DAC AD1862: Almost THT, I2S input, NOS, R-2R

> When your eyes and hands are as old as mine you'll take all the help you can muster...

Even Jan Didden can solder 0603 after some practice.
So I am sure you can, if you want to.

> If you can hand solder them they should be fine with a reflow.

The PCBs are not designed with PCB software.
The pads are not always symmetrical.
So if you want to reflow, you do it at your own risk.

Or you design your own board.
Simple enough.


Cheers,
Patrick
 
You can buy pre-soldered LT3045 and LT3094 boards on ebay and the like that I think will work. They will not be quite as neat as the ones EUVL had assembled, but it will work nonetheless. You can probably buy those boards assembled for less than you can buy the parts for. There is always the worry about fakes - as always it is your own individual choice what to do.

I don't know what to say on the matching - on one hand it makes sense to buy a larger batch and match sets from it, make a simple test rig and that maybe gives an economic way of getting as close as possible sets, but on the other hand matching large numbers is very time consuming and tedious. So no guarantees on that from me at least, but lets see.

fran
 
The schematics is published, so are the photos.
So why not design your own PCB, make a prototype, do the measurements and listening test.
Then send them around for other to listen.
Then publish your Gerber files here for free ?

I am all for that. I won't stop you.
The minute I published, I knew this could happen, as it had before.

And for all others who do not want to do SMD, Pedja's circuit has the same performance.
Easy to do P2P.

Incidentally, these Gerbers from me are also free :
FirstWatt J2
UDNeSS, or You don't need Semisouth's
Geoff Moss's JLH-2005 design files


We have hijacked miro's thread long enough.
So I shall stop here.



Patrick
 
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0402 is possible by hand, with practice.

I guess if I practice enough I can be the next Lionel Messi too.

It's not that I don't want to do smd soldering, I do and I have with some larger components, but my eye/hand coordination isn't what it used to be when it comes to the tiny parts that are common today.

Anyway, the subject of this thread emphasises the through-hole nature of Miro's DAC project so perhaps adopting Pedja's circuit would be more in the spirit of the thread. I think I'll check it out.

Enough on smd soldering.
 
USB-I2S PCM2706 THT

Simple USB to I2S converter based on PCM2706.
- only 16-Bit and 44.1 - 48kHz
- native drivers (it can work under windows, mac, linux, android, raspberry, ...)
- transfer is synchronous (asynchronous is better)
- volume can't be set via windows volume control (only directly in a media player)
- don't use it with modern delta-sigma DACs (where the jitter matters as f**k)

It is almost THT, except for the PCM2706 chip.
How to solder this IC: youtube IC soldering

THT holes are quite narrow, so theoretically SMD 1206 components can fit there.
But I like and recommend THT components for a higher reliability.
Why THT everywhere? Just experience: Another dead DAC from SMD components on my table, where after 3 years an SMD capacitor retired and I can't find motivation for the repair 😀

USB connector can be any (connected with wires - USB cable).

Tested by me and works.

Components example, mouser:
R4, R5: 594-5043ED22R00F
R2, R3: 594-MBB02070C1501FC1
R1: 594-B0207C1M000F5T
C1, C5: 81-RCER71H104K0DBH3A
C2, C3, C4: 810-FA16X8R1H105KRU6
C6, C10, C11: 667-EEU-FS1H270
C8, C9: 81-RCE5C2A180J0A2H3B
Q1: 520-ECS120-18-4X-CKM
IC1: 595-PCM2706CPJTR
X1: 649-61729-1011BLF
X2: 649-1012938190802BLF
 

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@jean-paul ... experimentation is often a waste of time, people can compare sound with ready-made devices and write their opinions 🙂
I would like to create some USB-I2S for people, but unfortunately everything "better" is not very DIY. It's always easier to buy something ready-made, especially USB-I2S.
 
Miro,
You should have a look at ECDESIGN 's thread and also look at what made Maxlorentz from Chile as an adaptation of a low noise spidf... diy.

Unfornatuly, my feeling is a synchronous pcm2602, no galva isolation, smps high speed autobahn towards the ad1862 waste its quality despite it is said to be less sensible to jitter.

For not too much while true less diy, sd card a la Fran, reclocked stuffs, or usb xmoss chips, are mandatory for the good sound, ime.

While it's surely a good training and learning thing.
 
FYI today I tried 2 identical SD card players, with the exception that one has better NDK clocks on board. The difference was clear between both, with the better quality clocks clearly giving more resolution. Not a massive gain, but they all add up.

More experiments are underway. I think I have to try reclocking.
 
@jean-paul ... experimentation is often a waste of time, people can compare sound with ready-made devices and write their opinions 🙂
I would like to create some USB-I2S for people, but unfortunately everything "better" is not very DIY. It's always easier to buy something ready-made, especially USB-I2S.

Cheaper as well. The current devices have way better specs than the PCM27xx chips.