Hello everyone.
I currently have a Dac End project dac that has been working quite well for several months and recently decided to up and quit on me.
While I am not 100% sure, I am thinking the dac chip probably died on me. Sadly the dac chip is an AD1865 chip and it is near impossible to get a genuine replacement.
I am wondering if there is a more modern R2R dac chip with current out. The only other Dac chips that I know of that will work would be the TDA 1543 or if I were to change the board design, the PCM1704. But both of those chips are just as hard to find as the AD1865 so it doesn't do me a lot of good.
----------------
I am also considering building my own resistor ladder. I know I would have to go through the hassle of getting a good bench multimeter that goes out to some ungodly number of digits to match the resistors well enough to get 16 bit resolution let alone 18 or 20.
However precision resistors will always be around and will only get better and cheaper in time. Going through the hassle of building a ladder once and maintaining it might actually be more feasible and less cumbersome than trying to sort through fake chinese r2r dac chips.
If anyone knows of a good R2R ladder dac schematic, I would love to see it
I currently have a Dac End project dac that has been working quite well for several months and recently decided to up and quit on me.
While I am not 100% sure, I am thinking the dac chip probably died on me. Sadly the dac chip is an AD1865 chip and it is near impossible to get a genuine replacement.
I am wondering if there is a more modern R2R dac chip with current out. The only other Dac chips that I know of that will work would be the TDA 1543 or if I were to change the board design, the PCM1704. But both of those chips are just as hard to find as the AD1865 so it doesn't do me a lot of good.
----------------
I am also considering building my own resistor ladder. I know I would have to go through the hassle of getting a good bench multimeter that goes out to some ungodly number of digits to match the resistors well enough to get 16 bit resolution let alone 18 or 20.
However precision resistors will always be around and will only get better and cheaper in time. Going through the hassle of building a ladder once and maintaining it might actually be more feasible and less cumbersome than trying to sort through fake chinese r2r dac chips.
If anyone knows of a good R2R ladder dac schematic, I would love to see it
Hmmm. Well for starters its a delta sigma dac, but I am noticing that its kind of the same deal with the AD1865. All the sources on ebay are from china.
I am really tempted to get something like this. AD AD1865N-K DIP-24 Complete Dual 18-Bit 16 3 FS Audio DAC | eBay
But I too do not know how to check if something like this is fake or not which is part of my hesitation for getting these chinese ebay chips.
Nope, its not delta-sigma, though strictly speaking is not R2R either. Yes all the sources are from China, does that mean they're all fake? How would one go about faking such an inexpensive chip though? I reckon the proof of the pudding is in the eating, so if the chip sounds great then does its provenance matter much?
True, fair point. I will get a couple. If nothing else I can use them for a different project and keep a small stock.
Actually, getting a genuine replacement is very easy if you know where to look.
Rochester Electronics has hundreds of new, never used, AN1865 chips, all grades, PDIP and SOIC, in stock, for sale in quantities of 1 to 1000+, at reasonable prices.
Yeup. I already know about these guys, but they have a minimum order quantity of 6. I have a group buy going, but no one is biting.
go with AD1862 or PCM1704, you can consider PCM1702 (but here I have no experience)
... you are talking that ebay AD1865 are fakes, actually they are not fakes - they are genuine and are digged out from old devices (during recyclation process), you can use DIP chips without problems, strictly avoid SMD chips because SMD are digged out with hot air machines and it will degrade chips (PCM1704 from ebay) ...
you can be fine with AD1865, AD1862, PCM1702 in DIP package from ebay ...
... you are talking that ebay AD1865 are fakes, actually they are not fakes - they are genuine and are digged out from old devices (during recyclation process), you can use DIP chips without problems, strictly avoid SMD chips because SMD are digged out with hot air machines and it will degrade chips (PCM1704 from ebay) ...
you can be fine with AD1865, AD1862, PCM1702 in DIP package from ebay ...
Last edited:
or if you aware about genuity so much, there still be last source of R2R chip available, it is this one:
Rochester Electronics
: Part AD1862N
... or alternatively you can looking for PCM1704, sometimes they are available too from trustable source, like this one:
Rochester Electronics
: Part PCM1704U-J
...
Rochester Electronics
: Part AD1862N
... or alternatively you can looking for PCM1704, sometimes they are available too from trustable source, like this one:
Rochester Electronics
: Part PCM1704U-J
...
Another intriguing option is the still in-production 16-bit PCM56. This chip has been extensively tested and advocated by diyaudio contributor 'Bernhard', who claims that spectrum analyzer measurement reveal it exhibiting superior linerarity to about every other R-2R audio DAC chip, including those of greater bit depth (FYI - I do not have personal experience with the PCM56).
Although not exactly cheap (about $25 ea. in small quantities via Digikey.com and mouser.com) they are much less expensive than the currently in-vogue discrete R-2R modules. Again, the PCM56 is still in-production and readily available from those factory authorized distributors.
PCM56U Texas Instruments | Integrated Circuits (ICs) | DigiKey
Although not exactly cheap (about $25 ea. in small quantities via Digikey.com and mouser.com) they are much less expensive than the currently in-vogue discrete R-2R modules. Again, the PCM56 is still in-production and readily available from those factory authorized distributors.
PCM56U Texas Instruments | Integrated Circuits (ICs) | DigiKey
Thanks for the heads up.
God dang it. It looks like I need to make a bunch of new dacs and see which one I like the most. Sorry wallet : P
I am still very tempted to buy a bench top multimeter and start hand matching some precision resistors to make my own ladder dac. I would never need to worry about parts being in or out of production and I could have better control over the sound quality.
But I am also looking at changing my IV stage. Right now I am using some 417as and they aren't the quietest things in the world. I am seeing 2mv noise floor just from the tubes lol.
Why not keep an eye out for faulty cd players with the dac chip you need and buy one for the parts?
Could work out the same cost and you know the parts would be genuine.
I have bought DAC chips from an ebay seller in china, they worked.
He removes them from old equipment.
I am not sure if I can post the link here?
Could work out the same cost and you know the parts would be genuine.
I have bought DAC chips from an ebay seller in china, they worked.
He removes them from old equipment.
I am not sure if I can post the link here?
Cause I am not a CD player guru and I have no clue which cd players have which chips.
I do eventually want to build my own CD player though, sooooo that might not be such a bad idea.
I have a question, how do you "fake" an AD1865 except by simply selling a rebranded same package random part. My idea of fake is a part that plugs in and functions like the original, almost. This is easy with op-amps and JFET's, far less so with DAC's and virtually impossible with ADC's.
Well it looks like I can post the link here.
https://www.ebay.com.au/itm/1pcs-AD...848601&hash=item1a493e4914:g:GxwAAOSwLe5auxHy
1PCS AD1865N-K Complete Dual 18-Bit 16 x Fs Audio DAC AD1865N | eBay
1 X AD1865R-J SOIC28 TO DIP24 Complete Dual 18-Bit 16 x Fs Audio DAC AD1865N-J | eBay
I have bought PCM63 and PCM1702 dac chips from this seller and they worked. The PCM63 were still on the board I removed them myself the PCM1702 were new.
You can also check his feedback.
For a list of cd players and their DAC Chips see this link, I think the AD1864 is pin compatible.
Hope this helps.
https://www.ebay.com.au/itm/1pcs-AD...848601&hash=item1a493e4914:g:GxwAAOSwLe5auxHy
1PCS AD1865N-K Complete Dual 18-Bit 16 x Fs Audio DAC AD1865N | eBay
1 X AD1865R-J SOIC28 TO DIP24 Complete Dual 18-Bit 16 x Fs Audio DAC AD1865N-J | eBay
I have bought PCM63 and PCM1702 dac chips from this seller and they worked. The PCM63 were still on the board I removed them myself the PCM1702 were new.
You can also check his feedback.
For a list of cd players and their DAC Chips see this link, I think the AD1864 is pin compatible.
Hope this helps.
You silk screen a AD1865n-J (or worse) as an N-k, you sell a dead chip as working (which I have experienced), or you literally sell a fake chip (nothing in it) which I have heard about.
Different ideas of fake. What you describe is simply fraud, there are no cheap equivalents with poor specs that can be rebranded like op-amps and JFET's.
You can certainly hand match resistors with a 5 digit DMM but the bigger issue is one of temperature coefficient. As far as I'm aware the best resistors get to around 5ppm/oC. You might want to explore putting your R2R array into an oven to keep the values stable (I think Dan Lavry might have used an oven in one of his DACs, can't remember). You also have to ensure that soldering the resistor doesn't cause the value to change.
Having just modified my own I/V stage (fed from TDA1387) I'd say this avenue is much more promising in terms of returns per hour spent than building your own R2R...
Hi,
Call me crazy, but I don´t think these PCM56 are fakes. Not sure though. I didn´t buy any.
The seller also has PCM56 in other grades and procendences (korea rather than japan). I remember the experts on PCM63 discussing different grades and origin of chips here at diya.
-Alex
5PCS Audio D/A Converter IC BB DIP-16 PCM56P-K PCM56PK PCM56P-KG4 MADE IN JAPAN | eBay
Call me crazy, but I don´t think these PCM56 are fakes. Not sure though. I didn´t buy any.
The seller also has PCM56 in other grades and procendences (korea rather than japan). I remember the experts on PCM63 discussing different grades and origin of chips here at diya.
-Alex
5PCS Audio D/A Converter IC BB DIP-16 PCM56P-K PCM56PK PCM56P-KG4 MADE IN JAPAN | eBay
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.