Looks like parts come in less than $150.
(uh, embedded table messed up the layout of this site. I'll attach instead.)
(uh, embedded table messed up the layout of this site. I'll attach instead.)
Is there a complete layout availible jet? if i know where to find those regulators i might be able to build one in the weekend..
/micke
/micke
hifi said:
I haven't been getting an outpouring of design confirmation here. Has anyone really looked at the circuit? Someone needs to review the design to make sure that the CS8420 and CS43122 are configured for correct operation, and that the pull-up/down resistors are of an acceptable value.
Changes in this revision:
<ul>
<li>Added a 75Ω BNC input with transformer coupling.
<li>Added one more ferrite bead
<li>Reduce board size to 9in<sup>2</sup>
<li>Correct input on 43122 mute pin
</ul>
<a href="http://atari.saturn5.com/~jwb/43122/schematic.png">Schematic</a>
<a href="http://atari.saturn5.com/~jwb/43122/manuf.zip">Gerber and Drill files</a>
<img src="http://atari.saturn5.com/~jwb/43122/ss-cont.png">
<ul>
<li>Added a 75Ω BNC input with transformer coupling.
<li>Added one more ferrite bead
<li>Reduce board size to 9in<sup>2</sup>
<li>Correct input on 43122 mute pin
</ul>
<a href="http://atari.saturn5.com/~jwb/43122/schematic.png">Schematic</a>
<a href="http://atari.saturn5.com/~jwb/43122/manuf.zip">Gerber and Drill files</a>
<img src="http://atari.saturn5.com/~jwb/43122/ss-cont.png">
Here's one for you split ground plane fans:
<img src="http://atari.saturn5.com/~jwb/43122/ss-split.png">
<img src="http://atari.saturn5.com/~jwb/43122/ss-split.png">
In reply to a question I recieved by email:
The power supplies are left to the discretion of the builder. In the single groundplane version, there is one entry point for +10V/0V/-10V. This is flexible, and you could easily use +/-12V or +/-9V instead. In the split groundplane version, there is a top entry point for +10V/0V/-10V, and two entry points in the digital section for +10V/0V. For the digital supplies (lower half of the board) you could use anything from +7V to +20V.
The power supplies are left to the discretion of the builder. In the single groundplane version, there is one entry point for +10V/0V/-10V. This is flexible, and you could easily use +/-12V or +/-9V instead. In the split groundplane version, there is a top entry point for +10V/0V/-10V, and two entry points in the digital section for +10V/0V. For the digital supplies (lower half of the board) you could use anything from +7V to +20V.
Updated bill of materials is here:
http://atari.saturn5.com/~jwb/43122/bom.html
The cost to build two of these boards would be about $280 for parts and $80 for boards. Without shipping costs that is only $180 each.
I think I will go ahead and build a couple of these suckers. Does anyone want a board to play with? The prices are much better in quantity
Edit: The parts price comes down by $28 if I substitute ZTX450 for ZTX869. The 869 is <em>way</em> overkill and costs a lot.
http://atari.saturn5.com/~jwb/43122/bom.html
The cost to build two of these boards would be about $280 for parts and $80 for boards. Without shipping costs that is only $180 each.
I think I will go ahead and build a couple of these suckers. Does anyone want a board to play with? The prices are much better in quantity
Edit: The parts price comes down by $28 if I substitute ZTX450 for ZTX869. The 869 is <em>way</em> overkill and costs a lot.
hifi said:
There is already a supervisor to handle the reset pulse. It is the unlabelled three-terminal device in the center of the schematic. Sorry my drawings are so poor
Well, I have decided to build a prototype for this DAC, but I can't find CS43122 at retail anywhere. Newark carries them, but they are out of stock for 21 days. Does anyone else carry them, or shall I just wait? The cs4396 is pin compatible but I don't think it will sound as good.
As it turns out, Newark has shipped my order despite their claim that it was 21 days backordered.
I ordered boards from PCB Express. They are two-sided with plated through holes and no solder mask. The power supplies are built and tested. I suspect I will have a working prototype in mid-November, assuming the design is correct.
I'm still worried that 4.7kΩ pull-up resistors may have been the wrong choice.
I'm still worried that 4.7kΩ pull-up resistors may have been the wrong choice.
that sounds a litte low...i think 10-47k is mor like it.. but then again it will be rater easy to change them.
/micke
/micke
hifi said:
But at 47KΩ, if the pin sinks 6µA, the voltage will already be above the low threshold. This is the problem with trying to pull down.
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