So, all good now I've added the second 4K7 config resistor - I've just been listening to a selection of music with the DAC set up on the bench - listening via headphones and my Noir HPA.
Initial impressions are a bit mixed, the mid-range is very easy to listen to and the bottom-end is deep and tight but there's a little hardness/tizziness right at the top. Maybe a bit of burn-in or perhaps some op-amp rolling might help, time will tell. Current op-amps are LM6171.
To make it work with the JLSounds V2 it just needs 4K7 resistors between pin1/pin3 and pin1/pin4 - no other configuration required. When I did my own PCBs to stack onto the JLSounds I actually included both the config resistors so my bad for forgetting about it. For my own implementation, because I already had short header pins soldered to the JLSounds, I did a little surgery to the 'flipped' board to allow clearance of the USB socket. You can see how I implemented the second config resistor below (I couldn't find a lower-rated 4K7 resistor in my spares so it's a bit big, but works fine of course).
Initial impressions are a bit mixed, the mid-range is very easy to listen to and the bottom-end is deep and tight but there's a little hardness/tizziness right at the top. Maybe a bit of burn-in or perhaps some op-amp rolling might help, time will tell. Current op-amps are LM6171.
To make it work with the JLSounds V2 it just needs 4K7 resistors between pin1/pin3 and pin1/pin4 - no other configuration required. When I did my own PCBs to stack onto the JLSounds I actually included both the config resistors so my bad for forgetting about it. For my own implementation, because I already had short header pins soldered to the JLSounds, I did a little surgery to the 'flipped' board to allow clearance of the USB socket. You can see how I implemented the second config resistor below (I couldn't find a lower-rated 4K7 resistor in my spares so it's a bit big, but works fine of course).
@nautibuoy Glad to see it working now 😉
Change the yellow tantalum capacitors for something other (like electrolytic nichicon ufg or ukz) ... these tantalums are not good choice for DAC in general (even though they are recommended in many datasheets -- even my initial schematic considered it, but it turned out that a good electrolyte is better) ... it can have impact on the sound 😊
One such tantalum exploded in my setup without any warning ... just explosion out of nowhere and everything worked also after the explosion (no oscillation or anything bad) 🤣 such an explosion is as dangerous to the eyes as a small grenade 😱
Change the yellow tantalum capacitors for something other (like electrolytic nichicon ufg or ukz) ... these tantalums are not good choice for DAC in general (even though they are recommended in many datasheets -- even my initial schematic considered it, but it turned out that a good electrolyte is better) ... it can have impact on the sound 😊
One such tantalum exploded in my setup without any warning ... just explosion out of nowhere and everything worked also after the explosion (no oscillation or anything bad) 🤣 such an explosion is as dangerous to the eyes as a small grenade 😱
Hello all, I measure oscillations on the -12V (Pin 2) of my AD1862 design. I've tried other regulators as well, tested with different decoupling.... nothing cures the oscillation completely. See attached document for what has been tested.
Question, can anybody post a scope picture when measuring between analog ground (pin 12) and -12V (pin2)?
Thanks in advance
Question, can anybody post a scope picture when measuring between analog ground (pin 12) and -12V (pin2)?
Thanks in advance
Hello everyone and Merry Christmas, I wanted to ask you if the diamond I/V stage in the photo is compatible with the AD1865 dac or does it need modifications? Is there a better/or more updated version? I want to replace my tube i/v stage to try something new. Which discrete i/v stage would you recommend?
Attachments
I ordered some Silmic RFS caps but they've not arrived yet so Tantalums are to get it going...
AD1865 is a DAC with a symmetrical output current +-1mA, thus no need to compensate any output offset. This means you can remove the Jfet and the 2 resistors mentioned on the right top of the shematic.
So it seems it DID remove Riv from the the dac board. ! I just redid the i2s lines to no avail. Have stripped the board out of the streamer to inspect as it's a bit crammed in, and I can see no R8/9. Result. Looks like I found the problem!
Riv reinstated. Still no dice. I have distortion/noise again over feint music but I can control the volume this time. Could I have damaged the OPA running without R8 and 9? I assume the noise I had before I reinstated the resistors was the opamps oscillating?
Opamps removed. Still no good. Buzzy crackly noise over the faintest trace of music. Either I've damaged the dac chips somehow or the i2s from the Pi/Fifo isn't working with the dac. Was fine with Abraxalito dac so I'm sure it shouldn't be an issue.
Thanks for the really nice tip, I found the I/V of euvl, but on the PDF the component values are not specified, and the GB is not active, so I don't know how to test this circuit.
Try running the DAC via USB interface XMOS, Amanero or JLSound, in my previous post I mentioned that TDA1541 does not like the signal from iPAD USB interface, and AD1862 DAC doesnt like 24 bit- 192KHz may be, just may be you might be facing the same problem. Although I am not clear about the reasons behind this weird behavior, you might give it a try.
Well it helps when you connect the i2s GND.! 🙄
Playing nicely now. Have set the Rpi not to upsample and it seems happy with 192/24 playing Mother Earth radio flac.
So a variety of weirdness going on, mainly operator error. But I'm not sure why it didn't play with the u.fl in the first place. Will revisit that.
Now I've proved it I can look at getting the Mori clocks and EUVL IV in there.
Playing nicely now. Have set the Rpi not to upsample and it seems happy with 192/24 playing Mother Earth radio flac.
So a variety of weirdness going on, mainly operator error. But I'm not sure why it didn't play with the u.fl in the first place. Will revisit that.
Now I've proved it I can look at getting the Mori clocks and EUVL IV in there.
