Doodlebug - USB Isolator
May 14, 2015 at 12:38 AM Post #271 of 305
 
Is the ferrite core important in this application since the DoodleBug performs complete isolation?

FWIW, the ferrite is to protect components connected to the cable, since the cable acts as an antenna and pics up RF.
  If that's 12V DC, then yes.  If 12V AC, then it may be too much.

Thanks for the info.
 
May 14, 2015 at 11:07 PM Post #272 of 305
 
 
Is the ferrite core important in this application since the DoodleBug performs complete isolation?

FWIW, the ferrite is to protect components connected to the cable, since the cable acts as an antenna and pics up RF.

 
Yes.  Hence my rhetorical question: is a ferrite really important in this application?  To be more specific, the DoodleBug breaks the connection in the cable, so anything - including RF - is rejected at that point.  If a small enough cable is then used to connect the DoodleBug to the DAC, then what's the point?  Further, the USB cables we recommend all have shields.  Those should ground any extraneous interference signal.
 
Even then, the USB stream in the cable is digital, not analog.  Unless the RF is so overpowering as to interfere with the digital signal, I'm still wondering whether a ferrite will have any effect in this scenario.
 
The only other cables involved in the audio stream would be the RCA cables or headphone cable - not sure I've ever seen a ferrite on those, either.
 
I think it's important where video is involved.  That's a signal that's directly affected by the frequencies a cable might pick up, but I'm not so sure about the rest of it.
 
Jun 9, 2015 at 11:49 PM Post #273 of 305
Just built my Doodlebug. I second caution on the thermally capacious ground planes on this board. I am fortunate enough at work to have two soldering stations, so for the small stuff I used a small tip and low heat, and for the stuff on the ground plane I used a big spade tip to get plenty of heat to the board. After using the big guns on the ground plane this build went smoothly. (Except for those times where I put things in the wrong place...). I wish I used a hot air reflow station though, it really would have been a breeze.
 
This is my first kit build, though I've designed and populated my own surface mount PCB before. I would rather have this kit than trying to spin something myself, that's for sure! No worries about the parts, and everything is nicely organized into bags for really easy assembly. I only peaked at the instructions once to make sure I put the trim pot on the right way, in case the pinout wasn't what I expected.
 
Jul 2, 2015 at 3:57 PM Post #274 of 305
Quick question:
 
I relocated my office and had to unplug everything - for some reason the doodlebug is no longer recognized. I vaguely recall Fishki talking about a plug in sequence and recall having to go through a sequence back when I initially installed it but have tried every which set up and it doesn't seem to be recognizing. 
 
the question - is there a sequence that generally works ?
 
thanks ..dB
 
 
was loving it for all this time , thanks TomB
 
Jul 2, 2015 at 10:24 PM Post #275 of 305
  Quick question:
 
I relocated my office and had to unplug everything - for some reason the doodlebug is no longer recognized. I vaguely recall Fishki talking about a plug in sequence and recall having to go through a sequence back when I initially installed it but have tried every which set up and it doesn't seem to be recognizing. 
 
the question - is there a sequence that generally works ?
 
thanks ..dB
 
 
was loving it for all this time , thanks TomB

 
I have noticed a bit of sensitivity with the DoodleBug's connection.  It may have something to do with the ADuM isolation chip having to sync with the USB stream.  This occurs when I turn on or turn off another device on the same wall-power strip.
 
In any event, all I ever have to do is disconnect and reconnect the power supply to the DoodleBug - specifically, the 2.1mm connector to the DoodleBug.  I leave everything else connected when I do this and it always re-connects.  Hopefully, that will work for you.
 
Jul 2, 2015 at 11:46 PM Post #277 of 305
If your end device (DAC?) is plugged into another USB port the system will need to redetect/install the device.  Try plugging the device in first and get it up and running, then add the Doodlebug back in the chain.
 
Jul 4, 2015 at 7:09 PM Post #278 of 305
I finally had a chance to build the Doodlebug yesterday evening and it is currently doing its first few hours of service in my system with the PupDAC.

First impressions are that the background noise is completely gone (the laptop I use for audio is rather noisy at the best of times) and the bass response seems to be much tighter.

This thing is an absolute winner.

Be careful soldering the mini usb connector, it's probably the hardest part of the assembly.

I'll report back with some more impressions soon!

Great job Tom!!
 
Jul 4, 2015 at 9:28 PM Post #279 of 305
I finally had a chance to build the Doodlebug yesterday evening and it is currently doing its first few hours of service in my system with the PupDAC.

First impressions are that the background noise is completely gone (the laptop I use for audio is rather noisy at the best of times) and the bass response seems to be much tighter.

This thing is an absolute winner.

Be careful soldering the mini usb connector, it's probably the hardest part of the assembly.

I'll report back with some more impressions soon!

Great job Tom!!

 
Many thanks!  Glad you're enjoying it!
 
Yes, I agree that the USB connector is the hardest part in assembly.  I mentioned it to Avro during the prototyping, but a through-hole version would've screwed up the traces and the excellent grounding scheme/layout.  So, we went with it. 
wink.gif

 
Jul 8, 2015 at 11:42 PM Post #280 of 305
Well after a few more days of listening I can't stress the importance of partnering your PupDAC with the Doodlebug. No more pops & clicks or background hiss & the soundstage is really sharpened. Never been a huge believer in the virtues of clean power but this has converted me!

Another great way to use the doodlebug is with devices that need 5v DC. I have a handy little cable like this:
http://www.amazon.com/Generic-Volt-Barrel-Power-Cable/dp/B00304DZ7I

It plugs straight into a nos TDA1387 DAC I have which requires 5v and I've noticed similar sonic improvement.
 
Jul 9, 2015 at 2:21 PM Post #281 of 305
Well after a few more days of listening I can't stress the importance of partnering your PupDAC with the Doodlebug. No more pops & clicks or background hiss & the soundstage is really sharpened. Never been a huge believer in the virtues of clean power but this has converted me!

Another great way to use the doodlebug is with devices that need 5v DC. I have a handy little cable like this:
http://www.amazon.com/Generic-Volt-Barrel-Power-Cable/dp/B00304DZ7I

It plugs straight into a nos TDA1387 DAC I have which requires 5v and I've noticed similar sonic improvement.

 
Cool!  Thanks for the great comments on your experience with the DoodleBug!
 
Aug 7, 2015 at 7:14 AM Post #283 of 305
When do you think this will be available to buy?

You're kidding, right?
 
You might try looking at my avatar and googling "beezar" for a start. 
wink.gif
 
 
 
EDIT: That's assuming you're not a troll trying to build your post count and in order to post something in the For Sale section.
 
Nov 21, 2015 at 5:00 PM Post #285 of 305
Hey Everyone,
 
I just finished building my Doodlebug, and am currently enjoying a well-deserved listen to my "reference album" (and a beer :) ). The build itself I found to be quite easy, especially using the build-by-photo instructions on the diyfroums.org-site. I used a 25W soldering-iron, which, for some parts was not quite sufficient for parts connecting to the ground-plane, due to heat-drainage. At some point, I will give the whole thing a once-over with a bit more heat. 
 
I have a question that may have already be answered, but I couldn't find the answer to, namely: to what voltage should I set the Doodlebug when I have it connected to the pupDAC? For now, I've set it to 5.25V (using a 9VAC 500mA wallwart). 
 
I hope anyone can help out!
 
KR,
 
Gijs
 

Users who are viewing this thread

Back
Top