[doobooloo]

I'm trying to put together guzzler's USB DAC:

http://www.mellowparenting.demon.co....er/usbdac.html

I have obtained all parts except the tiny WIMA box caps. They're 100nF 2.5mm pitch 3mm width parts, and I need 16 of them as I have two USB DACs that I'm putting together. However, I can't seem to find a distributor for those caps - in fact, I can't seem to find any US distributor that carries suitable replacement PCM2.5 caps.

I think they're more readily available in Europe...

Anyway, does anyone know where I can purchase these caps? Or, does someone have a few (at least 16, actually) that they are willing to sell to me? Worst comes to worst, if they're available in Europe or elsewhere would someone be generous enough to purchase them and ship them to me?

I hope I can somehow get these caps soon...

Thanks in advance for your help!

 

[Whit]

You can get them at Mouser.

http://www.mouser.com/index.cfm?hand..._pcodeid=50501

 

[doobooloo]

Wow, thanks a lot Whit!

I never knew Mouser had these in stock. Their catalog only showed the larger caps so...

 

[nleahcim]

Quote:

Originally Posted by Whit You can get them at Mouser. http://www.mouser.com/index.cfm?hand..._pcodeid=50501

I'm working on putting together the same usb dac - and I saw those too - but was worried that they're 100V... Are they still the same form factor and everything?

Also - doobooloo - what parts are you using for the two inductors?

Similarly - what about the 3 tantalums? (1x47uF and 2x10uF)

And the two NP0 ceramics?

Lastly what about the black gates and os cons?


I'm having the damndest time trying to get all these parts collected... I really wish more standard parts had been used...

 

[doobooloo]

I have the rev.A so if you have the beta version, some parts may differ.

Inductor: 580-17103 from Mouser ($1.19 each)
47uF Tant: 74-199D6.3V47 from Mouser ($0.79 each)
10uF Tant: 399-1379-ND from Digi-Key ($0.59 each)
Ceramic: 399-1892-ND from Digi-Key ($0.28 each)
Black Gate: 3-11410 100uF/6.3V NX from Handmade ($6.95 each)
OS-CON: P11167-ND from Digi-Key ($0.39 each)
WIMA: 505-MKS2.22/50/10 from Mouser ($0.31 each)

Although I ordered some from Digi-Key and some from Mouser, you should be able to get all from Mouser other than the Panasonic FC caps. I had to order a bunch of other stuff from both distributors anyway, so it didn't really make a difference for me.

The Black Gates are 100uF but this should be better.
I am just using the Panasonic FCs in place of OS-CONs, they shouldn't make that big a difference. Also note that I am using the largest possible value for all the electrolytics (problem if you're using a thin case).

I also went with 0.22uF WIMA MKS-2s instead of 0.1uF because they didn't have 0.1uF in stock and looking at the schematic most were just rail caps anyway (if I understood correctly) aiding the slower electrolytics, so I just got the largest in-stock possible for the size which was 0.22uF.

Also, I only see one inductor... what do you mean by two inductors?

Hope this helps! I'm so excited to finally get this built!

 

[nleahcim]

Quote:

Originally Posted by doobooloo I have the rev.A so if you have the beta version, some parts may differ. Inductor: 580-17103 from Mouser ($1.19 each) 47uF Tant: 74-199D6.3V47 from Mouser ($0.79 each) 10uF Tant: 399-1379-ND from Digi-Key ($0.59 each) Ceramic: 399-1892-ND from Digi-Key ($0.28 each) Black Gate: 3-11410 100uF/6.3V NX from Handmade ($6.95 each) OS-CON: P11167-ND from Digi-Key ($0.39 each) WIMA: 505-MKS2.22/50/10 from Mouser ($0.31 each) Although I ordered some from Digi-Key and some from Mouser, you should be able to get all from Mouser other than the Panasonic FC caps. I had to order a bunch of other stuff from both distributors anyway, so it didn't really make a difference for me. The Black Gates are 100uF but this should be better. I am just using the Panasonic FCs in place of OS-CONs, they shouldn't make that big a difference. Also note that I am using the largest possible value for all the electrolytics (problem if you're using a thin case). I also went with 0.22uF WIMA MKS-2s instead of 0.1uF because they didn't have 0.1uF in stock and looking at the schematic most were just rail caps anyway (if I understood correctly) aiding the slower electrolytics, so I just got the largest in-stock possible for the size which was 0.22uF. Also, I only see one inductor... what do you mean by two inductors? Hope this helps! I'm so excited to finally get this built!

Yes - that definitely helps!

Oh, the extra inductor is mentioned in Guzzler's revision A notes here: http://www.mellowparenting.demon.co....er/usbdac.html - it goes from R7 (USB VCC) to the + input. As far as I know it's only beneficial if you're using the USB power supply (as opposed to batteries or an external power source) - but as I plan on using the USB power supply - I'm definitely adding it! Oh and yup - I'm also using two of the newer boards.

Oh and don't worry - I have no problems ordering through multiple distributors. I order through my university, and not only do we get free shipping, but we also get a discount! (as long as it's a major distributor)

Wow - $7 for each blackgate - that's quite alot! I was thinking I'd try to order from Percy Audio - they have the Nx HIQ 47µF 6.3V for $2.50 each (page 7: http://www.percyaudio.com/Catalog.pdf)

Uh oh - I just noticed that percyaudio has a minimum $25 order and standard $6.50 shipping

. So the price difference would be fairly minimum. Maybe a group of us could order up 10 or so? (if you and I went in on it alone that'd be 8 - if you'd be interested, and if you haven't already ordered) I'd be willing to handle shipping them out to everybody else - or somebody else could - makes no difference to me. (I'm not in much of a rush - as I haven't even received the PCBs yet...)

About the Wimas - so using a larger cap won't affect sound quality? Or it will just be a negligible effect? Or will it actually improve it?

Lastly - regarding your replacement of the os-cons, those panasonics are fairly large - 1.5cm tall if I'm reading the datasheet correctly - for one of the boards it wouldn't be a problem - but for the other it might (it'd definitely be close, that's for sure). Do you think such a large capacitor is really necessary? I mean Guzzler's design called for 47uF caps...

Anyways - thanks for the info - that's definitely helped out a lot!

 

[guzzler]

Only the crystal load capacitors (32pF ceramics), and the two 10uF tantalums in the switching part of the power supply are really important in terms of value and type. The output capacitors I've specced as Black Gates don't have to be that, just that is the best available that will populate that space. Similarly, the OS-CONs can be replaced with Panny FCs with no real impact, it's just OS-CONs were easier and cheaper to get here than the FCs and my list specs the best possible combination of components. As doo said, the WIMAs can be the .22uF versions without any problems. The sizes are mentioned on the web page, so just stay within the limits and you'll be fine. All the parts I spec can be substituted by "standard" components, but since it was going to be fairly cheap anyway, I thought we'd go with the cost-no-element type idea. The original kit sold for $30-35 minus semiconductors, so total for the board was only around $50 or so.

Regards the LCR filter for USB power, I think I should clarify:

If you would like to run off batteries, all you need to do is jumper over the 1206 style resistor on the top left and that is you.

For USB power, get a 10uH axial inductor as well as the 10uH radial inductor. Run the axial inductor from a pad on R7 to V+. There is a 10R resistor in all the bags, use this to populate the top left 1206 resistor position. The 47uF tantalum I recommend therefore sets the corner frequency of the low pass filter these three components (inductor, 10R resistor, xx uF tantalum) form. The bigger the tantalum you can get to fit in that position, the more of the high frequency junk you can filter out. Remember, tantalums are polarised and do have a working voltage specified. IIRC, the 47uF I spec sets the corner frequency at 15kHz. The equation to calculate is f=1/2(pi)*R*C.

I hope that helped everyone, and I apologise for having been retiscent in updating the page as I've just started university, and things have been very hectic but as always don't hesitate to get in touch with me regards any matter... I really do hope you enjoy building and listening to these, and it's certainly a step up for the soldering skills

regards

g

 

[Pars]

Kyoto-Electro has the Black Gates for $4.60, but appears not to have them in stock currently. You might check with them however if you need very many of them (www.kyoto-electro.com).

 

[Pars]

Oh and one other thing regarding Wimas here in the US. Mouser does carry them (some), but has rather large minimum orders on many of them (50-100 or more).

Check with TAW electronics (www.tawelectronics.com). They sell small quantities (each), and while you can't do a web order like mouser, they will do orders via email or phone, and have good pricing to boot. They also return your email promptly (same day).

I am about to place an order with them for some 4.7uf that Mouser had a 50 min order for.

Chris

 

[doobooloo]

Actually, I just cancelled the order for four 100uF 6.3V NX blackgates from Handmade to order eight 47uF 6.3V NX Hi-Q blackgates from kyoto-electro. Not only is this cheaper, but with four blackgates per dac, I can pair them in "Super-E" configuration:

In case one isn't familiar with the concept, here is what the blackgate website says:

What is the "Super-E-Caps"?

A pair of nonpolarized Black Gate electrolytic capacitors are particularly connected in parallel or in series so that each one of the capacitors cancels the internal magnetic flux generated by the other, thereby completely eliminating internal resonance and decreasing total impedance to absolute zero as the frequency increase.

Hopefully this will further lower distortion and any other negative side effects of having electrolytic capacitors in the signal path.