# Doodlebug - USB Isolator



## tomb

For awhile now, I became aware in an acute sense of how fickle a USB connection and power supply is from many PC's, especially a laptop - even one with an elaborate docking station, etc. The reason is that the pupDAC, designed by cobaltmute, seems to push the limit of what is possible with a USB-powered DAC. Every voltage source needed on the pupDAC is regulated. However, the power consumption and voltage needed to maintain the regulation and data streams may significantly tax a computer's USB power supply.
  
 At work, we've all converted to laptops with docking stations (part of the "teleworking" movement). I regularly have my pupDAC knock off line at work, have to re-start Foobar2000, and unplug and re-plug the DAC numerous times, all depending on what I'm doing at the time I'm listening to music. Besides that, the exquisite detail is lost compared to when I listen to it at home with my ample-power-supplied tower PC. For awhile, I thought perhaps that a powered-USB-hub was an answer. For instance, there are numerous reports of the ODAC performing better with a powered-USB hub compared to a basic USB connection. It didn't seem to work in my case. The sound was still bad on my docking station at work and it didn't prevent it from knocking offline.
  
 Enter *Avro_Arrow* with a design called the Doodlebug - a USB Isolator.* Avro's design is based on some new chips that Analog Devices have developed for isolating a streaming, USB connection.  The Doodlebug is based on the ADuM3160.  Besides isolating the USB data streams, it also isolates the downstream power connection from the upstream USB bus.
  
 Accordingly, the Doodlebug also includes an externally-powered, linear-regulated power supply. Further, since the voltage is small with USB, Avro uses several diodes to provide the voltage drop control and reference for the LM317 power supply. The result is a stable, high-quality _and_ low-noise power supply that IMHO, improves the sound quality and reliability of any USB-powered DAC. Even with my [formerly] OK desktop tower at home, the Doodlebug has noticeably improved the sound quality of the pupDAC. More micro-detail is heard, firmer bass, and none of the knock-off-line irritations.  Tests at work have yielded similar results: sound quality is equal to at home and there are no more line knock-offs.
  
 Best of all, it's a fairly simple build and inexpensive, to boot. Here is a pic of the first prototype:
  

  
 The terminal blocks, heat sink, and switch were pre-pre-prototype configurations for simplicity of testing.  The next set of prototype PCB's (currently in shipment) use USB connectors on both ends and with the selected walwart, no giant heat sink is needed for the LM317.  The switch was also deleted and a trimmer included to account for the variances in USB bus voltages of a source PC.
  
 I think it's an easy statement to make that the Doodlebug will improve the sound quality and reliability of any USB-powered DAC.
  
 EDIT: Full details on the production prototype here:
*Doodlebug Production Prototype website*
  
  
  
 * Full disclosure, there is a somewhat similar device available on HiFiDIYme called the "USB Isolator," but it does not use a full-blown, linear-regulated power supply.


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## tomb

We are asking for a few volunteers to prototype the current version of the Doodlebug.  The new layout is here:

  
 We (Avro_Arrow and myself) need 5-6 volunteers who will agree to build one fairly quickly, test it out on their USB DAC, and report back in this thread with feedback.  I would really love to get someone who has an ODAC or other non-Beezar DACs to try this, too.  It should improve the performance of almost any USB DAC.
  
*PCB's will be free.*  I'll supply a web page in a couple of days that will have the Bill Of Materials, schematic, etc.  Please PM me if you are interested.
  
 P.S. Avro_Arrow sized the PCB for the Hammond 1455C801 case. 
	

	
	
		
		

		
			





 
  
_NOTE:  The Analog Devices chip is compatible with USB 2.0 and below._


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## 00940

Great news. More choice is good


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## dBel84

This is cool Tom , I would be up to build one of these  -  I actually recently revisited the usb isolator designed by oleg as I thought it would be interesting to see how this impacts the odac I have at work. 
  
 ..dB


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## tomb

dbel84 said:


> This is cool Tom , I would be up to build one of these  -  I actually recently revisited the usb isolator designed by oleg as I thought it would be interesting to see how this impacts the odac I have at work.
> 
> ..dB


 

 Thanks!
  
 PM me with your address - the PCB's are going fast!


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## tomb

5 PCB's are accounted for - 1 left.
  
 EDIT: Still need a couple of addresses from the volunteers thus far.


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## fishski13

i'm in if still available.


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## tomb

fishski13 said:


> i'm in if still available.


 

 Got you - you're the last one!
  
 All PCB's are accounted for ...  I will post and include pics when they arrive.  I thought maybe they'd be here today, but nope ... maybe Monday.


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## fishski13

Awesome!


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## Cheerwino

tomb said:


> We (Avro_Arrow and myself) need 5-6 volunteers who will agree to build one fairly quickly, test it out on their USB DAC, and report back in this thread with feedback.  I would really love to get someone who has an ODAC or other non-Beezar DACs to try this, too.  It should improve the performance of almost any USB DAC.


 
 Tomb, I got no skills to build one but I do have an ODAC and would love to try it out, if you are looking for more guinea pigs. I have been looking for a USB isolator and was rather confused by the options (or lack of). BTW, I'm just up I-85 from you in Greenville, SC. PM me if I can be of assistance. All the best to you in this most worthy project!


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## TheShaman

Nice one, count me in for a PCB.


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## tomb

PCB's are in!  Not enough time tonight, but I'll try posting some pics tomorrow.  Sorry, but I'm still working on the webpage for the BOM, etc.  It's just kind of tough for me Mon-Thurs, but I'll keep trying to get it posted.  Stay tuned ...


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## Avro_Arrow

Great news Tom!

  
 I guess I will have to order my parts as soon as the credit card billing cycle
 rolls over...
  
 If you stick with the 6 volt wall wort for the other prototypes, I do the 9 volt
 one for mine.


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## JacobLee89

I also own an ODAC, though it seems I may need to wait for a bit until the next batch is ready.
  
 I'm definitely interested to join the next group of "testers", if not for testing then sign me up as an interested patron!


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## tomb

Yes - sorry to say all the PCB's are spoken for.  I hope to get them shipped out on Friday.  Mon-Thur is very busy for me, this week more than usual.  Beezar will be moving, as a matter of fact, in about a month and a half.  So things are very hectic around here, right now. 
	

	
	
		
		

		
		
	


	



  
 Anyway, here are some pics of the PCBs!



 They're attached together in threes.  I should be able to break them apart without much trouble.  It's certainly not like the share sides with a scoring mark - those are very tough to separate.


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## Avro_Arrow

The boards look good.

  
 I should be able to get one together next Friday
 or when I get a board...whichever comes later.


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## music_man

okay, I see why you did not like my little discovery. I am just guessing yours is better 
	

	
	
		
		

		
			





 could you say what wallwart you are using  please. or if it is custom post a pic? thanks. I was just interested in what it looked like.


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## DingoSmuggler

I'm very interested in grabbing a few of these when the production boards/kits/whatever are released.
  
 Any reason not to use smd rectifiers also? Should make a quicker and cleaner build.


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## Avro_Arrow

dingosmuggler said:


> Any reason not to use smd rectifiers also? Should make a quicker and cleaner build.


 
  
 I can easily change to SMD rectifiers.
 I had no compelling reason to use one over
 the other and 1N400x are cheap and plentiful.


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## Avro_Arrow

music_man said:


> could you say what wallwart you are using  please


 
 The isolator is designed to use pretty much any AC or DC adapter
 working at 6 VAC up to 9 VAC @ 1 A. It has a bridge rectifier and
 regulator on board.
Here is an example


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## tomb

avro_arrow said:


> dingosmuggler said:
> 
> 
> > Any reason not to use smd rectifiers also? Should make a quicker and cleaner build.
> ...


 

 Yes, I have no issue with the rectifiers either way.  When we get to kitting it, I will probably use the same rectifiers that I have for MiniMAX kits and other designs.  It's sort of like the PupDAC in that there will probably always be a mix of SMD and through-hole, because of the capacitors and LEDs, I think.  The through-hole diodes are awfully cheap and plentiful everywhere, though.  Avro's response also indicates the flexibility - 1N400*X.  *So, pretty much any voltage rating will work.
  
 I hope to have the web page and BOM up sometime tomorrow - been working on it!


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## tomb

*Doodlebug Prototype website*


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## Avro_Arrow

Looks good

 I like the "Doodlebug" logo.
 Now we just need a cute bug graphic...
  
 After I hear back from the prototypers,
 I'll have a version 2.5 for production (I already
 made a sight change based on what saw
 on the 2.4 board).
  
 Good luck to the prototype builders!


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## tomb

Thanks, Avro!
  
 Another day delay in shipping - I spent all day getting the BOM and the webpage setup that I don't have time to go to the Post Office.  I do have the envelopes prepared, though.  They'll go out tomorrow.


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## tomb

fordgtlover pointed out that the C1 cap is out of stock at Mouser already.
	

	
	
		
		

		
		
	


	



  
 I'm ordering this one tonight:
 75-MKT1817210404
 It's a Vishay-Roederstein, which I've always considered equal to Wima's and it's almost the very same size.  This is for power decoupling at the USB input jack, too - so no great need for super-high-quality, I would think.


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## Avro_Arrow

Yea, as long as it's an appropriate value and voltage and fits the footprint...
There are only a couple components on the whole boards that are in
any way critical.


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## dBel84

parts ordered


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## RagunaAsh

avro_arrow said:


> The isolator is designed to use pretty much any AC or DC adapter
> working at 6 VAC up to 9 VAC @ 1 A. It has a bridge rectifier and
> regulator on board.
> Here is an example


 

 Sorry, just to clarify, the power can also be 6-9 VDC? Or is it limited to 6-9 VAC?


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## dBel84

it has to be AC as there is onboard rectification


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## smial1966

Eventually, will the Doodlebug be available built to purchase? As there are those of us that really are technically inept.


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## RagunaAsh

Here's a cheap wall wart on Amazon, if anyone's looking!
  
 http://www.amazon.com/AC-AC-ADAPTER-9VOLTS-1000mA-2-1mm/dp/B00ATECBMM/ref=pd_cp_e_0


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## muskyhuntr

Parts ordered.


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## JacobLee89

Just a quick question, and hopefully I won't come off as too annoying/keen.
  
 When do you plan on releasing/selling the next batch of PCB's? I am assuming that this first batch is for troubleshooting and/or further development of doodlebugs design, and the second batch would most likely be released after these changes have been made.


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## DingoSmuggler

avro_arrow said:


> Now we just need a cute bug graphic...


 
 I had an idea of using the usb logo for the legs.
  
 The following is not an attempt for the actual logo, simply demonstrating the idea.
 (_i'm not a graphic designer, and not about to start_)
  

  
 If going for a real cute bug (nothing like the above) i think it would still be cool if its front feet were circular, middle one's triangular, and rear feet square, as a reference to USB.


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## JacobLee89

dingosmuggler said:


> I had an idea of using the usb logo for the legs.
> 
> The following is not an attempt for the actual logo, simply demonstrating the idea.
> (_i'm not a graphic designer, and not about to start_)
> ...


 
  
 If you ask me, that's already demonstrating the idea very well, and has definitely got me thinking. Let me ponder with some sketches and see if I can build upon your idea.
  
 *quick edit*
 Here's a few rough sketches. Since I'll be busy for most of the day until about GMT 23:00 ish, I guess the next best thing is to throw these in to generate discussion and ideation.


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## tomb

jacoblee89 said:


> Just a quick question, and hopefully I won't come off as too annoying/keen.
> 
> When do you plan on releasing/selling the next batch of PCB's? I am assuming that this first batch is for troubleshooting and/or further development of doodlebugs design, and the second batch would most likely be released after these changes have been made.


 

 Yes, but it all depends on the builders for this prototype.  They don't work for Avro or me and we can't enforce any kind of schedule. 
	

	
	
		
		

		
		
	


	




 
  
 You'll just have to stay tuned ... it's the way DIY works.


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## tomb

dingosmuggler said:


> avro_arrow said:
> 
> 
> > Now we just need a cute bug graphic...
> ...


 

 OK, now - don't you guys go posting something like this unless you mean it. 
	

	
	
		
		

		
		
	


	




 
  
 I like it ... a lot!  Can Beezar use this freely?


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## tomb

Everything's packed ... heading to the Post Office ...


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## DingoSmuggler

tomb said:


> OK, now - don't you guys go posting something like this unless you mean it.
> 
> 
> 
> ...


 
 Sure.


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## Avro_Arrow

ragunaash said:


> Sorry, just to clarify, the power can also be 6-9 VDC? Or is it limited to 6-9 VAC?



 


If you plan to use a DC adapter from the start, you can just install a couple jumpers in place of the rectifier diodes.
You can also use a DC adapter even with the bridge installed, you will just loose a couple diode drops in voltage but
the polarity if the connector wont matter.


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## Avro_Arrow

tomb said:


> OK, now - don't you guys go posting something like this unless you mean it.
> 
> 
> 
> ...



 


I like it too!


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## tomb

OK - all PCB's are now shipped!  I used 1st Class envelopes, so there's no tracking.  Please let me know if you have any issue.  Domestic should receive them by Tuesday, maybe Wednesday at the latest.  I'd allow 2 wks for International.
  
 The bad news is that I forgot something on the BOM and I apologize profusely: the walwart.
  
 The ideal walwart is at DigiKey: *T1124-P5-ND** .  *Mouser is a bit of an issue, because there are no AC walwarts in the voltage range we want.  DC is still OK, but you better go for 9V to account for the drop through the diodes, etc., unless you leave the ones out that are rectifying.  Avro_Arrow can probably elaborate on this when he gets a chance.  I'll have the BOM corrected and re-posted, but again - please accept my apology.
  
 EDIT: I just got back from the Post Office and started posting on the page that was already loaded when I left, so I didn't see some of Avro's posts:
  
 1. As far as we are concerned, DingoSmuggler's logo is it.  It's simply outstanding!
 2. Avro_Arrow is the expert, but the part about the DC vs AC walwart is that it's important that you allow enough voltage to provide 5.25VDC.  That's what we're shooting for.  Many, if not most, of the high-quality DACs we want to use have many regulators on board.  For instance, the pupDAC has some that provide +or- 4.75VDC for the voltage swing on the analog output.  It's important to have enough over-voltage that the DAC's regulators are not thrown out of their linear range.  Most are all low-dropout regulators, but the LM317 on the Doodlebug is not.  To maintain 5.25VDC, it will need 7.25VDC (DO voltage = 2V).  A 6VAC walwart will gain voltage through rectification, a DC walwart will not.
  
 In any event, this is one of the reasons for still prototyping.  I'll try to come up with a list sometime today of other suggested walwarts.  Avro_Arrow sent me several over the last month or two.  Jameco is perhaps a good source, too - they like to stock a lot of wall adapters.
  
 EDIT: Corrected the DCV recommendation to 9VDC, per Avro_Arrow's recommendation.


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## Avro_Arrow

I would say a 9 volt DC @ 500mA to 1 A would be a good substitute walwart if you want to go that route.
For AC, 6 volts @ 1 A or 9 volts @ 500 mA are recommended.


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## head-hi

I will be following this for a possible future purchase. I'm using this isolator/PS combo and find it provides a substantial improvement in sound to my setups:
  
http://www.ab-system.hk/index.php?route=product/product&path=73&product_id=63
http://www.ab-system.hk/index.php?route=product/product&path=73&product_id=64
 with the upgraded Cardas cable:
http://www.ab-system.hk/index.php?route=product/product&path=73&product_id=173
  
 This and the Stoner Acoustics DAC and a BH2 headphone amp make a killer low-cost kit.
  
 I wish you success and believe this is a great idea. I have a feeling we'll be seeing more of these types of products when people realize their effectiveness.


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## tomb

I've updated the BOM with an alternate for the C1 capacitor at Mouser.  Also, it now includes the walwart. 
	

	
	
		
		

		
		
	


	




  I've listed several alternatives besides the primary choice at DigiKey.


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## fordgtlover

dingosmuggler said:


> I had an idea of using the usb logo for the legs.
> 
> The following is not an attempt for the actual logo, simply demonstrating the idea.
> (_i'm not a graphic designer, and not about to start_)
> ...


 
 That would get my vote. I think it's great.
  
 Initially, I thought the USB _Trident _would surely be trademarked or copyrighted, but I can't find it listed in the USB IF documentation linked below.
  
 http://www.usb.org/developers/logo_license/USB-IF_TLA_Usage_Guidelines_082713.pdf


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## music_man

i saw a product called mophie. about the size of this. that might provide even better power and make this portable. i have no idea if it is worthwhile i just figured id mention it.


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## JacobLee89

music_man said:


> i saw a product called mophie. about the size of this. that might provide even better power and make this portable. i have no idea if it is worthwhile i just figured id mention it.


 
  
 I think it may help "some" usb dacs. I can't say how much it'll improve the output on, lets say, mobile phones if this was anyway possible but it's food for thought.
  
 May not help people like me since I'm a desktop sort of guy.


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## muskyhuntr

Hi All,
  
 Board received....and it really is purple!  Now waiting on Mouser and Digi-Key. 
  
 Jim


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## Avro_Arrow

We found our first error...

 The EAGLE footprint for J1 was not correct.
 The footprint was set up for pins and the part
 has tabs. I have modified the EAGLE footprint
 to reflect reality.
  
 My recommendation is to trim down the tab
 to fit the hole.


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## fishski13

got the board today.  thanks Arvo and Tomb!!!
  
 finalizing and placing Mouser and Digikey orders tonight.


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## Avro_Arrow

fishski13 said:


> got the board today.  thanks Arvo and Tomb!!!
> 
> finalizing and placing Mouser and Digikey orders tonight.


 
 Your welcome!
  
 Just placed my order too (all from Digi-key).
 I don't expect the board for a few more days.


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## dBel84

my wife thought it was junk mail but i spotted the doodlebug , saved in the nick of time


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## fishski13

looking at the datasheet, the SMT type version for J1 is a little wide for the board pads, but may work:  http://www.mouser.com/ProductDetail/Hirose-Electric/UX60-MB-5ST/?qs=%2fha2pyFadug63YtrwsEixoQPqVODSOA1lIiVOr57FQKNZt%2fo%252bCTYTA%3d%3d .


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## Avro_Arrow

fishski13 said:


> looking at the datasheet, the SMD version for J1 is a little wide for the board pads, but may work:  http://www.mouser.com/ProductDetail/Hirose-Electric/UX60-MB-5ST/?qs=%2fha2pyFadug63YtrwsEixoQPqVODSOA1lIiVOr57FQKNZt%2fo%252bCTYTA%3d%3d .


 

 I fixed the problem for the next run of boards already.
  
 I was going to use the smd version but was concerned about mounting security.
 I figured the mounting tabs would be more secure.
 The full through hole version I did not like, it did not route well.


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## fishski13

dbel84 said:


> my wife thought it was junk mail but i spotted the doodlebug , saved in the nick of time


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## fishski13

avro_arrow said:


> I fixed the problem for the next run of boards already.
> 
> I was going to use the smd version but was concerned about mounting security.
> I figured the mounting tabs would be more secure.
> The full through hole version I did not like, it did not route well.


 
  
 probably a good idea for those that want to use manly heavy/stiff audiophile USB cables 
	

	
	
		
		

		
		
	


	




.


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## RagunaAsh

Quick question: what's C8? I don't see it on the BOM...


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## RagunaAsh

Same question with R5?


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## fishski13

my MF V-Link USB-S/PDIF converter draws a max 160mA.  I'm wondering if the 200mA DC current rating of the ferrites is enough engineering margin of error?


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## RagunaAsh

Also, IC1 on the board is IC2 on the BOM, and vice versa.


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## DingoSmuggler

fishski13 said:


> my MF V-Link USB-S/PDIF converter draws a max 160mA.  I'm wondering if the 200mA DC current rating of the ferrites is enough engineering margin of error?


 
 Well it should support up to 500mA, so 200mA is going to be too small. It won't matter on the input side though.


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## Avro_Arrow

R5 is one of the four 24 ohm resistors.
 C8 is one of the four 0.1 uF bypass caps.
 The ferrites are supposed to be rated for 1500mA
  
 There is an auto-reset fuse @ 500mA on the 5 volt out.


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## Avro_Arrow

My apologies everyone....I should have double checked Tom's BOM.
  
 The ferrite on mouser should have been this one.
 The ferrite on digi-key should have been this one.


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## RagunaAsh

There are only three 24 ohm resistors and three 0.1uF capacitors listed on thr BOM. 





avro_arrow said:


> R5 is one of the four 24 ohm resistors.
> C8 is one of the four 0.1 uF bypass caps.
> The ferrites are supposed to be rated for 1500mA
> 
> There is an auto-reset fuse @ 500mA on the 5 volt out.


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## Avro_Arrow

Tom is offline currently due to weather but

 he want me to pass along that he will send
 everyone the missing cap and resistor.


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## tomb

avro_arrow said:


> Tom is offline currently due to weather but
> 
> he want me to pass along that he will send
> everyone the missing cap and resistor.


 
 Back up!
  
 Ferrites will be sent, too. Sorry about these mistakes. 
	

	
	
		
		

		
			





 
  
 As for the mini-USB jack, if you use some flush cutters and cut right across the holes in the mounting tabs, that should allow you to solder it down flush.  I was still able to solder it from the bottom and have the solder wick through up the sides of the jack's body.  It's fairly easy if you get the tabs cut just enough to let the jack be flush to the PCB.  Then the plastic locating pins will keep it straight while you solder from the bottom of the PCB.


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## tomb

smial1966 said:


> Eventually, will the Doodlebug be available built to purchase? As there are those of us that really are technically inept.


 

 Yes, that's the plan - along with kits, too, of course.


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## tomb

OK - sorry again for all these mistakes.
	

	
	
		
		

		
		
	


	



  
 1. The missing parts (C8, R5) and the correct ferrites (L1 - L4) have been ordered.  I will ship them out to each of you when I receive them, which should be no later than Monday, or Tuesday at the very latest.
 2. I've made the corrections to the BOM and uploaded all new files.  Please check it for me guys and see if everything is OK at this point.


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## Avro_Arrow

The Mouser BOM looks good.
  
 Digi-Key BOM:
  
 J2 should be PJ058AH
 L1-L4 should be this one
  
 I'm testing this 9 VAC adapter to add to the list.
  
 Here is an enhanced silk screen layer to help with parts placement.


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## Avro_Arrow

Opps...that J2 was out of stock.
  
  
 This PJ-058A instead...


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## Avro_Arrow

Just checked the mail...Got my board...Yah!

  
 My parts should be here in a couple hours too.
  
 Guess I know what I'm doing tomorrow...


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## tomb




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## smial1966

Excellent, thanks for letting me know. Good luck to all those intrepid DIY builders out there! 




tomb said:


> Yes, that's the plan - along with kits, too, of course.


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## tomb

OK - here's another goof up.  I guess it's good that I at least gave you the PCB's for free after all of this.
  
 Do not use the Right-Angle USB Type A jack given in the BOM - either from DigiKey or Mouser.  It's reversed.
  
 I will be sending the correct one in the mail with the cap, resistor, and ferrites.


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## fishski13

no worries.  this is prototyping and a gift to the DIY community.
  
 i just need the USB jack.  i ordered everything from Digikey this afternoon.


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## tomb

fishski13 said:


> no worries.  this is prototyping and a gift to the DIY community.
> 
> i just need the USB jack.  i ordered everything from Digikey this afternoon.


 

 Thanks.  The correct jacks were ordered before I made that last post.  Hopefully, they'll all arrive on the same day.  I knew the Molex said "reversed," but just didn't realize that translated to the pinouts, too.  The one specified is about $4-$5, depending on where you are when you order it.  I just knew there were some cheaper.  Sure enough, Avro_Arrow found some.  I'll update the BOM for several versions - but not until I confirm that they all work!
  
 BTW, the voltage/linear regulator part of the circuit works like a dream, at least with the spec'd 6VAC walwart from DigiKey.  I started out at 5.03VDC on mine and was able to very precisely adjust to 5.25VDC.  The trimmer works at about 0.02V per turn, giving you almost 1/2 volt of very precise adjustment.
  
 Also, I can speak from experience, now - the prototype PCB's are very robust and can withstand a lot of re-work.  I removed the Type A USB connector and was able to save both the connector and PCB without damage - no lifted pads or traces.


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## fordgtlover

Thank you kindly Tom.


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## muskyhuntr

Hi All,
  
 Got the power supply portion of the Doodlebug done.  No need for trouble shooting, came up first time!  Dialed in 5.000VDC and left it run for a half hour.  Stable.  Like Tomb, I was impressed with the precision of adjustment VR1 gives.  Only real problem I had was bending the diodes to the proper length (my problem not the boards).  SMD's were of the size that were easy to solder and placement of all parts was a piece of cake.
  
 I do have a few suggestions though.
 1) Make the pads for VR1 a bit larger.
 2) Make the pads for the LEDs a bit larger.
 3) ID polarity of LEDs on the board.
 4) Put 6VAC and 9VDC by voltage in connector.
 5) Would love to see a 5VDC output jack.  This device has uses beyond audio. For example robotics, micro controllers, protection circuit between computer and peripherals, etc.
 6) Possibly in final product, have a provision to mount one of the LEDs to the front panel as an ON indicator.
  
 Jim


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## Avro_Arrow

Time to take a break from house building and do some electronics...
  
 Improvised work area (the rest of my "shop" is all in boxes).
  

  
 For the SMD components, I used solder paste.
 For the through hole components regular solder was used.
  
 And...
  
 It Lives!
  


 Tested with the pupDAC and it works perfectly.
  
 I'll give it a more detailed test tomorrow. I'm powering it with a 9 volt @ 500mA
 adapter and the voltage at C5 is 13.5 volts with no load. I'll see what it is under
 load. I might want to change C5 to a 25 volt part to be safe.
  
 Before first power up, adjust VR1 all the way counter-clockwise.


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## tomb

avro_arrow said:


> Time to take a break from house building and do some electronics...
> 
> Improvised work area (the rest of my "shop" is all in boxes).
> 
> ...


 

 Sounds great!
  
 Yes, I'm familiar with working out of boxes right now.  I don't know what I've packed and what I haven't. Beezar is moving soon.
	

	
	
		
		

		
		
	


	



  
 Anyway, great work on the prototype!!


----------



## Avro_Arrow

tomb said:


> Anyway, great work on the prototype!!


 

 Thanks Tom.
  
 I had a chance to leave it running for a while and it barely got warm.
 No problem using the 9 volt adapter.
 Under load, the voltage at C5 dropped to less than 12 volts, so
 I guess the 16 volt cap will be fine with this adapter as well.
  
 I'm guessing most of the rest of you have the 6 volt @ 1 Amp adapter.
 When someone gets theirs up and running, can you let me know the
 no load and loaded voltage at C5?
  
 Thank you to all the prototypers for your patients with us.


----------



## fishski13

i will measure across C5, but i don't forsee an issue as long as V=<16V.  caps should be able tolerate full rated V.  rated unloaded is 7.6VAC max plus a cap and minus diode losses.  you may get a goosed V on power up, but nothing i would worry about if transient.  the Panny FM are workhorses and spec great.


----------



## DingoSmuggler

fishski13 said:


> i will measure across C5, but i don't forsee an issue as long as V=<16V.  caps should be able tolerate full rated V.  rated unloaded is 7.6VAC max plus a cap and minus diode losses.  you may get a goosed V on power up, but nothing i would worry about if transient.  the Panny FM are workhorses and spec great.


 
 With the 6VAC you'd just need to make sure minimum voltage under load is high enough so your dropping enough volts through the linear reg. On paper there should be plenty of headroom though measuring is certainly better.
  
  
 Come production time... I've just remembered I've got a NOS SEGA 10Vdc _linear_ plugpack, that should be well suited to this - maybe even crack it open to get an AC output. It never had a chance to power a mega drive, but it might get a chance to power a doodlebug.


----------



## Avro_Arrow

dingosmuggler said:


> With the 6VAC you'd just need to make sure minimum voltage under load is high enough so your dropping enough volts through the linear reg. On paper there should be plenty of headroom though measuring is certainly better.
> 
> 
> Come production time... I've just remembered I've got a NOS SEGA 10Vdc _linear_ plugpack, that should be well suited to this - maybe even crack it open to get an AC output. It never had a chance to power a mega drive, but it might get a chance to power a doodlebug.


 

 Yes, the taget minimum voltage at C5 is 7 volts DC.
 That gives enough headroom for the regulator to do it's job.


----------



## fishski13

i missed that point entirely.  hopefully the unloaded wart is putting out at least 6.4VAC or so then.  6.4*1.4142 = 9.1, or 7ish minus 2V diode drop.  i should receive the wart and other components in the the mail today.


----------



## Avro_Arrow

I think, in reality, the diodes only drop about 1.2 to 1.4 volts when

 more lightly loaded like they are here. Even if the adapter drops
 to 6 VAC when loaded, it should still be able to hit the minimum
 7 VDC at C5. All assuming a maximum 500mA current draw.
  
 6 * 1.4142 = 8.4852 so you can loose 1.5 volts and still be OK.
 Also, the 317 really only needs about 1.5 volts to do its job.
 2 volts just is a safer margin...


----------



## tomb

UPS says they're delivering both the connectors and resistors/caps/ferrites tomorrow.  So, I should be able to get them in the mail to you all on Tuesday.  Sometimes UPS changes their minds, though, and sends me an update saying it'll be a day later.  I'll keep you posted.


----------



## fishski13

stuffed the PS circuit.
  
 getting 7.7VAC from the T1124-P5-ND wall wart.  voltage at C5 is 8.9VDC.  at 200mA and 3.65 voltage drop at 5.25V output, that's 0.73W or so dissipation.


----------



## tomb

Sell, as I suspected - UPS was wrong.  Maybe tomorrow.


----------



## dBel84

I haven't stuffed my board yet - ended up going to the Bay area meet which was just magnificent. Planning on getting it done in the next day or so , looking forward to seeing how this impacts the O2. 
  
 and thanks for the xtra bits TomB - I didn't even think to check ( which is a major fail on my part - this is how we catch tired brain phenomenon )


----------



## tomb

You're welcome, dBel!
  
 OK - everyone's parts were shipped this morning:

The correct right-angle USB - A jack
L1, L2, L3, L4 - properly rated
C8
R5


----------



## tomb

I replaced the connector on mine and it works flawlessly!


----------



## Avro_Arrow

tomb said:


> I replaced the connector on mine and it works flawlessly!


 

 Good to hear Tom!
  
 Now you can torture it...


----------



## Ikarios

Checking in with interest here. Any possibility on getting this integrated with the pupDAC at any point in the future? Looks lovely.


----------



## muskyhuntr

Welp, finished populating my board.  Had absolutely no problems working on the digital side.  Even J1 went in/on without a hitch. The good news is that it fired up first time.  Plugging just the Doodlebug into my computer yielded nothing, as it should.  Next, plugged in my Y1  and  it's power LED lit (a red toggle switch).  Finally ran some tunes through JRiver.  Indicator went to green!  I used a Mini3 and my Senn HD600s for listening tests. 
  
 How did it sound?  In a word, better.  I use the Mini3/Y1 combo quire a bit so I am familiar with its signature.  The most predominate thing I noticed was an increase in clarity followed by a slight improvement in bass.  I am not talking leaps and bounds here, but definitely a notch better. 
  
 A few pages back, I made some suggestions for the power supply portion of the board, I still think they warrant a look (esp. an aux.  5V output jack.  I think that it would make the device a bit more useful).  Other than J1, I think the digital side of the board is right on.
  
 I do have some bad news, but it too is followed by some good news.  For the life of me, I could not find the caps I ordered for C1.  So I did my testing without it.  The good news is that it worked flawlessly without it.  It gets populated on my next order.
  
 One question, will this board fit into the cases you plan to offer?
  
 Thanks for the opportunity,
 Jim


----------



## tomb

muskyhuntr said:


> Welp, finished populating my board.  Had absolutely no problems working on the digital side.  Even J1 went in/on without a hitch. The good news is that it fired up first time.  Plugging just the Doodlebug into my computer yielded nothing, as it should.  Next, plugged in my Y1  and  it's power LED lit (a red toggle switch).  Finally ran some tunes through JRiver.  Indicator went to green!  I used a Mini3 and my Senn HD600s for listening tests.
> 
> How did it sound?  In a word, better.  I use the Mini3/Y1 combo quire a bit so I am familiar with its signature.  The most predominate thing I noticed was an increase in clarity followed by a slight improvement in bass.  I am not talking leaps and bounds here, but definitely a notch better.
> 
> ...


 

 Sounds great!
  
 Yes, I don't think Avro has changed anything from the standpoint of the connectors with regard to case-fit.  That's what would make a difference with a custom case.  It should stand as the guide for the case-design, as is.  You'll have to file that sprue left from breaking the boards apart, but other than that, it shouldn't change.
  
 I'll be drawing up the case design in the next couple of weeks, so maybe I'll have something more definite to show.


----------



## tomb

ikarios said:


> Checking in with interest here. Any possibility on getting this integrated with the pupDAC at any point in the future? Looks lovely.


 

 Sorry, but I don't think we have any intent to make something like a 2-PCB integration in the same case.  If it's possible as is, then go for it.  However, the DoodleBug is a complete device on its own and while my personal choice is always pairing it with a PupDAC 
	

	
	
		
		

		
			





 , I think we want the applicability to be as wide as possible (ODAC, GrubDAC, SkeletonDAC, Y1, etc.).  It's very easy to plug into an existing arrangement with the PupDAC and other USB-powered DACs with only one extra mini-USB cable.
  
 If possible, I'll try to locate the mini-USB cables that are only an inch or two long, so that the arrangement with a PupDAC could resemble the short interconnects that people use with portable iPod/amplifier connections.  I have one that came with a Seagate portable drive, so maybe they're mass-produced somewhere and available for purchase.


----------



## JacobLee89

tomb said:


> If possible, I'll try to locate the mini-USB cables that are only an inch or two long, so that the arrangement with a PupDAC could resemble the short interconnects that people use with portable iPod/amplifier connections.  I have one that came with a Seagate portable drive, so maybe they're mass-produced somewhere and available for purchase.


 
  
 There's always the fun of DIY'ing USB cables 
	

	
	
		
		

		
		
	


	



  
 Just imagine a project called " STUBBY USB CABLE! "


----------



## Mullet

This project looks super cool. I'll probably build one for my PupDAC. I recently built a DAC that employs USB isolation and it sounds great. A few questions...
  
 1) Is there a possibility of using external battery power with this? If so, what would be required?
  
 2) This one might not be able to be answered yet... For the guys who use a Gamma 1/2 is there a benefit to this being that it already has the option for an external 5v supply?


----------



## DingoSmuggler

mullet said:


> This project looks super cool. I'll probably build one for my PupDAC. I recently built a DAC that employs USB isolation and it sounds great. A few questions...
> 
> 1) Is there a possibility of using external battery power with this? If so, what would be required?
> 
> 2) This one might not be able to be answered yet... For the guys who use a Gamma 1/2 is there a benefit to this being that it already has the option for an external 5v supply?


 
 1. Sure, you'd need a battery capable of maintaining over 9V at whatever current your USB load is going to draw, for however long to want it to work - so likely something fairly hefty.
 The power supply on the doodlebug in it's current form won't be overly efficient for battery use. It will draw 10-20mA or so through the LEDs depending on the exact devices and where you set the output voltage. But with some component changes you could get this down to 1-2mA at the expense of possibly raising the noise floor a tiny amount.
  
 2. It depends on whether or not an isolated ground will give any rewards. Some computers (especially laptops) have noisy ground rails and this will get into the analog output of your DAC if it has the digital and analog grounds connected. If there isn't a problem with a noisy ground, or ground loop(s), then a full USB isolator shouldn't offer any benefit compared to power only, everything else being equal.


----------



## Avro_Arrow

Thank you everyone who have provided your valuable comments so far.
  
  
 The intent of the isolator is to: 
 1. Break any ground loop to reduce noise.
 2. Provide ample, quiet power.
  
 The isolator will not guarantee an audible improvement in all situations.
 However, in situations where a USB DAC is struggling, it can provide
 a dramatic improvement.
  
 It can be run from a battery, however it was never designed to be
 power efficient. A 7.2 vdc battery would work if the bridge rectifier
 is not used, a 9.6 to 12 volt battery would be needed if the bridge
 rectifier is left in place. You would want at least a 2 A/H battery
 capacity to get reasonable run time.
  
 While adding a DC output jack may seem like a value add, I feel
 it may cause confusion with some user and could result in equipment
 damage. For those who wish to hack, 5 vdc is conveniently available
 from the test points on the board. This also bypasses the 500mA
 fuse.
  
 The two LED's are used to set the output voltage and give the
 design very low noise compared to other LM317 designs.
 It should be possible to use one as a power indicator, but
 this has not been tested and the extra lead length may lead
 to unpredictable results. Again, a power LED could be added
 at the test points if two LED's inside the case are not enough.


----------



## TheShaman

avro_arrow said:


> It should be possible to use one as a power indicator, but
> this has not been tested and the extra lead length may lead
> to unpredictable results.


 

 One can easily get cheap fibers from eBay or elsewhere; they can be used to transfer the LED's light to the front panel. I use this method extensively in my builds.
 Much easier than messing with wires etc and can be tweaked to get the brightness you want without having to adjust current.


----------



## Avro_Arrow

theshaman said:


> One can easily cheap fibers from eBay or elsewhere; they can be used to transfer the LED's light to the front panel. I use this method extensively in my builds.
> Much easier than messing with wires etc and can be tweaked to get the brightness you want without having to adjust current.


 

 Excellent idea


----------



## fishski13

i dusted off my y2 and found that the USB is a bit flaky sans Doodlebug - one of my first SMD builds from years ago.  i'm ordering a new PCM2707, but no guarantees this will be the fix.  i'm borrowing an ODAC that should be here by Fri and i will be able to report back with impressions this weekend.


----------



## glunteer

Following the thread, and waiting for the final project to buy one


----------



## fishski13

got the ODAC loaner yesterday and powered up via the Doodlebug.  will post impressions soon.


----------



## fishski13

running off a dedicated USB PCI on my desktop without other devices connected, into either a B22 or QRV-08, and AD2000 or modded T50RP headphones, the ODAC is etched, bright, rough and harsh.  makes the BM DAC1 i recently sold after 6 years of enjoyment sound warm, smooth, and analog.  with the Doodlebug inserted, less bright/etched and more fleshed out.  more details and more natural sounding.  still not my cup of coffee, but the Doodlebug is an improvement in my rig.  
  
 maybe my desktop USB power really sucks, or the implementation of the secret sauce Sabre is black magic.  either way, isolation and clean power brings improvements.
  
 huge props to A_A and tomb.
  
 from a build perspective, the pads are generous and require a little extra heat.  high quality board and a perfect first time SMD project.


----------



## JacobLee89

fishski13 said:


> running off a dedicated USB PCI on my desktop without other devices connected, into either a B22 or QRV-08, and AD2000 or modded T50RP headphones, the ODAC is etched, bright, rough and harsh.  makes the BM DAC1 i recently sold after 6 years of enjoyment sound warm, smooth, and analog.  with the Doodlebug inserted, less bright/etched and more fleshed out.  more details and more natural sounding.  still not my cup of coffee, but the Doodlebug is an improvement in my rig.
> 
> maybe my desktop USB power really sucks, or the implementation of the secret sauce Sabre is black magic.  either way, isolation and clean power brings improvements.
> 
> ...


 
  
 I guess the ODAC's perceived brightness bumps the HD650's subdued highs, which is probably why people enjoy the objective stack + HD650's.
  
 I've recently installed the output booster mod on my O2, which has made it more "musical", I can imagine that with doodlebug working on the ODAC, the changes would be noticeable on my setup.
  
 Count me in as an interested patron, whenever the next batch is ready!
  
 Out of curiosity (question open to anyone knowledgeable), would it be of any benefit to put a ferrite core on the cable from the doodlebug to the ODAC?


----------



## tomb

jacoblee89 said:


> fishski13 said:
> 
> 
> > running off a dedicated USB PCI on my desktop without other devices connected, into either a B22 or QRV-08, and AD2000 or modded T50RP headphones, the ODAC is etched, bright, rough and harsh.  makes the BM DAC1 i recently sold after 6 years of enjoyment sound warm, smooth, and analog.  with the Doodlebug inserted, less bright/etched and more fleshed out.  more details and more natural sounding.  still not my cup of coffee, but the Doodlebug is an improvement in my rig.
> ...


 

 No.  IMHO, that was a Band-Aid patch on the ODAC to cover up the misfortune that it was designed without any power capacitors.  There is _no_ electrolytic capacitor on the ODAC.


----------



## tomb

dingosmuggler said:


> mullet said:
> 
> 
> > This project looks super cool. I'll probably build one for my PupDAC. I recently built a DAC that employs USB isolation and it sounds great. A few questions...
> ...


 
 2. I'm treading on very thin ground here, because I respect AMB and all of his designs.  However, to suggest that the ground is noisy, but the voltage side is not, seems a bit of conjecture.  If the noise exists, the voltage side is always referenced against the ground, so there's no way that one would be "contaminated" and the other not. (They both come through rectification equally to form the DC plus and minus references.)
  
 There is some support in the conjecture when it comes to _PCB layouts_ that convert AC to DC.  In those cases, I agree that as little of a connection to ground from the AC side to the DC side is best.  However, _the connected ground is always less noisy _than the non-connected ground.  I speak from experience in the months and months of experimentation and measurements that Colin Toole and I did on the Millett Hybrid MAX and MiniMAX designs.  The original completely deleted the ground plane.  Later versions connected the ground plane.  Finally, ground planes that were minimally connected had the least noise.  We went from _most noise _(no AC ground plane) to _less noise_ (ground planes contiguous) to _least noise _(ground planes minimally connected).
  
 In the case of the DoodleBug, we're talking about cleaning up DC that already exists, period.  Trash is on both sides of the voltage differential.
	

	
	
		
		

		
			





 
  
 EDIT:  As you may see from my future posts, I think the difference lies in the sophistication of the DAC.  For instance, does the design depend on numerous regulators throughout the design, or is everything sort of taken as is, and the basic performance of the DAC chip implemented as simply as possible?  I think the small testing I did shows that sophisticated DACs can make very good use of the DoodleBug for a greatly increased performance.  On the other hand, those DACs that are simplest in nature (simplified DAC chips, very limited onboard regulation) don't have the resources in the circuit design to take advantage of the DoodleBug.


----------



## tomb

http://www.diyforums.org/Doodlebug/tests/SkeletonDAC-DoodlebugComparison.htm
http://www.diyforums.org/Doodlebug/tests/PupDAC-DoodlebugComparison.htm
http://www.diyforums.org/Doodlebug/tests/Comparison-Doodlebug-all.htm
  
 The links above are self-explanatory.  They're also available on the main prototype web page, here:
http://www.diyforums.org/Doodlebug/tests/Comparison-Doodlebug-all.htm
  
 What you will see is a not-so-much improvement on a very simple DAC, the SkeletonDAC.  Nevertheless, the improvement is there and was measured.  However, for a sophisticated DAC like the PupDAC, you'll see that the improvement is both large and significant.  Noise and dynamic range approach the virgin specs of the PCM1794, which is 129dB.  Distortion, both THD and IM, were improved by entire magnitudes:
  
 NOISE LEVEL:

  
 DYNAMIC RANGE:

  
 THD + NOISE:

  
 IM DISTORTION:

  
 Finally, CROSSTALK:

  
 Basically, performance across the entire range of measurements were improved with the DoodleBug.  More than that, my entire testing regime was improved.  The reason for that is that the M-Audio Transit that I've used all of these years was also USB-powered.  The typical testing source that I used was the same thing I would take to meets: a couple of Acer NetBooks.  It is more than obvious now that I have been working under a sub-standard environment to both test and demonstrate Beezar DACs.  Sorry to mention AMB again, but all this time I thought it was his suggestion that my cables were not shielded enough, or that my house contained too much Wi-Fi and wireless telephones, and that none of this was done in a steel enclosure.
  
 With the DoodleBug, I've proved to myself that it was the substandard USB and power connection to the M-Audio Transit.* 
	

	
	
		
		

		
		
	


	




 
  
  
 * For all of these tests, I had a DoodleBug on the M-Audio Transit at all times.  The tests were then conducted with the DACs fed directly from the Netbook USB or from another DoodleBug interjected between the DAC and the Netbook.  It looks like I will have to re-run tests on all Beezar's products, because the noise level is so much lower with the tests on the M-Audio Transit equipped with the DoodleBug.
  
 This has literally been a revelation.


----------



## DingoSmuggler

tomb said:


> 2. I'm treading on very thin ground here, because I respect AMB and all of his designs.  However, to suggest that the ground is noisy, but the voltage side is not, seems a bit of conjecture.  If the noise exists, the voltage side is always referenced against the ground, so there's no way that one would be "contaminated" and the other not. (They both come through rectification equally to form the DC plus and minus references.)
> 
> There is some support in the conjecture when it comes to _PCB layouts_ that convert AC to DC.  In those cases, I agree that as little of a connection to ground from the AC side to the DC side is best.  However, _the connected ground is always less noisy _than the non-connected ground.  I speak from experience in the months and months of experimentation and measurements that Colin Toole and I did on the Millett Hybrid MAX and MiniMAX designs.  The original completely deleted the ground plane.  Later versions connected the ground plane.  Finally, ground planes that were minimally connected had the least noise.  We went from _most noise _(no AC ground plane) to _less noise_ (ground planes contiguous) to _least noise _(ground planes minimally connected).
> 
> ...


 
 I'm think you may have read way to much into my post, I'm a bit confused by your reply.
  
 If were talking about non-bus-powered DACs then only the ground is connected, not the 5V. The doodlebug will simply provide an isolated ground, which will only help when there's an issue. (not talking about internal grounding schemes at all)


----------



## JacobLee89

tomb said:


> No.  IMHO, that was a Band-Aid patch on the ODAC to cover up the misfortune that it was designed without any power capacitors.  There is _no_ electrolytic capacitor on the ODAC.


 
 Thanks  
	

	
	
		
		

		
		
	


	



  
 I'm also interested on the "spikes" found on the 1k mark on the charts "dynamic range" and "THD and noise" for the doodlebug tests. I'm quite new to reading these types of charts and can't quite make sense of them.


----------



## tomb

dingosmuggler said:


> tomb said:
> 
> 
> > 2. I'm treading on very thin ground here, because I respect AMB and all of his designs.  However, to suggest that the ground is noisy, but the voltage side is not, seems a bit of conjecture.  If the noise exists, the voltage side is always referenced against the ground, so there's no way that one would be "contaminated" and the other not. (They both come through rectification equally to form the DC plus and minus references.)
> ...


 

 Yes - I didn't realize that you were talking about externally-powered DACs.  I think the original question was y1/y2, so I took that to also mean the power options available,  one of which is USB-powered (or even a walwart, only).  If someone used a Sigma25 or similar, then yes, I agree completely that the difference from the power side of the DoodleBug would probably be negligible.
  
 Realize also that there's been debate in the past about whether to connect the USB shield (and connector) through the cable to the DAC's PCB ground.  I thought perhaps some of that was implied in your post, too.
  
 Sorry that I misinterpreted.


----------



## tomb

jacoblee89 said:


> tomb said:
> 
> 
> > No.  IMHO, that was a Band-Aid patch on the ODAC to cover up the misfortune that it was designed without any power capacitors.  There is _no_ electrolytic capacitor on the ODAC.
> ...


 

 RMAA uses a 1K carrier signal.  Unless the testing software specifically filters it out (RMAA doesn't), you'll see it on every USB DAC/device:  The same thing occurs on the IM plot at 60Hz.
  
 Here's AMB's y1 THD plot (Config. B):

  
 y1's IM distortion plot (Config. B):


----------



## mcandmar

Hi Tomb,
  
 Nice to see somebody quantifying the difference an isolator/clean power source can make, nice work. For me it verifys what i found with my own two ears, always good to know it wasn't my imagination after all.
  
 Quote:


> Realize also that there's been debate in the past about whether to connect the USB shield (and connector) through the cable to the DAC's PCB ground.  I thought perhaps some of that was implied in your post, too.


 
  
 In relation to the above, if you study the ODAC you will find the USB shield is not connected to the circuit, however there is an unpopulated solder pad to do so which implys to me the designer was in two minds about it, but ultimately decided to leave it disconnected in the end.  I dont see the need for it personally unless you are using a battery powered device and want its power supply ground referenced.


----------



## KimLaroux

Oh, that's a very exciting project. Great to see the objective measurements backing up the theory. I'm blown by the improvements made by this simple circuit. (forgetting the complexity of whatever is inside the chip.)
  
 But it seems a bit counter-intuitive that simpler DACs will see less improvements than more complex ones. One would think that DACs with better PSUs would be less affected by the quality of their supply. Unless it's not a matter of clean supply, but supply overload or outright data noise.
  
 Have you tested it with the grubDAC? I'm curious if this would improve the performance of a grubDAC+Carrie.


----------



## tomb

kimlaroux said:


> Oh, that's a very exciting project. Great to see the objective measurements backing up the theory. I'm blown by the improvements made by this simple circuit. (forgetting the complexity of whatever is inside the chip.)
> 
> *But it seems a bit counter-intuitive that simpler DACs will see less improvements than more complex ones. One would think that DACs with better PSUs would be less affected by the quality of their supply. Unless it's not a matter of clean supply, but supply overload or outright data noise.*
> 
> Have you tested it with the grubDAC? I'm curious if this would improve the performance of a grubDAC+Carrie.


 
 I think simpler DACs probably have nowhere to go in performance.  Not to insult everyone's favorite cheap tube amp, but it's sort of like the Starving Student.  Once the inherent noise in the tube circuit exceeds the switcher power supply, there's little performance gain achieved by substituting a better power supply.
  
 Beezar is moving this month.  Unfortunately, all of my GrubDACs are packed and I can't get to them right now. 
	

	
	
		
		

		
		
	


	




  However, I suspect the results would be somewhere in-between that of the SkeletonDAC and the pupDAC, because the GrubDAC has an onboard regulator.


----------



## KimLaroux

tomb said:


> I think simpler DACs probably have nowhere to go in performance.  *Not to insult everyone's favorite cheap tube amp, but it's sort of like the Starving Student.  Once the inherent noise in the tube circuit exceeds the switcher power supply, there's little performance gain achieved by substituting a better power supply.*
> 
> Beezar is moving this month.  Unfortunately, all of my GrubDACs are packed and I can't get to them right now.
> 
> ...


 
  
 I really have no idea what's you're talking about.
  
 LOL 
	

	
	
		
		

		
		
	


	




 
  
 But the next question is, would the Carrie gain performance?
  
 But then it would be ironic to add a wall-wart and a middle-man to a two-in-one whose meaning of existence is to be small and solely powered by USB.
  
 Have fun moving.


----------



## dBel84

A little late to the party - picked up a bug and only just got round to building this little gadget. 
  

  
  

  
  
 came up perfectly and just needs the end plates drilled / cut. 
  
 I will have to test it with the ODAC tomorrow. None of the dacs I have at home will likely see much benefit 
  
 Thanks TomB and A_A
  
 ..dB


----------



## tomb

kimlaroux said:


> tomb said:
> 
> 
> > I think simpler DACs probably have nowhere to go in performance.  *Not to insult everyone's favorite cheap tube amp, but it's sort of like the Starving Student.  Once the inherent noise in the tube circuit exceeds the switcher power supply, there's little performance gain achieved by substituting a better power supply.*
> ...


 





 I thought you might appreciate the analogy.
  
 Yes, I suspect that something built on the principle of boosting USB power would benefit greatly from the DoodleBug.  As you say, though, it maybe has diminishing returns in the semi-portable environment the Carrie was addressing.
  
 Of course, all of this assumes one is trying to achieve as much as the particular component is capable of attaining.  In what I read recently from some of Tyll's articles, maybe it's the difference between Mid-Fi and Hi-Fi.  I will readily admit that perhaps Beezar is on the cusp of making that level change.


----------



## tomb

dbel84 said:


> A little late to the party - picked up a bug and only just got round to building this little gadget.
> 
> 
> 
> ...


 

 Looking great so far!!


----------



## earfanatic

Hi There!
  
 I would like to build one as well.
 How can I get it? Is it already available?
 thx


----------



## jboehle

Subscribed!  I plan to start building my pupDAC tonight, this sounds like a great upgrade!


----------



## tomb

earfanatic said:


> Hi There!
> 
> I would like to build one as well.
> How can I get it? Is it already available?
> thx


 

 We're working on it. 
	

	
	
		
		

		
		
	


	




  As with all Beezar products, the build information will be on diyforums.org.  I hope that doesn't get deleted, because the actual forum section is pretty much inactive.  Head-Fi is the primary forum resource.


----------



## tomb

Production PCB's were ordered today.  I hope to have the website up and running in a few weeks, but this has to be tempered with Beezar's move.  I'll do my best.


----------



## Jasper9395

tomb said:


> Production PCB's were ordered today.  I hope to have the website up and running in a few weeks, but this has to be tempered with Beezar's move.  I'll do my best.


 

 Sweet! Can you give us an indication of the pricing?


----------



## tomb

jasper9395 said:


> tomb said:
> 
> 
> > Production PCB's were ordered today.  I hope to have the website up and running in a few weeks, but this has to be tempered with Beezar's move.  I'll do my best.
> ...


 

 PCB's will most likely be $10.  Kits can be figured out from the BOM + PCB price.  I don't know that off the top of my head, but Beezar never prices anything in conflict with the BOM - at least for a kit.  Casework is yet to be determined.  As many of you know, that can cost almost 50% of the cost of the total device.  I will try to keep the prices down and will always endeavor to offer a "short kit" without the case if it is feasible.
  
 The PupDAC case will be almost a total equivalent - no more, no less, so you can use that as a guide for the case work.  Obviously, one purchasing everything including the case will save money over purchasing everything separately.  Also, please remember that some people have successfully sold similar projects using the same case but with $45 just for Front Panel Express endplates.  The PupDAC does better than that and I feel certain that the DoodleBug will, too.*
  
  
 * The idea is to have a red-anodized Hammond 1455C801 with laser-etching similar to the PupDAC, only with the DoodleBug logo that DingoSmuggler developed.  The way things work in sales, these days, though, I'll probably do half-and-half, red cases and black cases.  Seems like everyone wants black, no matter what it is. 
	

	
	
		
		

		
		
	


	



  
 ** The PCBs will be red, period.
  
 Opinions?


----------



## Jasper9395

Sounds good. I think there should definitely be the option of buying the kit without a case. This being a DIY project people are going to be looking to keep cost down. Also, many of us probably don't mind making our own. I do like your idea of doing a red case similar to the PubDAC though, think it will look nice.


----------



## jboehle

Love the idea of a red case to go with the blue pupDAC, but of course those are the colors of my favorite university as well


----------



## Jasper9395

Just a quick question. Will using the Doodlebug with a USB > SPDIF converter improve the sound from my DAC?


----------



## tomb

jasper9395 said:


> Just a quick question. Will using the Doodlebug with a USB > SPDIF converter improve the sound from my DAC?


 

 If the DAC is using power from the USB, then I would say, YES - absolutely.  If that's not the case and you're looking for a benefit simply from an improved USB data stream - I don't know.  Avro will have to answer that one.  Just one thing - I can't see how it wouldn't improve any USB-streaming connection, period, no matter the device.  The question is how much of an improvement.  We've shown that for some devices, it's significant and measurably demonstrated.  For others, not so much.


----------



## Jasper9395

tomb said:


> If the DAC is using power from the USB, then I would say, YES - absolutely.  If that's not the case and you're looking for a benefit simply from an improved USB data stream - I don't know.  Avro will have to answer that one.  Just one thing - I can't see how it wouldn't improve any USB-streaming connection, period, no matter the device.  The question is how much of an improvement.  We've shown that for some devices, it's significant and measurably demonstrated.  For others, not so much.


 
 In my case the DAC its self is not powered by USB the only the USB > SPDIF converter is.
  
 The question of data stream is interesting and I think you are right that it should improve. I used to keep most of my music on an external hard drive which had an external power supply. When I was playing music directly from my notebook where files were stored on SSD I noticed a positive change... My guess is that the power supply on the external drive was introducing noise.


----------



## Avro_Arrow

jasper9395 said:


> Just a quick question. Will using the Doodlebug with a USB > SPDIF converter improve the sound from my DAC?


 

 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.


----------



## Jasper9395

avro_arrow said:


> 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
> ...


 

 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

spiral out said:


> 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

tomb said:


> 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..


----------



## Avro_Arrow

A little project update:
  
 We got the production boards back.
 However, Tom moved and this has prevented any
 progress for the time being. As we all know, life tends
 to get in the way of our hobbies from time to time.
 I'm sure Tom will be back with us as soon as practical.
  
 Just a little while longer...


----------



## tomb

avro_arrow said:


> A little project update:
> 
> We got the production boards back.
> However, Tom moved and this has prevented any
> ...


 

 Yes - thanks for that, Avro!  And thank everyone else for their patience!  The DoodleBug is at the top of my project priority list and I will get on it as soon as I can!  Long-term, the new location is going to enhance my productivity by several-fold, but a new house is one of those life-changing events that comes with many un-predictable challenges.  For instance, it's been three separate days/trips by the cable guys to get everything connected at the new house - cable, network, phones.  One day the TV's work, but the network doesn't.  Next day, the network is OK, but the phones don't work.  Then my printers don't work because they setup an entirely different private network address system than the one I used before.  It's one thing after another, but it's getting better gradually.


----------



## JacobLee89

tomb said:


> Yes - thanks for that, Avro!  And thank everyone else for their patience!  The DoodleBug is at the top of my project priority list and I will get on it as soon as I can!  Long-term, the new location is going to enhance my productivity by several-fold, but a new house is one of those life-changing events that comes with many un-predictable challenges.  For instance, it's been three separate days/trips by the cable guys to get everything connected at the new house - cable, network, phones.  One day the TV's work, but the network doesn't.  Next day, the network is OK, but the phones don't work.  Then my printers don't work because they setup an entirely different private network address system than the one I used before.  It's one thing after another, but it's getting better gradually.


 
  
 Good luck on setting up the new place, and hope the equipment decides to behave soon! I've had my share of network troubleshooting


----------



## tomb

jacoblee89 said:


> tomb said:
> 
> 
> > Yes - thanks for that, Avro!  And thank everyone else for their patience!  The DoodleBug is at the top of my project priority list and I will get on it as soon as I can!  Long-term, the new location is going to enhance my productivity by several-fold, but a new house is one of those life-changing events that comes with many un-predictable challenges.  For instance, it's been three separate days/trips by the cable guys to get everything connected at the new house - cable, network, phones.  One day the TV's work, but the network doesn't.  Next day, the network is OK, but the phones don't work.  Then my printers don't work because they setup an entirely different private network address system than the one I used before.  It's one thing after another, but it's getting better gradually.
> ...


 

 Thanks!  Still working - maybe some progress on the DoodleBug this weekend, I hope.


----------



## firev1

Joining in to register my interest, would love to see a kit in the near future


----------



## Soundsgoodtome

I have interest in an isolator, subbed


----------



## laon

I hope this turn into commercial product, even with just hifimediy one the difference is very noticeable.


----------



## Soundsgoodtome

Edit


----------



## scootsit

I'm assuming that adding an external power source will allow use with USB On the go for mobile devices. That's pretty exciting. I use my phone to listen at work, and I'd love to use my pup or grub with it.


----------



## Avro_Arrow

scootsit said:


> I'm assuming that adding an external power source will allow use with USB On the go for mobile devices. That's pretty exciting. I use my phone to listen at work, and I'd love to use my pup or grub with it.


 

 I think it should work fine.
 You can also run the Doodlebug off a 7.2 volt RC car battery...


----------



## jboehle

Any update on this, tomb?  I have been experiencing some intermittent audio drops with one of my MacBook Pros and the pupDAC.  I have been using the analog headphone out from the MacBook Pro the last few days instead, feeding into my headphone amps and have not had the same issue.  This sounds like the USB power issues the Doodlebug is supposed to solve.


----------



## tomb

jboehle said:


> Any update on this, tomb?  I have been experiencing some intermittent audio drops with one of my MacBook Pros and the pupDAC.  I have been using the analog headphone out from the MacBook Pro the last few days instead, feeding into my headphone amps and have not had the same issue.  This sounds like the USB power issues the Doodlebug is supposed to solve.


 

 I'm working on the CAD drawing for the case design right now.
  
 EDIT: Should have some dimensions to post later today ...


----------



## Soundsgoodtome

I'm excited to try different external power units for this. Wonder if there will be audible differences between power units on something like an ODAC or Modi.


----------



## Avro_Arrow

soundsgoodtome said:


> I'm excited to try different external power units for this. Wonder if there will be audible differences between power units on something like an ODAC or Modi.


 

 One of the testers, earlier in the thread, did report an improvement in sound quality with their ODAC.
 I am also excited to hear back how it performs under all the different conditions it will be used in.


----------



## bootdsc

Can't wait to get my hands on one, this will be vary handy with my software defined radio RTL dongle and usb powered frequency converter. It picks up all kinds of noise from any computer its hooked to.


----------



## mcandmar

For those following this thread here is the difference i measured using a Doodlebug. I think the noise floor is a limitation of the sound card i was using to measure the results.


----------



## tomb

Very cool!  That's pretty similar to what I got awhile back - mine was maybe worse to start with, but that's because I've been using a POS netbook with an M-Audio Transit.  M-Audio quit making the Transit, I suspect because they couldn't keep up with the driver changes in follow-on Windows OS systems.  The little netbook is the only thing I have that still runs Windows XP and the Transit works fine under that.  The USB power system in the netbook, however, is another thing entirely.


----------



## tomb

I've finally been doing some work (pdf downloads available by clicking):
  






  
 Hammond has been contacted and they're working on a quote for case work (1455C801), so we should be able to get cases going soon.  Next up is the website and a production proto.  I'll continue to report on the progress - hopefully, it won't be too many more weeks before we have kits available.


----------



## Avro_Arrow

tomb said:


> I'll continue to report on the progress - hopefully, it won't be too many more weeks before we have kits available.


 

 Great job Tom, keep up the good work!


----------



## SilverEars

Hi, why does pupDAC pick up so much noise compared to skeletonDAC?


----------



## tomb

silverears said:


> Hi, why does pupDAC pick up so much noise compared to skeletonDAC?


 
  

It depends on how much noise already exists on the particular PC USB buss.
It's a much more sensitive, detailed DAC.  Some of the noise is masked by the lower-grade chip in the SkeletonDAC
The output opamp in the PupDAC is one of the finest low-voltage opamps on the market.  Strictly speaking, it's not there for amplification, but for combining the balanced output of the DAC chip into a single-ended output.  Nevertheless, it's going to amplify every detail.  If that detail is noise, it's going to get amplified, too  There's probably more going on with the balanced-to-single-ended conversion, too, but I'm not knowledgeable enough about that to explain it.
Another way to look at it, is that the potential of the PupDAC is much, much higher.  It just needs a reasonably good environment to ensure the best performance. 
  
 In my case, the power supply of my testing environment is probably as bad as it could get and still provide operation (Acer Netbook running Windows XP).  I have wondered for years why my RMAA tests were noisier, sometimes going as far as depending on other people to test Beezar products (dsavitsk, cetoole, cobaltmute, Linux-works of Arduino fame).  As mentioned previously, AMB once suggested that my cables were picking up extraneous noise in my environment, etc.  The entire exercise in testing the DoodleBug has proven what's really happening.
  
 Anyway, in an environment other than the Acer Netbook, you will see a much better base performance for the PupDAC without the DoodleBug. I would still recommend the DoodleBug for any USB-powered audio device, though.


----------



## firev1

Nice to see progress coming along! I posted on the ODAC thread about the possible benefits of USB isolation so I believe in their usage. As for testing, single laptops in my experience are really not idea for RMAA testing of these devices. What you really want ideally separate laptops for testing or in some others case, separating the interfaces(soundcard PCI and generator/DAC on USB). This is to avoid ground loop issues. I usually have 2 laptops on battery for testing.


----------



## SilverEars

tomb said:


> It depends on how much noise already exists on the particular PC USB buss.
> It's a much more sensitive, detailed DAC.  Some of the noise is masked by the lower-grade chip in the SkeletonDAC
> The output opamp in the PupDAC is one of the finest low-voltage opamps on the market.  Strictly speaking, it's not there for amplification, but for combining the* balanced output of the DAC chip into a single-ended output*.  *Nevertheless, it's going to amplify every detail.  If that detail is noise, it's going to get amplified, too*  There's probably more going on with the balanced-to-single-ended conversion, too, but I'm not knowledgeable enough about that to explain it.
> Another way to look at it, is that the potential of the PupDAC is much, much higher.  It just needs a reasonably good environment to ensure the best performance.
> ...


 
 Wouldn't you subtract out the noise with balanced?  If you have balanced outputs than you can subtract the noise before single ended output(like a differential signal line).  Since you have two set of signal lines, noise will be the same for each set of signal lines, and you can phase shift 180 and take the sum of the sets of signal lines, and take out the noise. All amps amplify noise, but some have better SNR, no?
  
 So, I don't really understand why the single ended will have noise at the output if the balanced amps are picking up that much noise if differential mode is implemented.
  
 Well, the doodlebug is suppose to take out PS noise.  How is the noise from amp related to PS noise?


----------



## tomb

silverears said:


> tomb said:
> 
> 
> > It depends on how much noise already exists on the particular PC USB buss.
> ...


 
  
 The cancelling effect with balanced circuits is a very theoretical abstract.  Yes, all things being equal - balanced drive inherently cancels even-ordered harmonic distortion - but not odd-ordered distortion, IM or power supply noise.  You can have power supplies interjecting signals at many given frequencies - 60 Hz, 120 Hz, 180 Hz, etc. - even higher with switching supplies, etc.  If the amplification section operates with very low distortion, it doesn't mean that distortion is created from those signals or any others (but most likely it will), but they certainly will add to the noise.
  
 You need to re-phrase that last question or maybe my comments above answered it.
  
 P.S. I'm not sure we can discuss this further in any meaningful way when the entire premise is based on conjecture - my guess for why the SkeletonDAC shows little improvement with the DoodleBug.  Let's review what's really known:

The PupDAC is vastly superior in performance to the SkeletonDAC.
The PupDAC shows remarkable improvement using the DoodleBug, depending on the original quality of the USB power buss.  Most tests indicate that the worse the USB power buss quality, the greater the improvement.
The SkeletonDAC does not show as much improvement with the DoodleBug and performance is worse overall than the PupDAC.
  
 I'm not sure we can make absolute, definitive statements beyond that.


----------



## SilverEars

Thank you tomb.

  
 I was wondering if this is a good good as any power supplies that usually come with high-end DACs that have those fancy PS section with toroids and etc..
 I'm guessing you will have built ones for sale soon?


----------



## bada bing

Any updates ?


----------



## Avro_Arrow

I think Tom is still waiting on the prototype cases from Hammond.
 There is also the laser etching to prototype and approve.
 Should be soon.
 Boards and most kit parts are ready. I think there were a couple
 items that were back ordered.


----------



## tomb

avro_arrow said:


> I think Tom is still waiting on the prototype cases from Hammond.
> There is also the laser etching to prototype and approve.
> Should be soon.
> Boards and most kit parts are ready. I think there were a couple
> items that were back ordered.


 

 Yep - exactly.  I am awaiting Hammond's prototype case (1455C801) that's been machined for the DoodleBug.  Once I have that - and build one using the production board - we'll be ready to go.  Hopefully, I'll have the website done by then, too.  So ... not too much longer - I hope.


----------



## kugino

tomb said:


> Yep - exactly.  I am awaiting Hammond's prototype case (1455C801) that's been machined for the DoodleBug.  Once I have that - and build one using the production board - we'll be ready to go.  Hopefully, I'll have the website done by then, too.  So ... not too much longer - I hope.


 
 cool...looking forward to it!


----------



## kugino

any update, tomb?


----------



## tomb

kugino said:


> any update, tomb?


 

 Still waiting on the prototype case from Hammond ...


----------



## tomb

Just an update because I know many of you have been patiently waiting for the DoodleBug:
  
 1. We had an issue with the production PCB's.  It took us awhile to determine a fix and get that negotiated with Imagineering.  They've fixed them and are shipping them back to me, but I don't have them in hand yet - probably next week sometime.
  
 2. Meanwhile, I received the custom case sample from Hammond this week and carried it over to my anodizer.  I picked it up this morning, anodized in RED.  However, I then delivered it to the laser-etcher who will have it until probably Thursday.
  
 After that - or in-between - I'll build another using the production PCB and parts, see how it fits the case, then give Hammond the go-ahead to start production.
  
 I'll post some pics of the production sample when I get it built.
  
 I'm sorry that this is taking so long, but these things don't happen overnight.  Anyway, just thought I'd let you know that a lot of things continue to go on behind the scenes.


----------



## kugino

tomb said:


> Just an update because I know many of you have been patiently waiting for the DoodleBug:
> 
> 1. We had an issue with the production PCB's.  It took us awhile to determine a fix and get that negotiated with Imagineering.  They've fixed them and are shipping them back to me, but I don't have them in hand yet - probably next week sometime.
> 
> ...


No worries! Looking forward to seeing your build soon. It takes time to get things right so just keep chugging! Thanks.


----------



## tomb

Further update:
  
 I again apologize for this, it seems we've got teething problems all along with the DoodleBug - but nothing related to Avro's circuit or performance. 
	

	
	
		
		

		
		
	


	



  
 The first results from the laser-etcher were not acceptable, so I took it back for another round after revising the graphics.  The graphics were not really causing the problem, but they may have been exacerbating it.  Anyway - not to bore you with the details - but the reports tonight are good and I will pick up the prototype case again from the laser-etcher tomorrow.  Assuming that everything is fine, I'll turn on Hammond to do the production run of the cases.
  
 Meanwhile, I'll get the website built and then we should be good to go.  Thanks for your patience, everyone!


----------



## tomb

The laser-etching on the production cases will differ slightly, but this will give you a good idea of what it will look like:
  



  



  
 Hammond will be given the go-ahead on the production cases Monday.


----------



## muskyhuntr

Looks good!  Can't wait to put mine into one of those cases.
  
 Me


----------



## SilverEars

tomb said:


> The laser-etching on the production cases will differ slightly, but this will give you a good idea of what it will look like:
> 
> 
> 
> ...


 
Want.  
	

	
	
		
		

		
		
	


	




 Where can I throw money at it?


----------



## kugino

Looks pretty cool. Should be a fun little project...


----------



## DingoSmuggler

Looking good!
  
 I'm sure it will be worth the wait.


----------



## HiGHFLYiN9

Very nice Tomb


----------



## mcandmar

What, no blue?


----------



## jboehle

Any update?
  
 How does this compare to the Schiit Wyrd?  Same functionality?


----------



## tomb

jboehle said:


> Any update?
> 
> How does this compare to the Schiit Wyrd?  Same functionality?


 

 Cases are now finished and look fantastic!  Unfortunately, I'm in the process of upgrading Beezar to new software - to stop the US Post Office from breaking it all the time.  That's going to take me awhile, but I'm taking vacation the week of Labor Day.  The plan is to get the NEW Beezar up and running and to have the DoodleBug website built, too.  Hopefully, Beezar will have a lot more capability and more options, too.
  
 Then we'll be off and running!
  
 Schiit Wyrd?  Ours will be cheaper (and smaller), for sure - because you have to build it.  Complexity is probably less than the skills needed to build a GrubDAC, though, so should be within reach of anyone willing to try SMD.  I'd be curious to get more information about Schiit's design.  I note that they quote uV regulators, but it's carefully worded so as to _not_ state that's the entire unit's performance.  I'd be interested to see Avro's opinion if they supply a bit more information.  Certainly, the trend is going to toward enhancing USB-powered devices everywhere.  The differences are quite stark with a sophisticated USB-powered device.
  
 Anyway, our delays are the difference between a large concern and a couple of guys with an idea for DIY - they have the resources to overcome all the teething problems that Avro and I have had.


----------



## Avro_Arrow

jboehle said:


> Any update?
> 
> 
> How does this compare to the Schiit Wyrd?  Same functionality?


 

 I just had a look at the Wyrd.
  
 From what I can tell from the description, it is just a power supply, not an isolator.
 The wording, in fact, excludes it from being an isolator.
 What it is, if you can guess by the wording, is a hub with a fancy
 power supply.


----------



## SilverEars

If the usb supply is blocked, isnt that isolation?


----------



## Avro_Arrow

silverears said:


> If the usb supply is blocked, isnt that isolation?


 

 No, the ground is continuous.


----------



## skeptic

avro_arrow said:


> No, the ground is continuous.


 
  
 Thanks for explaining this Avro!  Coincidentally, I was just reading about the importance of USB ground plane isolation in John Swenson's 3 part series: http://www.audiostream.com/content/qa-john-swenson-part-2-are-bits-just-bits


----------



## preproman




----------



## tomb

That's a long time between bites of popcorn.


----------



## JacobLee89

Wondering if there's any more people whom tried the current doodlebug (whatever stage it is now) with the ODAC, and possibly how it may translate with the O2 + HD650.
  
 If not, I'd like to say that this is the only USB isolator that is keeping me interested. Far more so than the Schiit Wyrd probably due to the promise of a new DIY project


----------



## mcandmar

Not sure what exactly your asking but i can confirm it works fine with the ODAC.


----------



## JacobLee89

mcandmar said:


> Not sure what exactly your asking but i can confirm it works fine with the ODAC.


 
 Just posted to see if more ODAC's have been tested with the doodlebug. A wider variety of opinions on this combination will most likely make me impatient for my own doodlebug.
  
 Which is a good thing, perhaps.


----------



## DingoSmuggler

What's the latest on the availability of the doodlebug?


----------



## tomb

dingosmuggler said:


> What's the latest on the availability of the doodlebug?


 

 Counting down to the wire.  I have 95% of the website finished.  I'm hoping to make up a set of kits this weekend and have it listed on Beezar.


----------



## DingoSmuggler




----------



## tomb

The DoodleBug USB isolator website is now live:
*DoodleBug*
  
 Comments are welcome - there may be some typos. I will have the kits on sale at Beezar by Monday-Tuesday.


----------



## dBel84

I have been away for too long - that is an amazing looking case !! Great work on the website too ..dB


----------



## mcandmar

Website is top notch as always Tomb!


----------



## HiGHFLYiN9

Great work as always Tom! Congrats!


----------



## JacobLee89

Just out of curiousity, would this work on USB microphones? I keep on thinking that the signal path will only go one direction thanks to the doodlebug being in place.
  
 But that wouldn't make sense since the device "must" send information to the computer in order for it to recognise it as a device.
  
 I'm guessing that it will work?


----------



## Avro_Arrow

That depends. Is the USB Microphone a USB Low Speed, Full Speed or High Speed device?
 All USB devices use two way communication.


----------



## JacobLee89

avro_arrow said:


> That depends. Is the USB Microphone a USB Low Speed, Full Speed or High Speed device?
> All USB devices use two way communication.


 
  
 The only hint I can find to it's USB speed is on the manual: "USB audio class 2.0". Doesnt' say whether it's Full Speed or High Speed.
  
 *Edit: it's a Blue Yeti USB Microphone btw*
 *Edit 2: Educated myself. Since it supports USB Audio Class 2, it most likely means that it's the High Speed 480Mbps rate*


----------



## Avro_Arrow

What sample rates does it support?
 If the highest it goes is something like 24 bits and 96k then
 it's USB 2.0 Full speed.
 If it's higher, like 32 bits or 196k then it has to be USB 2.0 High speed.


----------



## Avro_Arrow

A quick search provided the answer.
  
 Yeti - Full Speed
 Yeti Pro - High Speed.
  
 So, yes, the Yeti will work with the Doodlebug.


----------



## tomb

I'm pleading for patience, again.  I've had a lot of orders that's backed me up from finishing the DoodleBug kits.  Hopefully, this weekend.


----------



## JacobLee89

avro_arrow said:


> A quick search provided the answer.
> 
> Yeti - Full Speed
> Yeti Pro - High Speed.
> ...


 
  
 Thanks! That's pretty good news, and I'll let you guys know if it makes any audible improvement.
  
 Out of curiosity, what did you search for to get the USB specs? I must have been typing the wrong keywords on the search engine..


----------



## Avro_Arrow

jacoblee89 said:


> Thanks! That's pretty good news, and I'll let you guys know if it makes any audible improvement.
> 
> 
> Out of curiosity, what did you search for to get the USB specs? I must have been typing the wrong keywords on the search engine..


 

 I just searched with "Blue Yeti USB Microphone".
  
 On Amazon, I found the it supports up to 16 bits at 48k and was "plug and play".
  
 That say to me "USB Full Speed device".


----------



## Architeuthis

Are there plans to make it available as a completed product or only as kits for DIY'ers?


----------



## tomb

architeuthis said:


> Are there plans to make it available as a completed product or only as kits for DIY'ers?


 

 It's a very simple build, but yes - I will build some for sale at some point.  The way things are going, though, that could be awhile.


----------



## kphfrail

Do we purchase this at beezar?


----------



## lordearl

kphfrail said:


> Do we purchase this at beezar?


 
  
 I think Tom said he was going to put it up on the site soon but still needed some time.
  
 Tom – are we able to start a list here of people who are ready to order it, so we get first priority of ordering?


----------



## tomb

lordearl said:


> kphfrail said:
> 
> 
> > Do we purchase this at beezar?
> ...


 

 It shouldn't be a problem.  I'm sure that there's plenty to go around for quite awhile.  I'm ready to pull the trigger and have all the kits made up, it's just that every time Mon-Thurs rolls around, I'm kind of limited by my day-job plus any regular Beezar business in-between.
  
 If you guys can be patient a few days longer, everything will be in place.  I know it's been a long time, but between moving to a new house, re-building Beezar with updated software basically from scratch, and any number of other things that happen to all of us in our daily lives, it's taken a lot longer than it should have.  Just a while longer and everything will be available on Beezar.com.


----------



## lordearl

Thanks Tom - you are a victim of your own excellent service!!  cheers mate.


----------



## JacobLee89

lordearl said:


> Thanks Tom - you are a victim of your own excellent service!!  cheers mate.


 
 I will second that sentiment!


----------



## skeptic

Tom is like the anti-Light Harmonics!  Fulfill existing obligations and orders first, release new products second, despite community demand.  Business ethics remain alive and well in Atlanta


----------



## head-hi

skeptic said:


> Tom is like the anti-Light Harmonics!  Fulfill existing obligations and orders first, release new products second, despite community demand.  Business ethics remain alive and well in Atlanta


 

 Pretty funny. True, also. I like Bottlehead's model better than LH's.


----------



## tomb

DoodleBugs have now infested Beezar.


----------



## Avro_Arrow

Yah!


----------



## 00940

Congrats


----------



## UKToecutter

I've ordered mine


----------



## Avro_Arrow

I bet Tom will be really busy for the next few weeks...sorry Tom...


----------



## DingoSmuggler

tomb said:


> DoodleBugs have now infested Beezar.


 
 Let me help you with that infestation...
 Just ordered a couple of doodlebugs and a pair of E90CC for the torpedo, and some other goodies too.


----------



## lordearl

yep ordered mine too.  The race to build is on.....first one to complete it has to give the most comprehensive review......


----------



## bada bing

I ordered 1 as well.
 A nice option would be to offer the complete kit without the enclosure, like how the PuP was offered.
 I can see building several of these to integrate into one case with a PuP or O2/Odac. I'd be a
 buyer of a couple more without cases.
  
 Thanks for another great, ready to build project.


----------



## tomb

Quote:


bada bing said:


> I ordered 1 as well.
> A nice option would be to offer the complete kit without the enclosure, like how the PuP was offered.
> I can see building several of these to integrate into one case with a PuP or O2/Odac. I'd be a
> buyer of a couple more without cases.
> ...


 

 Thanks for the order and the kind comment!
  
 EDIT: Never mind about the rant - moment of weakness, I guess.


----------



## jtwrace

Where can the PCB's be ordered from?  I have an ODAC that I'd be curious to try with it.


----------



## UKToecutter

http://www.beezar.com/catalog/index.php?cPath=52&osCsid=d041c1537ee2c00adf22761f582cdcd3


----------



## jtwrace

uktoecutter said:


> http://www.beezar.com/catalog/index.php?cPath=52&osCsid=d041c1537ee2c00adf22761f582cdcd3


 
 Thanks!


----------



## scootsit

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)?


----------



## Avro_Arrow

scootsit said:


> 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.


----------



## tomb

avro_arrow said:


> scootsit said:
> 
> 
> > 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)?
> ...


 






 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

dingosmuggler said:


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


 

 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

avro_arrow said:


> 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

avro_arrow said:


> 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

beefy said:


> Long time no see for most of you folks!
> 
> 
> 
> ...


 

 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


----------



## Beefy

dingosmuggler said:


> jdslabs do an 8cm mini USB, if that's any help


 
  
 Egad, that is ridiculous on the other end of the spectrum. Still, dirt cheap, so may be an option.
  
  


> Hey beefy, happy Australia day mate


 
  
 Heya Dingo! Australia, f'yeah! If you don't love it, leave! Oh wait......


----------



## mcandmar

tomb said:


> 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.


 
  
 1.5 feet is the perfect length for me, i use these from my isolators to DAC's.  The larger 24 gauge power wiring is what initially caught my interest, they also include a ferrite and gold plated connectors for a couple of $$'s, what more could you want 
	

	
	
		
		

		
			




  
http://www.monoprice.com/Product?c_id=103&cp_id=10303&cs_id=1030302&p_id=5446&seq=1&format=2


----------



## tomb

That one looks pretty good.  However, I have some questions:
  
 1. What is meant by "28/24AWG?"
 2. Would you guys prefer white or black?
 3. I've also found some black ones that just say they're 28AWG, but they're only 1 foot long.
  
 Is the ferrite core important in this application since the DoodleBug performs complete isolation?


----------



## mcandmar

tomb said:


> That one looks pretty good.  However, I have some questions:
> 
> 1. What is meant by "28/24AWG?"
> 2. Would you guys prefer white or black?
> ...


 
  
 1) 28AWG wiring for the two data lines, and heavier 24AWG wiring for the two power lines.  Same format as the Belken cable i also use, e.g.
  

  
 2) Black or people will think its made by Apple 
	

	
	
		
		

		
		
	


	



  
 3) Ferrite probably does nothing, but cant do any harm IMO.


----------



## pjoliver182

Hey guys. Is this an appropriate place to post troubleshooting questions about my recent doodlebug build?

I can't get my computer or my phone to detect my ODAC through it. I previously used my Note 4 through an OTG cable straight in to the ODAC.

the psu section seems fine and I've tuned the voltage between 5-5.25V in various tests. I can pick up 5.1V coming from my phone to the main chip.

When I plug the mini usb cable in I get continuity between R2 and R3 through the chip. the 6 pins connected to C3 and C8 give 3.36V relative to their respective grounds. I don't read any DC at R2 or R3 but I get about 4V at R5 and 3.6V at R4...They're supposed to be data lines though..


----------



## tomb

pjoliver182 said:


> Hey guys. Is this an appropriate place to post troubleshooting questions about my recent doodlebug build?
> 
> I can't get my computer or my phone to detect my ODAC through it. I previously used my Note 4 through an OTG cable straight in to the ODAC.
> 
> ...


 

 Pic?  We might be able to spot something obvious.


----------



## pjoliver182




----------



## pjoliver182

the soldering isn't as neat as I'd have liked


----------



## tomb

pjoliver182 said:


> the soldering isn't as neat as I'd have liked


 
 That's OK - we bare all around here.  It's the price in asking for help. 
	

	
	
		
		

		
		
	


	



  
 The DoodleBug has tremendous ground planes, so it is difficult to solder some of the ground connections.  Still, I'd say your PCB would benefit from some re-flowing over the entire PCB.  Use some good flux to help the heat transfer.  Messiness from flux can be cleaned quite easily.  Messiness from solder can mean the project won't work.  It looks like you may not have the pin next to R2 soldered at all.  Photos can be deceiving, though.  I half expected that you may have soldered the ADuM chip in backwards, but everything looks OK from a parts standpoint.
  
 The ADuM chip could stand to have its pins rolled with the soldering iron - as described here in the 3rd and 4th paragraphs and pics on this webpage:
http://diyforums.org/Doodlebug/DoodleBugsolder.php .  Also, your photo doesn't show the pins from the mini-USB jack.  If those look similar, clean them up and give them a roll to finish off the pins.  Take the Wima capacitor out of there for the time being, if you have to.  The other chips and through parts - same thing - try to up the heat with more flux and get that solder smooth.  What you need is high temperature, but don't leave it on the joint too long.  If the solder doesn't melt right away, all you're doing is getting the ground planes hotter and you could burn the PCB.  This may be difficult on the pins connected to the ground plane, but there's no reason not to get all the other joints looking smooth and liquid-ey.
  
 Finish up with some 90%+ alcohol to clean off the flux you use.  Let us know if you need recommendations on good flux and solder.  Again, this is described on the DoodleBug website at the same page mentioned above.


----------



## pjoliver182

I bought a 1mm tip especially but my solder is probably too thick. I don't have a flux pen either. I did find it difficult to solder ground connections even with my iron on full heat


----------



## JacobLee89

pjoliver182 said:


> I bought a 1mm tip especially but my solder is probably too thick. I don't have a flux pen either. I did find it difficult to solder ground connections even with my iron on full heat


 
  
 You'd probably want a thicker tip for better heat transfer. Most soldering is done without sticking the solder directly onto the soldering iron, but heating the part and letting the solder flow into the direction of the heat. Took me a lot of amateurish attempts to understand that concept of fluid dynamics.
  
 Flux also helps the solder to flow better, and it has made soldering so much easier.


----------



## Avro_Arrow

My two cents...

  
 Heat the board, not the component.
 I just use a Weller WES51 with a standard tip at 550 to 600 degrees.

  
 Another thing I noticed was that if you are using a device for the first time
 or have just reloaded your computer, you may need to directly connect your
 device to the computer before it will be recognized. Subsequently, it will
 work properly through the Doodlebug.


----------



## tomb

Any one else built a DoodleBug?  Have experiences to share?  Pics to post?


----------



## shake

tomb said:


> Any one else built a DoodleBug?  Have experiences to share?  Pics to post?


 
 I'm looking at building one.  I have a triad 12v unregulated wallwart.  Will it be safe to use?


----------



## tomb

shake said:


> tomb said:
> 
> 
> > Any one else built a DoodleBug?  Have experiences to share?  Pics to post?
> ...


 
  
 If that's 12V DC, then yes.  If 12V AC, then it may be too much.


----------



## shake

tomb said:


> 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.


tomb said:


> If that's 12V DC, then yes.  If 12V AC, then it may be too much.


 
 Thanks for the info.


----------



## tomb

shake said:


> tomb said:
> 
> 
> > Is the ferrite core important in this application since the DoodleBug performs complete isolation?
> ...


 
  
 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.


----------



## Planar_head

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.


----------



## dBel84

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


----------



## tomb

dbel84 said:


> 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.
> 
> ...


 
  
 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.


----------



## dBel84

Thanks will give this a go when I get back to the office.


----------



## mcandmar

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.


----------



## lordearl

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!!


----------



## tomb

lordearl said:


> 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.
> 
> ...


 
  
 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.


----------



## lordearl

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.


----------



## tomb

lordearl said:


> 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
> ...


 
  
 Cool!  Thanks for the great comments on your experience with the DoodleBug!


----------



## dudetato

When do you think this will be available to buy?


----------



## tomb

dudetato said:


> 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. 
	

	
	
		
		

		
		
	


	




 
  
  
 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.


----------



## dudetato

I already saw your kit for sale, but I wanted to know when it would be available as a fully completed product


----------



## Gijs

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


----------



## tomb

gijs said:


> 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.
> 
> ...


 
  
 You're perfect! 
	

	
	
		
		

		
			





  5.25VDC is exactly what's needed to ensure that all the numerous regulators on the PupDAC have sufficient "headroom" to maintain regulation.
  
 Many thanks for the kind comments and congrats on your listening!  The PupDAC with the DoodleBug (set to 5.25VDC) is my primary source.  It sounds glorious with the Torpedo III.  I may be shilling, but that's my end game so far.  I am now trying my best to figure out how to finance a pair of HD800's.


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## Gijs

Thanks Tom! I hadn't checked these forums for a while and completely missed the arrival of the Torpedo III. You're not the only one with financial dilemma's now... For now, I will have to make do with the Torpedo I with a pair of Philips tubes. Oh well... But, joking aside, the Doodlebug is a massive upgrade to my little system! Keep up the good work!


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## hembergler

Another happy builder here--finished up a Doodlebug and pupDAC from Tom's immaculate kits and added them to my work setup. Sounds wonderful... a bit too good for being at work 
	

	
	
		
		

		
		
	


	



  
 The ground plane on the Doodlebug was a little bit more challenging than I expected, I don't think I've ever had to turn my iron up as high as I did for that. All in all a lot of fun to build and great to listen to. Thanks tomb/Avro!


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## 39points

Looks interesting


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## tomb

hembergler said:


> Another happy builder here--finished up a Doodlebug and pupDAC from Tom's immaculate kits and added them to my work setup. Sounds wonderful... a bit too good for being at work
> 
> 
> 
> ...


 

 Yep - those are massive ground planes on the DoodleBug, but it contributes to the low noise of the power supply.
  
 Thank you for the wonderful comments!


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## nikobi

Hi,
  
 Trying to test my doodlebug, as I suspect something is wrong.
 Unfortunately I have only one computer with USB 3 connectors only and an unsoldered as-of-yet pup-dac kit.
  
 My doodlebug looks OK, both LEDs light up (12V dc power dupply), voltage between test points is 5.25v but I cannot make it work.
 Is it ok to use a USB mouse or keyboard to test the doodlebug?
 When I connect a spare usb mouse, the mouse led does not light up and no connection is made.
 I tried to use it with my only other usb component, a musical fidelity V-dac II, but that did not work either, but that might be a high-speed device.
 Any input is welcome,
  
 Nik


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## Avro_Arrow

The Doodlebug does nothing on it's own, that is, it is not recognized as
 a device by the computer. It is locked at USB full speed and will not
 work with devices at USB low speed or USB high speed.
 If you have a mouse that runs at USB full speed, it should work, but
 I think most mice are USB low speed devices.
 The 5.25 volts shows the power supply is working properly.
 New devices (ones that have not been connected to your computer
 before), may need to be plugged in on their own and be recognized
 by the computer before being used through the Doodlebug.
  
 In short, there is nothing to indicate you have a problem.
 Get your pupDAC up and running then you can test the Doodlebug.
  
 Cheers!


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## nikobi

OK, thanks for the heads-up Avro_Arrow - I'll finish my pupDAC and report back. This is probably going to take a week or two, though.
 Cheers,
 Nik


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## nikobi

OK, so I've finished my pupDac now. Unfortunately something does not seem to work.
 When I connect the pupDac to my Ipad (via connection kit), Ipad shows a message along the lines of: "Device not available. Connected device is using too much current".
 Then, when I connect the Doodlebug nothing happens.
 Doodlebugs two LEDs light up, pupDacs LED does not. Dac is not recognized (no error message, Ipad plays music through internal speaker).
  
 Now, unfortunately, my Ipad is my only non-USB3 device. Makes it hard to try things.
  
 What I noticed:
 I do not trust the small mini-usb jack (computer side). The plug does not go in very far and it does not give a locking sensation like the one from the pupdac does.
 The Voltage regulator gets really warm, but then that might be just a part of its job?
 Any ideas what I can try?
 Cheers,
  
 Nik


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## ericj

Just noticed this thread. 
  
 I would like to have a USB isolator but not for audio purposes. 
  
 Does this provide full galvanic isolation of the USB device? By that i mean, does it break all DC paths between the host computer and the USB device? 
  
 A year or so back i let the magic smoke out of a $350 diagnostic interface (Rosstech HEX+CAN) and had to pay $150 for out of warranty repair -- because i had the laptop powered by the car when i connected the interface to the OBDII port. 
  
 Somehow even though the ground at the laptop's dc power supply was at the same potential as the car's ground, ground at the usb port was far enough different that i cooked the diagnostic interface.


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## Avro_Arrow

ericj said:


> Just noticed this thread.
> 
> 
> 
> ...


 

 Yes, it provides complete galvanic isolation. Just make sure your device works at USB full speed, not low speed or high speed.
  
 Edit: I think your interface may be a low speed device. Contact the manufacturer to make sure.
 The Doodlebug can be hacked to run at USB low speed.


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## Avro_Arrow

nikobi said:


> OK, so I've finished my pupDac now. Unfortunately something does not seem to work.
> When I connect the pupDac to my Ipad (via connection kit), Ipad shows a message along the lines of: "Device not available. Connected device is using too much current".
> Then, when I connect the Doodlebug nothing happens.
> Doodlebugs two LEDs light up, pupDacs LED does not. Dac is not recognized (no error message, Ipad plays music through internal speaker).
> ...


 

 USB 3 ports are backward compatible with USB 2
 Sounds like you have a short in your pupDAC
 The voltage regulator usually gets only mildly warm, not much above room temperature
 in normal use. The Doodlebug can protect itself from shorts with an auto reset fuse.
 Go over all the solder joints and look for any bridges.


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## ericj

avro_arrow said:


> Yes, it provides complete galvanic isolation. Just make sure your device works at USB full speed, not low speed or high speed.
> 
> Edit: I think your interface may be a low speed device. Contact the manufacturer to make sure.
> The Doodlebug can be hacked to run at USB low speed.


 
  
 Pretty sure i can just ask the usb stack.
  
 Good to know. I may build one of these. 
  
 Can't tell you how annoyed i was to discover that a $350 diagnostic cable isn't isolated.


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## mcandmar

ericj said:


> A year or so back i let the magic smoke out of a $350 diagnostic interface (Rosstech HEX+CAN) and had to pay $150 for out of warranty repair -- because i had the laptop powered by the car when i connected the interface to the OBDII port.


 
  
 Don't like the sound of that, how were you powering your laptop?   I use mine with a cheap DC-AC inverter powering the stock laptop power supply and never had a problem, but you have me worried now...


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## ericj

mcandmar said:


> Don't like the sound of that, how were you powering your laptop?   I use mine with a cheap DC-AC inverter powering the stock laptop power supply and never had a problem, but you have me worried now...


 
  
 A cheap inverter might be the safer way to do it, depending on the inverter. A lot of them do use a transformer.
  
 I was using a Power+ brand DC-DC power supply that was made specifically for the laptop. 
  
 Ross-tech says to check for current between the ground on the usb shell and the ground of the car. They also think this only happens with "cheap, generic, universal" adapters.


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## Rossymusic4

I am having a problem getting my Doodlebug to work. I recently bought it from a friend of mine along with his amp, dac and M2tech Hiface. The system worked beautifully together at his place but now, plugged in to my own computer's USB 2, there is no sound even though music appears to be playing on my Jriver. The PCs recognizes the the converter through the Doodlebug. When I remove the Doodlebug and plug the M2 tech Hiface directly into the USB port there is no problem. I have tried all the ports and have steamed rebook and hi res files from this computer for 2yrs. I suspect it must be high speed which would make it incompatable. Is there a hub I can use to make it full speed ?
Any other suggestions?


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## Avro_Arrow

What sample rate and bit depth are you using? The Doodlebug is a black and white kind of device.
 Either it works perfectly or it doesn't work at all.
 The Doodlebug can only support USB full speed operation. High speed is not supported.
 Due to the complexity of the USB High Speed signal, there is no isolator that can handle it.
 Your friend might be able to help you find settings that work with your setup.
 My own setup uses a pupDAC which is a USB Full Speed device.
 I have my Foobar2000 set to 24 bits at 48k. In theory, USB Full Speed should
 be able to do 24 bits at 96k.


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## Rossymusic4

I'm using standard redbook 16/44k in Jriver. What other settings should I be looking at? Does the player software make any difference?


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## Avro_Arrow

The player software should make no difference. I use both JetAudio and Foobar2000
 without any problem.
  
 The Hiface is a USB High Speed device, I suspect that is where the problem lies.
 Again, your friend was able to get them to work together, ask them how they had
 it set up.
 Are you using the M2Tech drivers? Was your friend using the drivers?


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## FallenAngel

avro_arrow said:


> The player software should make no difference. I use both JetAudio and Foobar2000
> without any problem.
> 
> The Hiface is a USB High Speed device, I suspect that is where the problem lies.
> ...


 
  
 It was plug-and-play for me with the Doodlebug and M2Tech HiFace. I just had to be sure to plug in the Doodlebug power first and the rest was without issue.
  
 HiFace version 1 requires drivers. I installed those, got it working without the Doodlebug and then just plugged it in between without issue.
  
 Of my thousands of albums, they are almost all CD rips to FLAC or MP3, but I'm not sure if that matters.


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