Alien DAC v1.1 Construction Thread
Jul 12, 2006 at 3:13 AM Thread Starter Post #1 of 1,562

peterpan188

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Since most people are getting the PCBs in the comming week, I will just start this off.

Does anymore have a complete BOM for USB power option, regardless from Digikey or Mouser?

Also, for CL and CR, I assume film caps are the choice there rit?

Thanks for Alf, for all this effort.

Thanks,
Peter
 
Jul 12, 2006 at 10:55 AM Post #4 of 1,562
My shopping list at Farnell, should it interest anyone. I make no promises as to whether this list is complete or not, or made of the best components available - I've gone for good specifications, good price, and a few different types of capacitor for CL/CR - Sanyo SH should sound nice from what I've read, if you don't fancy trying the tantalums or whatnot.

Apparantly, Naim only bother with tantalums for coupling. Wonder if it's one of the reasons for their uncoloured sound?

Code:

Code:
[left]QtyP/NDescPri(ea) ----------------------------------------------------------- 1x418596Soldering tip£2.31 // Probably only 1x418560Soldering tip£2.31 // applicable to 1x1182013Desolder braid£1.09 // me ;) ----------------------------------------------------------- 8x3056594Ferrite 600R£0.22 1x95277020805 2.2UF 25V£0.037 1x8812381CAPACITOR, 470UF 10V£0.26 2x7552290805 33PF 50V£0.028 1x4310007CAPACITOR, 47UF 6.3V£0.65 10x75695640805 S/TERM. 100NF 50V£0.057 *********************************************************** /////////////////////////////////////////////////////////// 2x1144596CAPACITOR, 100UF 6.3V£0.128 Out of stock. Alternative below. /////////////////////////////////////////////////////////// 2x9452354CAPACITOR, 100UF 6.3V£0.164 *********************************************************** 2x1100453TANTALUM 22UF 6.3V£0.44 // Experimentation with CL/CR 2x1166632ALUM. ELEC. 10UF 25V£0.69 // Experimentation with CL/CR 2x9189440SANYO SH, 4.7UF 25V£0.62 // Experimentation with CL/CR 2x9527710CAPACITOR 0808 1UF 16V£0.033 // Experimentation with CL/CR 2x9527699CAPACITOR 0603 1UF 6.3V£0.023 // Experimentation with CL/CR 2x9332847RESISTOR, 0805 22R£0.02 1x9332600RESISTOR, 0805 1K5£0.02 1x9332413RESISTOR, 0805 1M£0.02 1x9333070RESISTOR, 0805 330K£0.02 2x9334310RESISTOR, 0805 620R£0.02 1x971276312mhz 20ppm£1.18 1x971295012mhz 30ppm£0.72 1x10032093mm LED£0.09 1x1097897USB type B£1.12[/left]

I did try to get away with a cheaper USB socket, but couldn't find one with the same pin-out. Meh...

I've got 4 boards here, and will be doubling up on many of the above values. PRICES ARE PER INDIVIDUAL ITEM, NOT FOR THE QUANTITY REQUIRED.

Hope I've not missed anything
frown.gif
.

--Rich
 
Jul 12, 2006 at 11:27 AM Post #6 of 1,562
I tried using all of the various BOM's available, but Doobooloo's spread between DigiKey and Mouser was best. However, she didn't choose to go for the Regulator at 4.8V with R31/R32. So, you may want to add those three things. Hers is here: Doobooloo's Alien DAC BOM

Cook wrote one up for quantity X 2, which was helpful for me, but DigiKey is out of stock on some items - like the USB socket. His BOM appears to be an HTML-version of the DigiKey order printout, so it will not be as flexible: Cook's BOM

Note that Doobooloo's USB socket has gold-plated contacts (Mouser). That may not be obvious if you try to source one somewhere else. She also included an Xtal Mylar spacer, which may or may not be important, but is a pretty cheap thing to add just in case.

Finally, keep your eyes open on the SMD stuff. It hardly makes sense to order 2 or 3 SMD resistors when 10 are cheaper.
wink.gif
 
Jul 12, 2006 at 12:00 PM Post #7 of 1,562
Quote:

Originally Posted by RichA
I've gone for good specifications, good price, and a few different types of capacitor for CL/CR - Sanyo SH should sound nice from what I've read, if you don't fancy trying the tantalums or whatnot.

Apparantly, Naim only bother with tantalums for coupling. Wonder if it's one of the reasons for their uncoloured sound?



standard tantalums are known to be bad when used in the signal path, I'd rather try a boxed polyester cap (like Wima MKS) when the cap has to fit onto the pcb or a (metallized) polypropylene film cap (like Wima MKP) when the cap can be air wired between pcb and rca jacks
 
Jul 12, 2006 at 9:14 PM Post #8 of 1,562
Ah well, got enough bits to let me fiddle
smily_headphones1.gif
. I'll have one reference design, and one for tweaking
smily_headphones1.gif
.

--Rich
 
Jul 13, 2006 at 2:45 AM Post #9 of 1,562
I am looking over again at the Alien DAC part list page. It recommands electrolytic for CL and CR. From my understanding, is it bad to use such in a signal path directly? Isn't film types (Musicap, Wima MKP10, Cardas caps, Pany ECQ-P) better in this application?

Thanks,
Peter
 
Jul 13, 2006 at 5:55 AM Post #10 of 1,562
After reading dsavitsk's reviews on capacitors (referenced in Alf's Parts List discussion on CL/R), it seems apparent that 47uF, 6.3V NX-HiQ Black Gates are the output caps of choice for DAC's. I have been afraid of Black Gates for obvious reasons, but the ones of this size are about $2.50 ea. That's a small price to pay to mean the difference between a juicy-sounding DAC and one that's only so-so. They will fit the board pattern perfectly, too.

Note that Doobooloo's BOM, that I referenced in the earlier post above, also has these Black Gates listed for CL and CR.
 
Jul 13, 2006 at 6:36 AM Post #13 of 1,562
The suppliers I've checked do not have NX-HiQ in 4.7uF. You have to go with 47uF to get the NX-HiQ, and that is still within the range that Alf specifies. Further, the less quality, 4.7uF is more expensive:

Kyoto-Electro

The Nichicon Muse ES is the same way - at least at Handmade Electronics. The smallest is the 47uF. They are listed at $0.32, but Handmade has a $12.99 minimum, and a surcharge up to $25. It's hard to tell, though - they are in the process of renovating their website and things are screwed up.
 

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