Use this link for more details:
https://electrodac.blogspot.com/p/dac-ad1862-almost-tht-i2s-input-nos-r.html
Note: 8th pin on the I2S input header is missing connection with the GND (on some of my PCBs this pin is unconnected, if you are going to use it, solder it with the nearest GND pin on the header)
People who are selling brand new unused AD1862 or AD1865 chips:
Special tested DACs:
DAC702BH/CH (Glue logic - I2S data input) (result: audible digital noise on the output, not good for audio use)
DAC8811 (CPLD data input) (result: audible digital noise on the output, sound far away from very good audio, don't waste time and money on such DACs)
...
https://electrodac.blogspot.com/p/dac-ad1862-almost-tht-i2s-input-nos-r.html
Note: 8th pin on the I2S input header is missing connection with the GND (on some of my PCBs this pin is unconnected, if you are going to use it, solder it with the nearest GND pin on the header)
People who are selling brand new unused AD1862 or AD1865 chips:
- Paddy Garcia new group buy
- https://www.diyaudio.com/community/threads/ad1862n-j-dac-chips-for-sale.405922/
- https://www.diyaudio.com/community/threads/ad1862n-d.417897/
Special tested DACs:
DAC702BH/CH (Glue logic - I2S data input) (result: audible digital noise on the output, not good for audio use)
DAC8811 (CPLD data input) (result: audible digital noise on the output, sound far away from very good audio, don't waste time and money on such DACs)
...
Attachments
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Have you listened to it without the 4n7s on the outputs of the OPA627s? I'm curious how they affect the SQ.
C37, C38 can be omitted, it is just a simple RC filter on the output (about 330kHz cut-off frequency), my AD1862 is without RC filter
if such a filter is not here after DAC, it will be present at any amplifier input (if not manually removed) 😀
the sound is affected by the capacitor type, it is least affected by the type of PP and C0G (SMD) (they have the lowest THD of all capacitor types)
if such a filter is not here after DAC, it will be present at any amplifier input (if not manually removed) 😀
the sound is affected by the capacitor type, it is least affected by the type of PP and C0G (SMD) (they have the lowest THD of all capacitor types)
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I wasn't thinking about distortion caused by cap type (I assumed NP0). Rather loading on the opamp output at higher frequencies. Filters at the input of amps generally have higher valued Rs than 100ohm before shunt caps. And have lower values of caps (1n would be about the highest I've seen).
right, it has to be omitted, or the value with resistor can be changed easily for any combination 🙂
there are many different tupe output stages, that's why I left the basic opamp with the possibility of Iout for any tube stage ... likewise, power supplies are not on the PCB because everyone prefers something different ... it is only a purely basic solution of the DAC module with endless expansion possibilities
Hi Miro1360, looks like Pavouk works.
I would suggest you look for the opa861 i/v stage of P Rogic in order to adapt it for the AD1862 or for a discrete stage with BC550/560 * sorted out to putt the I/V resistor at the end and choose a cool one : bulk or damped wirewound in case with a styren as decoupling of a good quality as you like NOS. If needed choose a cool oap for the buffer or a discrete two composant stage.
just my two cents. This chip diserve such cares.
* BC560 are now hard to find, but the smd casing is a possibility.
I would suggest you look for the opa861 i/v stage of P Rogic in order to adapt it for the AD1862 or for a discrete stage with BC550/560 * sorted out to putt the I/V resistor at the end and choose a cool one : bulk or damped wirewound in case with a styren as decoupling of a good quality as you like NOS. If needed choose a cool oap for the buffer or a discrete two composant stage.
just my two cents. This chip diserve such cares.
* BC560 are now hard to find, but the smd casing is a possibility.
As i wrote above, people can try different I/V designs. I/V is another chapter.
My intention was not to modify the sound of the AD1862 in any special way (what can be done by I/V).
Iout is present and therefore everyone can connect any converter. Do you know how many good converters are there? including tubes ... life is short to test them all and find the best one 🙂
My intention is simplicity, not to limit it to a complex PCBs and then through complex adjustments find the right sound 😀
Pavouk website is nice source of DAC designs. He tested many different R-2R DACs, but he did not tried AD1862 ... he could finally 😀
The schematic of AD1862 is from datasheet, I/V is a simple opamp standard,
shift register part - I don't know who implemented it first .. it's no magic, it's just a bit shifting ...
Eric Juaneda did a lot of work on the shifter:
High End Audio - Digital decoder for NOS DAC
than DDDAC did a lot:
DDDAC 1794 NOS DAC - Non Oversampling DAC with PCM1794 - no digital filter - modular design DIY DAC for high resolution audio 192/24 192kHz 24bit
there was an universal shifter I2S to PCM, a few years ago, I can't find the link ...
I could use the stop clock method with no additional benefit ... many options where to go ... I found this most user friendly, because only SOIC chips are needed and anyone can solder it.
My intention was not to modify the sound of the AD1862 in any special way (what can be done by I/V).
Iout is present and therefore everyone can connect any converter. Do you know how many good converters are there? including tubes ... life is short to test them all and find the best one 🙂
My intention is simplicity, not to limit it to a complex PCBs and then through complex adjustments find the right sound 😀
Pavouk website is nice source of DAC designs. He tested many different R-2R DACs, but he did not tried AD1862 ... he could finally 😀
The schematic of AD1862 is from datasheet, I/V is a simple opamp standard,
shift register part - I don't know who implemented it first .. it's no magic, it's just a bit shifting ...
Eric Juaneda did a lot of work on the shifter:
High End Audio - Digital decoder for NOS DAC
than DDDAC did a lot:
DDDAC 1794 NOS DAC - Non Oversampling DAC with PCM1794 - no digital filter - modular design DIY DAC for high resolution audio 192/24 192kHz 24bit
there was an universal shifter I2S to PCM, a few years ago, I can't find the link ...
I could use the stop clock method with no additional benefit ... many options where to go ... I found this most user friendly, because only SOIC chips are needed and anyone can solder it.
Sorry i didn't see you chose the internal V outputt of the chip.
Pavouk tried the ad1865 Hardware
opa861
is simple, in fact way simplier as it can be seen like a single transistor !
In fact many the I/V can be the same than the internal voltage stage but with better part and it"s a proven fact it sounds best, in others words the voltage output is worse... or maybe it is the ad1865... you know memory and ears 😉
Iancanada said one or two things as well on register iirc. especially about the best in order to data signals
In fact I tried both with this chip voltage and curent and I can tell you the curent output will give yo more of good sound (take it or not of course is your freedom=) or was it the ad1865 you know memory...did I wrote this already ?
Tip if simple is wanted : dc converter heps a very simple way to power the chipto have the best of the voltage outputt
well one can make as simple without more work.
soic : DIR9001 SPDIF decoder or toslink a la ecdesign or USB...
Me lurk about the headphone buffer possibility 🙂
Pavouk tried the ad1865 Hardware
opa861
is simple, in fact way simplier as it can be seen like a single transistor !
In fact many the I/V can be the same than the internal voltage stage but with better part and it"s a proven fact it sounds best, in others words the voltage output is worse... or maybe it is the ad1865... you know memory and ears 😉
Iancanada said one or two things as well on register iirc. especially about the best in order to data signals
In fact I tried both with this chip voltage and curent and I can tell you the curent output will give yo more of good sound (take it or not of course is your freedom=) or was it the ad1865 you know memory...did I wrote this already ?
Tip if simple is wanted : dc converter heps a very simple way to power the chipto have the best of the voltage outputt
well one can make as simple without more work.
soic : DIR9001 SPDIF decoder or toslink a la ecdesign or USB...
Me lurk about the headphone buffer possibility 🙂
opa861 output stage can be build separately.
AD1865 is current output too, but it has the possibility of Vout using internal opamp (it sounds not very good, as you already tested). AD1862 is higher lever, more complex architecture.
AD1862 has not Vout, it is current output.
AD1865 is current output too, but it has the possibility of Vout using internal opamp (it sounds not very good, as you already tested). AD1862 is higher lever, more complex architecture.
AD1862 has not Vout, it is current output.
told you... my memory !
go try the opa861, tell me then (yes it's good, jus care as it can oscilllate)
go try the opa861, tell me then (yes it's good, jus care as it can oscilllate)
here is 4-layer PCB: easyDAC = NOS R-2R AD1862 DAC + Headphone Amp
you can omit some parts that you don't need
if there is more interest, I can create SMD version as well in the same way as this THT
But as diyiggi wrote, THT is trouble-free, the sound still be great
you can omit some parts that you don't need
if there is more interest, I can create SMD version as well in the same way as this THT
But as diyiggi wrote, THT is trouble-free, the sound still be great
Hi Miro,
Is it a 4 layers ? I have to try it then. Any good company not to expensive where I can send your gerber and Europe based please ?
Is it a 4 layers ? I have to try it then. Any good company not to expensive where I can send your gerber and Europe based please ?
Yes it is 4 layers. Europe based company? They are overpriced for me and therefore, I have no experience with them. For me, the best option is jlcpcb, very high quality, best price for EU (even though manufactured outside the EU), shipping is fast and I am sure you will get it under 20€. This is not an advertisement because I'm not associated with them in any way - just best experience and quality I found yet, if the brands and names of any parts can be mentioned, then I think it doesn't matter. The calculator on their website gives a price for this 4 layer PCB of around 7€ for 5pcs, shipping is similiar.