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

Member
Joined 2007
Paid Member
@tubee, great to hear!

I have one Pi3, which does not spill out i2s with volumio as well (the others do) , and I have no idea, why. This pi fooled me with 2 different DACs until I found out by use of an USB board, that the DACs were OK.

Yesterday I boxed my AD1862 DAC. I rearranged it a little and cleared the DC as well as the signal cables; maybe some remember the photo of my cable grave. I was floored by a the unexpected improvement, this made :wow: And I am curious, if shortening the i2s lines makes a step again.

Cheers, Ernst
 
Last edited:
Hi Ernesternest

Yes for some reason I did not get signals on i2s pins in volumio nor raspbian nor twister. It must be a solution in some terminal-commands but could not figure out what.
After all got it working in Moode! And like it a lot.

ATM listen to it and swapped the dull LM6171 for my favourite THS4031 and man this thingie is now starting to sing!
 
Member
Joined 2007
Paid Member
@tubee,

I will try Moode as well with this Pi. Up to Moode 4 I used Moode only, but then issues occured and I was not willing to compile new versions again and again. So I moved to Volumio, which always served well with other Pi models.

I liked the LM6171 very much in the EASY DAC. In this one I haven't heard it, as the V6c satisfies my needs in a pretty good manner. Yet there are always options for trying.

Cheers, Ernst
 
You can pull ths4031 in class a did it before but not with a ths4031/32
Advisable is to put it on a small heatsink, the 4031 is getting warm already for some extend.
They are only available in soic so you need a soic to dil adapter board for them.
Opa627 is on its way, but also heard from another dac builder the AD744 should be a good performer

Yes I/v opamp should be fairly fast because of hf signals it has to process. Fast chips on the other hand need proper decoupling!

@miro no, stuck with ths4031/4032 as I/v
Will try you suggested faster THS3001 too, but ultimate plans are with tubes(in time haha)
 
Last edited:
Vunce, add also THS3001, as it is from that family, although different topology (really very fast topology, I/V should be very happy with that tho :D)


So not on adaptators but on the soic version :) soldered directly... with some nice smd trace for 0805 caps ;) with vias on the trace for THT (through holes) .


My thoughts to improve all the good nwork already made,
which is not a surprise as it's an old song from me :


It deserves a pcb per oap AND a two stage to split the I/V from the next stage if needed to drive/color the next stage, which is involving :


- a pcb with soic single and double oap
- a pcb with soic simple towards double oap stage as buffer
- a pcb with double soic towards double oap and single oap stage as buffer
- same as above with DIP8
- a special for the oap861


Only trade off being made on the AD1862 adaptor :eek:



:) Dunno if someone can do that from Miro's gerber. :confused:



Adaptator are questionable with fast oaps :D


All of this, more than a dac could be a fantastic tweak learning school, I dunno pcb were so affordable nowadays :)
 
Last edited:
Member
Joined 2014
Paid Member
Vunce, add also THS3001, as it is from that family, although different topology (really very fast topology, I/V should be very happy with that tho :D)

Those THS3001 are pricey buggers! If my cart doesn’t hurt to much I will add them also. ;)


So not on adaptators but on the soic version :) soldered directly... with some nice smd trace for 0805 caps ;) with vias on the trace for THT (through holes) .

Good suggestions Iggy, especially for the THS3001. I would use the revised boards with the SMD opamps, no adapter.



....ATM listen to it and swapped the dull LM6171 for my favourite THS4031 and man this thingie is now starting to sing!

In your opinion (and system) you prefer the the THS4031 over the LM6171? That’s impressive, I like the LM6171 in my setup, now I must continue the opamp swapping :D

Enjoy!!