[tomb]

 

I think there's a huge potential here that may not have been previously mentioned. This should enable powering the pupDAC using USB on the go, from a mobile device, right, without completely draining the phone immediately, and without the likely crappy power coming off the phone(/wallwart that some OTG adapters can handle)?

Yes, indeed. You just have to observe the minimum input voltage requirements.
It would run quite nicely off 12 volt vehicle power. For DC, anywhere between
9 vdc and 12vdc would work great. Just don't exceed the working voltage of the
input cap which is 16vdc in the BOM.

 Hmm ... maybe I should start stocking some car adapters!?

 

[Avro_Arrow]

Anyone wishing to use an alternate power source, this is an example of the mating power connector used in the Doodlebug.
Another example.
 
Cigarette lighter plug.

 

[DingoSmuggler]

I've completed one of my doodlebugs, and started on the 2nd. 

 
Found that soldering directly to the ground plane for the SOIC-16 chip wasn't as much fun as it sounds. For the 4 pins that were connected to ground, i found them a lot easier if you pre-heat the ground plane first. Use the ground pad on a nearby 1206 component such as C3 or C8, pump a lot of heat into the ground plane with your soldering iron, then move back to complete the join.

 

[tomb]

  I've completed one of my doodlebugs, and started on the 2nd. 

 
Found that soldering directly to the ground plane for the SOIC-16 chip wasn't as much fun as it sounds. For the 4 pins that were connected to ground, i found them a lot easier if you pre-heat the ground plane first. Use the ground pad on a nearby 1206 component such as C3 or C8, pump a lot of heat into the ground plane with your soldering iron, then move back to complete the join.

I didn't pre-heat the ground plane on mine, but it sounds like a great idea.  The ground planes on the DoodleBug are significant.

 

[preproman]

Not sure if this question have been asked before but - here it goes..
 
Would this work with USB converters i.e...  The Berkeley Alpha USB.  http://www.berkeleyaudiodesign.com/alpha-usb/  
 
If so the USB input on the Alpha is a USB 2 connector.  Would I have to get a special made interconnect  USB cable?

 

[Avro_Arrow]

The Berkley Alpha USB is a high speed device.
The Doodlebug does not work at high speed.
There are currently no high speed USB isolators.
The Doodlebug works only at USB Full speed.

 

[tomb]

Anyone else built one, yet?

 

[UKToecutter]

 
Not yet......
 
But, in my defence.  It is the Christmas holidays.
 
I have however managed to catalogue all my recently acquired components onto my stock database AND tidied my workbench.

 

[lordearl]

I need to get a temperature controlled soldering iron to make mine......the SMD parts look to be a little tricky for my trusty old cheapie iron!!

 

[snaky]

There are currently no high speed USB isolators.

That's quite a sad situation. M2Tech HiFace Two and all DACs, which exclusively work in 480Mbit USB High speed connection - and they are many - need high speed USB isolator.

 

[Avro_Arrow]

You can still do some things...
You can run the signal through a hub chip to try and clean it up...
You can feed that hub chip with a fancy clock for hopefully less jitter...
Use a better power supply...
...but you just can't break the ground. No isolation.

 

[snaky]

  You can still do some things...
You can run the signal through a hub chip to try and clean it up...

Does it really work? Did anybody try to use a modern USB3.0 hub with DIY good linear PSU as an isolator or at least cleaner?
 

Use a better power supply... 

Some people are crazy enough to build a linear PSU for Mac Mini i7

 

 
It wouldn't be that crazy for RaspberryPi though.
 

 ...but you just can't break the ground. No isolation.

Well, I think with a declining state of SPDIF and rising of I2S as a new common interface for computer audio (that is 99% of audio these days actually) the problem would be much better served by properly designed USB-I2S interface, where isolation is done.
Like XMOS based solutions (preferrably clocking from DAC that is not the way XMOS datasheet examples do 

but it can be done using the MCLK for the clock source for the BCLK and LRCLK)
 
Talking about crazy (but available off-the-shelf) solutions - two USB-Ethernet bridges with fiber interfaces and cables for ethernet should do the isolation for USB2.0 High speed

 

[Beefy]

Long time no see for most of you folks!

 
My soldering iron has been getting rusty, my DIY fingers itchy, so this looks like a great little project to add to a couple of my USB DACS. Just thinking that a really great idea to include with the kits would be a short USB cable to connect between the D/B and the DAC...... short cables like this are often difficult to get locally, and probably wouldn't justify a monoprice order for most people......

 

[tomb]

  Long time no see for most of you folks!

 
My soldering iron has been getting rusty, my DIY fingers itchy, so this looks like a great little project to add to a couple of my USB DACS. Just thinking that a really great idea to include with the kits would be a short USB cable to connect between the D/B and the DAC...... short cables like this are often difficult to get locally, and probably wouldn't justify a monoprice order for most people......

You nailed it, Beefy.  I've been looking for one, but haven't found any that are reasonably priced.  If someone could point me in a good direction, I'll start including them in the kits.
 
P.S. Monoprice was the first place I looked.  I can't find anything under 1.5 feet.  When I've found the shorter ones, they're expensive and no volume discount.

 

[DingoSmuggler]

jdslabs do an 8cm mini USB, if that's any help
 
Hey beefy, happy Australia day mate