Listening to the I/V now and really like how it sounds. I was using the OPA1655 before. That is the opamp that I always seem to come back to in the AD1862. It just seems to do everything right.
I decided to build this I/V because I had some of the more expensive bits sitting in the parts bin. Things like tube sockets, 10uF caps, and of course the tubes. It was a no brainer. Right now I'm using a 6N23P-EV tube right now. I may give the 6DJ8 Amperex Bugleboy a try in the future.
I may want to give my PMC63 a try with the tube I/V. I know that I will need to make a change to a resistor and cap though.
Thanks again this has been a great thread with great people!
I decided to build this I/V because I had some of the more expensive bits sitting in the parts bin. Things like tube sockets, 10uF caps, and of course the tubes. It was a no brainer. Right now I'm using a 6N23P-EV tube right now. I may give the 6DJ8 Amperex Bugleboy a try in the future.
I may want to give my PMC63 a try with the tube I/V. I know that I will need to make a change to a resistor and cap though.
Thanks again this has been a great thread with great people!
After building AD1865, AD1862, TDA1540, TDA1541 and having few other option ind the Sigma Delta side I was thinking of making one around PCM1704, I understand that the chip is beyond obsolete at TI.
However a simply query at google results in insane amount of inventory, bit confused though the i came across another forum audiophilestyle and some of the posts suggested that although the chip may carry PCM1704 on it but inside may well be a sigmaDelta.
Inventory at digipart
My understanding is that if it is pin compatible with the original and functions the same then it may well be from the same die as the original albeit with lower quality and tolerance.
Or it may be the same case as those Sanyo Thick film hybrid ICs carrying STKxxx numbers, originals were something else but the ones available now if you break the protective coating you'll find SMD parts inside.
Any comments, please, before I decide to buy some?
However a simply query at google results in insane amount of inventory, bit confused though the i came across another forum audiophilestyle and some of the posts suggested that although the chip may carry PCM1704 on it but inside may well be a sigmaDelta.
Inventory at digipart
My understanding is that if it is pin compatible with the original and functions the same then it may well be from the same die as the original albeit with lower quality and tolerance.
Or it may be the same case as those Sanyo Thick film hybrid ICs carrying STKxxx numbers, originals were something else but the ones available now if you break the protective coating you'll find SMD parts inside.
Any comments, please, before I decide to buy some?
Pcm1704 is not delta sigma. It is r2r sign magnitude dac. To most that built and listened to it, sounds dry comparing to ad1865 ad1862.
Hello,
Is there a Bom for michelag's tube i/v ? I already found the Gerber files and the trafo link - cannot find the bom.
Many thanks
Is there a Bom for michelag's tube i/v ? I already found the Gerber files and the trafo link - cannot find the bom.
Many thanks
The gerbers can be found in post 8,353
https://www.diyaudio.com/community/...s-input-nos-r-2r.354078/page-418#post-7710269
The schematics and BOM can be found in posts 8,261 and 8,267
https://www.diyaudio.com/community/threads/dac-ad1862-almost-tht-i2s-input-nos-r-2r.354078/page-414
https://www.diyaudio.com/community/...s-input-nos-r-2r.354078/page-418#post-7710269
The schematics and BOM can be found in posts 8,261 and 8,267
https://www.diyaudio.com/community/threads/dac-ad1862-almost-tht-i2s-input-nos-r-2r.354078/page-414
C4 and C10 are Wima MKP or MKS 1uF 50 or 63V. Forgot to update the BOM.
If you need bare boards, I can ship PSU and audio at shipping cost (from Germany)
Let me know.
@rehanabid Avoid buying PCM1704 from any website. Everything legit is sold out and only scrap from electronic waste is left. Problem with PCM1704 desoldered from electronic waste is either not working chip or highly degraded. The only option is to buy some old player or DAC that contains this chip and do the desoldering at home carefully using low temperature solder wire 😎
@rehanabid PCM1704 like this is good deal: https://www.ebay.com/itm/235508755108
Desoldering carefuly with low melt solder 🙂 (or do not desolder, use it as is, but disconnect filter or connect data after the filter)
Desoldering carefuly with low melt solder 🙂 (or do not desolder, use it as is, but disconnect filter or connect data after the filter)
@passive420
Thanks for your adapter board and AD1865. Works perfectly. Letting the chip warm up for next couple of days.
Thanks for your adapter board and AD1865. Works perfectly. Letting the chip warm up for next couple of days.
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😉 If I talk about it objectively based upon need, then no I dont need another one.🙂
But this is one way of keeping my mind occupied.
I know my sentence did lack punctuation and might have led to an understanding that I am confusing PCM1704 with a delta sigma, but I know its the last one R2R 24bit/96KHZ.
Thanks though.
Thanks @miro1360 I did buy old CD players and pulled couple of excellent DACs like AD1862, PCM1704 (one pair) but its always good to have a backup.
Instead of de-soldering I usually pull the chips through laser CNC cutting of the PCB fine tuned to mm, this way I usually get the chip without exposure to heat for a longer period of time.
ebay link looks good. My experience of buying DAC chips (PCM56, and a few other) compared to pulling them out of old CD players, there is remarkable difference in sound quality between both. Ones pulled from old players tend to be much better/smoother.
BTW: did anyone try to interface TDA1540 with one of VLSI chips?
Back trying to make my DAC work.
Though there is signal on pins 5,6,7 (bck, lock, data), and voltages are ok, I see on the scope a flat line out of pin 11. For both. Also after the I/v resistor. Flat line.
Tube CCS is working though, applying a signal I get music.
How to test ad1862 stand alone?
Thanks
Though there is signal on pins 5,6,7 (bck, lock, data), and voltages are ok, I see on the scope a flat line out of pin 11. For both. Also after the I/v resistor. Flat line.
Tube CCS is working though, applying a signal I get music.
How to test ad1862 stand alone?
Thanks
@rehanabid it's all there, at this point I suspect I burned the two DACs (at the same time? Quite strange?)
This are the resistances I measure.
Has someone a couple 1862 to sell? 😭
This are the resistances I measure.
Has someone a couple 1862 to sell? 😭
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