Construction of the final design
Is it difficult to build this DAC?
Is a question I get regularly, so lets spend a few words on it. Compared to the DDDAC1543mk2, this is actually easier to bring to a good end...
The DDDAC1543 needed some skilled soldering for the construction of the tower. This time there is no tower and as the SMD parts
are already pre-soldered on the boards, no long year experience is needed. Can an absolute rookie build this? Well I don't think so.
Some basic skills and tools are needed, let me sum them up.
- a good soldering station, not the typical hobby stuff you get in a home appliance market
- use thin wire solder
- at least a multimeter to check voltages
- recognizing components for what they are and know how to read or measure their values
- an understanding that working with main voltages (in case of power supplies) is dangerous
- make a neat solder point, which is not cracking or making short cuts to other solder joints
- reading the component print on the PCB
- have a good feel where the whole DAC fits in (PC, other equipment etc)
- understanding how to install software
Actually no extreme requirements, but in case you do not have all skills listed above, I suggest (if you still want to build the DAC ;-) you ask a good friend for help
or watch some videos on YouTube, or read a book about electronics or what ever. A compromise solution is to order the completely assembled boards.
Now you only need to hook them up to the outside world, which is clearly easier and has high chance of successfully ending this project...
In case you build my design, I ALWAYS help by email, or even repair service, in case of any problem. I want every DAC leaving my house
to play great music somewhere :-) Enough prelude.... have a look how I built my DAC. More pictures than words...
Relatively straight forward. Best practice is to start with the hex-spacers, so the board is no scratching on the surface of your work place.
Followed by soldering pins and pin headers (cut the 2x10 pin in half with a sharp knife or wire-cutter.
Use a tool to press them in the holes and solder them at both sides (!) Now solder the resistors, make sure the Rload resistors stand off a little bit.
Two reasons, better dissipation of idle power and in case you want more decks, easier to remove
or parallel with other values. Now is good time to do the LEDs. If you don't want them on the board (like front panel) just hard wire from here to the other location
Then, last but not least the capacitors and the voltage regulator.
Now connect the board to 12 Volts and check if 3.3 Volt is coming out of the Regulator and no smoke comes of any part. Just kidding
but it is better to check it now, than blow up the more expensive DAC Module (plus all the work to remove the deck again....
This can be a visual guide too. The Dales resistors are hard to read.
DAC Module (Deck)
Same as for the Mainboard, start with the small parts and end with the 47uF capacitors. The last ones must be really close to the PCB
and of course the polarity should be right...
Not much more to say, be careful with the SMD parts, it is all pretty small and fragile. Warning: Do NOT test this naked board
on 12 Volt to check voltages or something....As long as the clock signals are NOT connected to some kind of low impedance
output (like the Mainboard) the PCM1794 chip might start oscillating and actually blow up!
I had this a few times, before I found out what the issue was. So take my free advise and save money ;-)
Also here, a small help to visually check how the end result has too look like
Stacking the Decks
Not much to say, just a visual help how it is done. Nice and stable mechanical solution I must say :-) May be a small tip. The 10mm
hex-spacers from the Mainboard can be used for the first deck as well. Only for the other decks you must take 15 mm.
(when using more than one Deck)
(to avoid damage):
as the capacitors are 13 mm high, there is only 2mm space between the solder joints of the capacitors of the deck above.
YOU HAVE TO CUT THESE JOINTS VERY SHORT in order to avoid a shortcut between 12 Volt and GND.
A good TIP I received: when mounting the next deck, put a postcard or similar between the decks. if you can remove it easily afterwards
there is no short between the joints and the underlaying capacitors :-)
|Parallel Mode zoomed in:|
A clear view how the decks stack mechanically
Wiring the Decks
Use the supplied silver wire to connect the decks to the Mainboard. Just feed it through the holes from top to bottom.
(Or the other way round, if you prefer ;-)
I cannot repeat enough, solder the wires very thoroughly and triple control
if you had them all. If one clock stays open, you will blow up the 1794 chip...
|Wiring the Decks:|
From experience I like to warn, to double, triple check if ALL solder joints are made
My personal DAC - view 1
What you see here is the bottom plate of the Schaeffer Chassis I have had produced for my personal DDDAC1794.
All my equipment is now having a similar look and feel and on top, it saves a lot of ugly hole drilling etc.
Everything was pre drilled, so assembly is pretty easy. The holes fit perfectly with the place where the screws
go into the spacers :-) From here I just offer 4 perspectives of the inside of my DAC chassis.
|DDDAC chassis 1:|
Good view how the DAC part and power supply have their respective sides of the chassis
My personal DAC - view 2
Suddenly a few more things show up. Actually this is my personal choice and must not be followed. The metal blocks are the MU-Metal enclosures
from the Sowter output transformers. Even though you can't see the Mundorf capacitors, the relays behind the transformers are there
to be able to switch between output options. Bit crazy under normal conditions, but do not forget, I wanted to experiment and conduct
listening tests to select best options for power supply and output decoupling.
Therefore a selectable output is a good idea.
|DDDAC chassis 2:|
In the middle are the selectable output options (Transformer and Capacitor)
My personal DAC - view 3
A prominent view on the power supplies. The top one is a 5 Volt version for the WaveIO Board (max 1A). The one at the bottom,
a somewhat oversized 12 Volt version with double output delivering max 2A.
You do not need this, as the WaveIO can be fed from the PC's USB power supply as well.
The 12 Volt can be a battery or any other 12 Volt supply. Nevertheless, these sound awesome :-)
So I had PCB prototypes produced.
Actually the top one is very suited to be offered as a kit, so I will work that out and offer that in the web shop. The same PCB can be used to
make a 5 Volt or 12 Volt supply. Only the transformer needs to be different voltage (Size stays the same).
|DDDAC chassis 3:|
Good view on how the WaveIO is positioned and connected
My personal DAC - view 4
Little more to say.... of course the whole thing needs to be wired up, but there is nothing to say...
...other than, do not swap plus and minus.
This will be a very early end of your DAC ;-)
|DDDAC chassis 4:|
Last view of four 360 degrees images...
The power supply prototype
There is a separate section on this, so please refer to this on the why and what of it. Again, the top one I will make available
as kit for 5 Volt and 12 Volt. It will deliver up to 1A what is sufficient for the WaveIO Module and the 4 Decks
(even more, but I did not test more than 4 decks yet ...)
|DDDAC power supply:|
These are prototypes. I will work out the final PCB lay-out and make a kit available
You can easily recognize the fact; i use different sorts of wire. One size does not fit all :-) The signal wires are pure
silver wires in a Teflon tube. The power signals are copper 4sq mm. The thin wires are just to hook up the LEDs. At the right you see
a switch which allows to select USB Power for the WaveIO, or the 5 Volt DDDAC design power supply...
|DDDAC1794 completely wired:|
If you click the large image, you can see more details
I have made some drawings of the boards and their dimensions when stacked
(push the button below to download pdf file:)
Keep reading ...... the story continuous with the listening tests ( Sound Check )