further decoupling the cchd-957 and PS to make it sound...less sterile - i.e. fullier like a NDK- Sorry for the sound description, I don't care what are involved : jitter, distorsion, etc or at least my rational brain, yes, for the knowledge & curiosity but not the part of it that is enjoying music
!@Vunce : I believe those wild bandwidth/fast oaps suffers from our diy with extra boards... anyway I really advise to experiment with your opa861 : first try to swap the ceramics if they are in the nF range by those acrylic smds if the size casing is compatible with your layout. And try also if not already made (the two C0G of your pcb ?) a furter 1 nF or pico range ? - sorry I'm not a scope guy so if Miro has thoughts here ?-
Even soic to dip adaptators are a problem - Miro: any soic outputt planned with a separate buf stage as well ? We can make a GB from JBLCP to reduce costs and dispatch by continents for the ones needing one board and not 5 ... while I'm not the gentle guy that served Nautyboy- Chi for China, Vunce for America, you or me for CE ?
I'm a little slow for the BOM because I'm waiting Andrea Mori for another project to make a standalone order at Mouser/Farnell but I spend that extra time to try to short my oaps whisch list to try... and list is evolving all the time !
opa1656 : dual channel... a winner, but soic adapter and single mng with wire may waste perhaps this cool chips ?
ada4627-1 : so exist in single but this opa1656 competitor is thinner and brghter, less fuller - chose your words- and much more expensive..
opa 810 : single, definitly advised for such task, though certainly not better in real life than aboves...
opa 210 : certainly cooler than opa211, ad811/812 that are too much fast to work with with adaptators...as the LM6071 of the list.
opa 1611-single- . opa 1652/46 : certainly better than the 1656 cause the extra soic adaptators. opa 2156 ?
I really want to try said "slow" dip8's, i.e. classic : single version of 2604 and NJM 4080DD...
In the JohnC 1656 thread, they say TI/BB is also going to pull the trigger on few more new oaps for audio and a guy made experiment to force the buff section of those oaps in class A... and they react very not the same to that tasks ...
Als an interressant about the sum of the impedance outputt of dac chip and the feedback ressitor of the I/V stage in order to choose between bipolars and Fets inputs... btw as I already stated in this thread, todays chips are so good that it is hard to make a clear choice when the ears are the final judge and Cmos is making many people agreeing today... My understanding at least ! John also inputed about I/V job by answering to members.
Edit, maybe I should try tube output stage before to pass away cause this stupid pandemy and the stupid deny of some...dunno, monney becomes a problem....
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Member
Joined 2006
AD1862 PCB layout
See post #108
I was thinking of using that i2s to pcm board too, but looks like painkiller has a better way to do it? Or simply sticking to using the glue logic chips as is maybe a good solution?
See post #108
I was thinking of using that i2s to pcm board too, but looks like painkiller has a better way to do it? Or simply sticking to using the glue logic chips as is maybe a good solution?
With Painkiller board, you MUST use weither I2StoPCM or JLSounds. Not sure he planed something else hat one of this two... I don't remember as he has a complex multichannel setup...but iirc he waw using the JLCSounds board.
Between both boards there are different trade off : JLCSounds : short distance from the ndks to the dac chip. I don't remember if JLCSounds has an isolator chip at the output ?!
Ian's gears : complex setup, sphagethis uf-l conexions everywhere despite the I2StoPCM is slaved. Advantage is about powersupplies : you can set up the sound by changing the main power supplu cap of each device before the dac board !
It's off topic : did you also purchased the Rogics AYA2 that comes after the 2014 version, DS & furthest? I missed the AYA4 USB...
... but the 2014's stays my ref !
Edit : bloody Hell, my poor memory : from post 104 of his thread : picture clearly shows 2 x I2S to PCM with a complex usb front end (cause multichannels & video/TV digital sources/streaming)
Between both boards there are different trade off : JLCSounds : short distance from the ndks to the dac chip. I don't remember if JLCSounds has an isolator chip at the output ?!
Ian's gears : complex setup, sphagethis uf-l conexions everywhere despite the I2StoPCM is slaved. Advantage is about powersupplies : you can set up the sound by changing the main power supplu cap of each device before the dac board !
It's off topic : did you also purchased the Rogics AYA2 that comes after the 2014 version, DS & furthest? I missed the AYA4 USB...
... but the 2014's stays my ref !Edit : bloody Hell, my poor memory : from post 104 of his thread : picture clearly shows 2 x I2S to PCM with a complex usb front end (cause multichannels & video/TV digital sources/streaming)
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Member
Joined 2006
Everything is reclocked here.
For NOS R-2R glue logic, BCK super accuracy is not so important (as in delta-sigma), just so they don't skip bits (match the data), in most real cases it is quite accurate. The resulting music signal is controlled from the slower LRCK (which is out of glue logic and is generated directly from USB/I2S source device).
There are other glue logic solutions (stop clock in AN-207 article from analog devices), but here is the LRCK controlled via glue logic, and the master-clock should already be used here for better accuracy of LRCK (BCK may not be enough), that's why I haven't done it yet and I probably won't even try. It pays off for DACs that can and will benefit from a stop-clock (definitely TDA1540, maybe TDA1541A).
PCM63, AD1862, PCM1704, PCM1702, are more resistant to digital interference.