Doodlebug - USB Isolator

[Jasper9395]

 
Is the USB to S/PDIF optical or co-ax?
If it is co-ax, then the Isolator will block noise by breaking the ground loop.
If it is optical, then there is no ground loop anyway.
The ADuM3160 does clean up the signal to some extent...it doesn't just
copy the signal ad-hoc from one side to the other.
Of course, whatever chip runs the USB to S/PDIF conversion (PCM270x maybe?)
could possibly benefit from the better power supply.
 
In the end though, I would make no guarantee of any audible improvement, as
this is not really the kind of device it was design for.

I use a musical fidelity v-link (which uses a TAS1020B chip?) and connect it to the DAC though optical out. Think it will be interesting to see how much of a difference the Doodlebug can make.

 

[Avro_Arrow]

 
Which model V-Link is it?

The V-Link II would be compatible with Doodlebug, but
the V-Link 192 would not be.
 
I would be an interesting experiment.

 

[Jasper9395]

It's the V-link II. Could you explain the difference between the II and 192? I thought it was mainly the sample rate they work at. Think I'm going to give it a try when you guys make the kit available

.

 

[Avro_Arrow]

 
The difference is, the V-Link II works at USB Full Speed and the V-Link 192 requires USB High Speed.

The Doodlebug is a USB Full Speed device. You could still use a V-Link 192, it would just be limited
to 24 bit @ 96 k resolution.
 
More info on USB in general can be found here.

 

[Jasper9395]

I see, that makes sense. Thanks for the help!

 

[fishski13]

the Schiit guys told me the Gungnir operates at high speed 480mbsp vs 12mbps.  they also played around with the ADuM chip at one point.  the Doodlebug works with JRMC 18 and no upsampling into the Gungnir, but input dropped after 45min or so with no music playing.  i will play around with it a bit more tonight to see if i can get it less buggy (groan), but sonically, it's a mixed bag.  better instrument separation and blacker background, but musically sounds constipated. 
 
i'm sending the ODAC back to its owner along with the DB for his listening pleasure.

 

[Spiral Out]

Forgive me if this has already been mentioned in this thread but will the Doodlebug be available pre built or in kit form only? I have no experience with populating a PCB board and I'm very interested in using the Doodlebug with my ODAC.

 

[tomb]

  Forgive me if this has already been mentioned in this thread but will the Doodlebug be available pre built or in kit form only? I have no experience with populating a PCB board and I'm very interested in using the Doodlebug with my ODAC.

That's certainly the plan.  My ability* to build is limited, so the numbers may be small and stock variable, but my intent is to offer pre-built as well as kits.
 
 
* translated means "time"

 

[Spiral Out]

 
That's certainly the plan.  My ability* to build is limited, so the numbers may be small and stock variable, but my intent is to offer pre-built as well as kits.
 
 
* translated means "time"

That's great news! I am most definitely interested in purchasing one. Any idea on pricing at the moment?

 

[fordgtlover]

Reporting back in on the prototype build...
 
I had an issue with the part originally suggested for J1, but I believe that's been reported and addressed
 
LED direction markings are likely to confuse people.
 
All standard parts except for lower spec capacitors for C5 & C6 rather than the Panasonic FMs.
http://au.mouser.com/Search/ProductDetail.aspx?R=515D477M016CC6AE3virtualkey61320000virtualkey75-515D477M016CC6AE3
 
Otherwise, the only feedback on the build is the amount of heat required to solder many of the parts with the size of the ground plane.
 
 
I'm using a 9VAC wallwart. Board voltage was very close to 5V at first test, small adjustment and now perfect.
 
I'm listening to my ODAC now with the Doodlebug and sounds great.I'll report back in after trying it with a few of my other USB devices.
 
Thanks to TOMB and Avro_Arrow.

 

[Ableza]

Watching with interest.  Once the Doodlebug is ready for prime time, I assume it will be available on Beezar.com?

 

[dBel84]

Thought I should feedback on the sound too - build went without a hitch per pics I posted earlier. Only issue I had was that the PC would not recognize the unit but after fishki slapped me about the head a few times I realized how silly the problem was. The doodlebug has to be connected to the dac first and then plugged into the pc  - has been working without a problem for at least a week in my office. I think the edginess of the odac is more tolerable now with headphones. In my office I listen mostly nearfield and it has never been a problem but I feel that there is an overall improvement which has been evident as I listened over the past week. 
 
I will re iterate thanks to TomB and AA

 

[skeptic]

subscribed!

 

[JacobLee89]

Just wondering if anyone has anything to say about their current doodlebugs, or what designs changes/fun things they have used doodlebugs for. This project seemed to have quietened down a bit.

 

[mcandmar]

I got a doodlebug pcb last week, just waiting for the bits to arrive from Mouser to start testing.  I believe i got one of the first production boards so i expect they will be available on the website any day now..