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

Good news is my SPDIF/Optical board works - get data, lrclk and bclk signals on the scope

Bad news is the DAC doesn't work.... need to trace some stuff out. Got power in all the right places, but data isn't getting through. Time to see what I can find with the scope. Expect I messed something up on the 74HCT164D somewhere

When I connect the DAC to the I2S board the LRCLK signal is still good. But the other 2 signals drop to zero/noise. So I am not sure what's going on at the mo. I've pulled the opamps and DAC chips out for now.
 
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Good news is my SPDIF/Optical board works - get data, lrclk and bclk signals on the scope

Bad news is the DAC doesn't work.... need to trace some stuff out. Got power in all the right places, but data isn't getting through. Time to see what I can find with the scope. Expect I messed something up on the 74HCT164D somewhere

When I connect the DAC to the I2S board the LRCLK signal is still good. But the other 2 signals drop to zero/noise. So I am not sure what's going on at the mo. I've pulled the opamps and DAC chips out for now.
Fixed it - had shorted 2 pins on one of the 74HCT164D underneath the chip with a blob of solder. What a muppet!

Better go and listen to this thing now!
 
First impressions spinning some of my regular test tracks. DAC sounds beautiful. Much better imaging over the standard DAC in both my Roksan K2 CD and Hifiberry DAC (RPi). I'd say a much better overall balance, slightly smoother treble than the others. Overall very good, was a worthwhile venture to get this far. Need to finish it off now and figure out how best to switch between the Optical and Coax inputs.

Rest of my system for reference is DIY VTA PH12 pre amp and ESP P101 MOSFET power amps with AE2 speakers.

Forgive the dodgy test layout.

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Hey folks, here's the beginning of a longwinded thread about different op amps in this DAC:

Burson sent me some V6 Vivid's to try out. I have high expectations.
 
Question for the collective. The SPDIF/optical input board has a jumper to select one or the other input. I really want to use both with 2 different sources. Can I fit a remote changeover switch given that this is in the digital signal path? It would be around 6" of cable to the switch on the panel.

Would it be better to build another input board and switch them with an I2S switch? I have the boards and components to do that, but if I could run less boards then I'd prefer that.

Flak,

It looks very nice. My AD1862 is on a board.

Thanks!
 
Question for the collective. The SPDIF/optical input board has a jumper to select one or the other input. I really want to use both with 2 different sources. Can I fit a remote changeover switch given that this is in the digital signal path? It would be around 6" of cable to the switch on the panel.

Would it be better to build another input board and switch them with an I2S switch? I have the boards and components to do that, but if I could run less boards then I'd prefer that.



Thanks!
Use a switch wired with shielded wire (it can be SATA cable or anything for HF) ... the shield must be connected with GND on one side (shielded wires near the switch are connected together) :)
Another option is can be relay as jimk04 suggested.
 

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@sworder84 I will quote your message and reply here:

>>By the way - where I can get a power supply board? I see is there are few different versions - which is best?
It depends. In my opinion, for audio is best something with an emitter folower stage with no gain, PSU1 with 78xx/79xx regulators offers it.

>>I also see I third board (LDO - why it need?)
LDO is for people who will test another regulators and compare it :D

>>As for my Akai - I have a few dozens CD and listen them. I also to compare with Unison Research Unico CDP (about 2500 Euro retail) and Akai is winner. I was changed all capacitors for digital part of Dac's on Silmic-2. I see a new digital filter but never buy it
Avoid DF1704 digital filter upgrade. DF1704 is crap, let your DAC with the "older" one (upgrade with PMD200 filter is good, but not cheap and can be hard to obtain).

>>I would very happy if this DAC would be an "other better level" in comparison with my sources!
My DAC can compete with best DACs, just DIY it for your needs :love:

>>I'd like to know - is the possibility to make a balance DAC? I have a balance amp.
You can do it with 2 PCBs and custom I/V (the second one has inverted DATA). Better if you let a preamp to make it balance (single to balanced output) or avoid balanced at all for a short distance if your amplifier has single input possibility.

>>Does Dac have a spdif (coaxial RCA input) except USB transport?
Yes, see the builds above. (or you can buy some spdif to I2S from aliexpress).
 
Use a switch wired with shielded wire (it can be SATA cable or anything for HF) ... the shield must be connected with GND on one side (shielded wires near the switch are connected together) :)
Another option is can be relay as jimk04 suggested.
Thanks very much! I'll give it a try and let you know how it goes. I have some spare SATA cables kicking around so will use one of those.
 
>>I'd like to know - is the possibility to make a balance DAC? I have a balance amp.
You can do it with 2 PCBs and custom I/V (the second one has inverted DATA). Better if you let a preamp to make it balance (single to balanced output) or avoid balanced at all for a short distance if your amplifier has single input possibility.

Here's something on the subject with links to opinions: Link

And have a look at figure 5b: Link

And Broskies Tube-Balancer: Link
 

Paddy Garcia

Member
Paid Member
2014-04-28 1:09 pm
Virginia USA
Famous last words: I might be done for a while :)

I've got a nicely tuned miro DAC system in my office, one for my dad, a kit packaged with a Whammy headphone amp kit to give to my son when he finishes his Masters this spring, and now one in the living room. I guess I could build one for the garage, but that seems excessive.

Here's the latest package, all follow the same pattern of a Miro DAC, a Pass DIY B1K preamp, Academy Audio Muses volume control, 3e 3255 class D amp, and power supplies. I tried in the past to cram all this into a single 19" chassis, but that's 10lbs of electronics in a 5lb sack. Here, the power supplies are packaged with the amplifier in one box, with the rest in a second box. Was going to put the DAC psu into the lower box but read here that the regulators should be close to the DAC, so there's a half a PSU in the lower box, rectified DC runs through the umbilical, and the other half upstairs.
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