Soekris Dam Dac

[randytsuch]

New DIY ladder R-2R dac.

Long thread about it here, but most of the thread is before anyone actually got the DAC.

http://www.diyaudio.com/forums/vendors- ... 4-khz.html

I got one late last week, Europeans who ordered early got it about a week before that.

There are at least a couple other guys here who I think are building DAC's based on this.

As DIY projects go, it should not be too hard.
Need to supply it power, easiest way is to connect a dual secondary transformer, but you can also supply +/- 12VDC and get more exotic with the power supply.

It uses op amps for the output, but I think you can bypass.

Some early comments look promising.

So, I decided to start a thread here to discuss.

Randy

[nige2000]

i got one of these
its quite a nice board
ill probably let it burn in before i take the soldering iron to it
it may be cheap for a ladder dac and fifo reclocker but its still expensive i really dont want to break it

powered it up roughly with an ac input to test it
i wasn't immediately disappointed which is always good

[randytsuch]

Hifiduino generated a nice summary of how to get the dac going:
https://hifiduino.wordpress.com/

He pulled it out of the thread so you don't have to search 1000 posts to find it.

And a word of warning.
I think I've seen two guys who have blown equipment.
One guy said he lost the ground to the volume control pot, and it went full volume and blew his speakers.
The kind of problem you get in prototype mode, once this is installed in a chassis you shouldn't have this happen.

Another guy blew his amp because he turned off the dac before the amp, and when he turned off the dac it sent a large pulse to his amp.

To me, this second scenario is more dangerous. As a habit, amp is the first thing I turn off, and the last thing I turn on, but sometime you mess up. Hopefully they can update the firmware to provide better protection for this type of thing.

Randy

[rickmcinnis]

One wonders what would happen with a power failure?

Would the amps "turn off" in time to miss the pulse?

Also,dimdim has started a blog. He shows how to load firmware updates whcih I had no idea how to do. I suspect he will add more bits of useful information as he goes along. http://www.dimdim.gr/

Starting with transformers but looking forward to nige2000 showing the way with battery supplies!

Wish the +- 4 volts supply was 3.3 volts!

[nige2000]

tested with amanero self powered + ac power vs jk cuinas because im very familiar with it

r2r dac is more detailed
gut feeling that noise floor, reverberation, decay, highs and speed can be improved with ps mods

will get the dual mono 1794 dac up and running again and see how that goes:)

[randytsuch]

Nigel,
Are you using the opamp output from the DAC?

I have a tubed output stage designed for the DAC END dac I bought a little while ago, may try that.
In the ES9018 dac I listen to now I have a zapfilter II output stage that I could move over, but I'd rather keep that DAC in tact for a while.

Rick
Power failure is a good point, although for me it's rare enough so that wouldn't be my top concern. Amps usually have a lot of capacitance, so they take a little bit to turn off, so I would guess there might be an issue, wouldn't want to test it.
I'm surprised a guy blew an amp though, I would think blowing speakers (or headphones) would be more likely.
Since there are a bunch of guys at diyaudio building these dacs, if Soeris doesn't come up with something maybe somebody else will figure out a simple protection scheme.


Randy

[nige2000]

no opamp tested yet


a-b tested
lifepo4 powered amanero into ac powered dam dac against my lifepo4 powered dual mono pcm1794

it is clear the ps system is holding the dam dac back

i know the dam dac has to burn in yet but in their current configurations i would prefer the 1794

will try 12v dc batteries next

[rickmcinnis]

No surprises there.

It is amusing that over at DIYAudio where SOEKRIS and his DAC are being worshipped as a god by a few of the easily excited. I ask a question about batteries and in no time there is talk of snake oil and how perfect SOEKRIS's power supplies are. Instead of reminding these true believers (in the latest thing) that this is a very reasonably priced device and at its price there is not a chance the supplies are as good as they can be.

Even with SOEKRIS's warning that the board could be burned up with 18650s (which is in fact perfectly possible!) I look forward to nige2000 or some other intrepid soul finding out how to get past these perfectly realized regulators and hear what this thing just might be capable of.

Two more days ...

Randy, my amps have modest cap banks so I feel sure I would not have a problem with turn off. Now thirty years ago when I was SURE than audio nirvana could be had for the cost of surplus cans and some wire. When the lights dimmed at amp turn on - that has to be good, right? I might have had some problems. I was asking more theoretically - wondering is a a quick BLURT or something more long lasting?

Yeah, the amp and speaker blowing stories did seem a little ... fantastic.

[nige2000]

No surprises there.

It is amusing that over at DIYAudio where SOEKRIS and his DAC are being worshipped as a god by a few of the easily excited. I ask a question about batteries and in no time there is talk of snake oil and how perfect SOEKRIS's power supplies are. Instead of reminding these true believers (in the latest thing) that this is a very reasonably priced device and at its price there is not a chance the supplies are as good as they can be.

it is an excellent dac
oob it sounds good its just a shame no provision were left to use custom power solutions
need to remove the regs/electrolytic caps
1.2v switch mode reg should be ok if powered from lifepo4
+/-4v is a pinta to high for one cell and two low for 2
i have run one cell at 4v before but it cant be a great idea
f sake 3.3v would have been nice if it were the r ladder v
two cells would have more than likely done everything then

Even with SOEKRIS's warning that the board could be burned up with 18650s (which is in fact perfectly possible!) I look forward to nige2000 or some other intrepid soul finding out how to get past these perfectly realized regulators and hear what this thing just might be capable of.

ANR26650 would be preferable to 18650's
the problem is the risks it only take a simple mistake

[randytsuch]

No surprises there.

It is amusing that over at DIYAudio where SOEKRIS and his DAC are being worshipped as a god by a few of the easily excited. I ask a question about batteries and in no time there is talk of snake oil and how perfect SOEKRIS's power supplies are. Instead of reminding these true believers (in the latest thing) that this is a very reasonably priced device and at its price there is not a chance the supplies are as good as they can be.

Even with SOEKRIS's warning that the board could be burned up with 18650s (which is in fact perfectly possible!) I look forward to nige2000 or some other intrepid soul finding out how to get past these perfectly realized regulators and hear what this thing just might be capable of.

Two more days ...

Randy, my amps have modest cap banks so I feel sure I would not have a problem with turn off. Now thirty years ago when I was SURE than audio nirvana could be had for the cost of surplus cans and some wire. When the lights dimmed at amp turn on - that has to be good, right? I might have had some problems. I was asking more theoretically - wondering is a a quick BLURT or something more long lasting?

Yeah, the amp and speaker blowing stories did seem a little ... fantastic.

I had the same thoughts when I read the diyaudio response to your question about alternate power supply.
How do you know if you don't try?

That is why I decided to start a thread over here. Experimentation is encouraged instead of questioned.
I am thinking good linears may be the answer since 4V doesn't work for lifepo4 for the reasons Nigel gave.

Randy