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Alien DAC v1.1 Construction Thread - Page 2

post #16 of 1560
7/13/06 at 6:28pm
Quote:
Originally Posted by Alf
I just realised that I have never published my BOM

Here it goes.
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post #17 of 1560
7/14/06 at 3:04am

i think the boards are strange

hello,

by inspection, my boards look like the pads are covered by the silkscreen material.

is this normal?
here is a scan of the board:




i scratched some silkscreen material off to reveal the pad underneath.

[NEVERMIND]
a quick 5 second test with a soldering iron answered all my questions. I never seen this pad coating before... the boards i get usually have tinned pads that are shiny.
Look forward to building this thing after my MCATs.

thanks,
fred
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post #18 of 1560
7/14/06 at 4:28am

R31 on the top ?

From Assembly page :

Quote:
If you use an adjustable regulator IC3, populate the C32 position on the bottom side while R31 and R32 go to the top side.
There does not seem to be a place on the top for R31 (well at least to my eyes right now). Should R31 actually go on the bottom (top is where the PCM chip is right ?)
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post #19 of 1560
7/14/06 at 8:46am
My digikey BOM is attached. Please double check things though

(Also - would any americans/canadians that are doing a digikey order soonish please check out this thread, it would be really appreciated )

Rob.
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post #20 of 1560
7/14/06 at 3:39pm
Quote:
Originally Posted by frdchang
hello,

by inspection, my boards look like the pads are covered by the silkscreen material.

is this normal?

....................

a quick 5 second test with a soldering iron answered all my questions. I never seen this pad coating before... the boards i get usually have tinned pads that are shiny.
Look forward to building this thing after my MCATs.

thanks,
fred
EuroCircuits use "immersion silver" technology. I think you have been scratching off the silver coating.
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post #21 of 1560
7/14/06 at 4:09pm
Quote:
Originally Posted by cook
From Assembly page :



There does not seem to be a place on the top for R31 (well at least to my eyes right now). Should R31 actually go on the bottom (top is where the PCM chip is right ?)
Well spotted. Thanks for bringing it up. Your assumption is correct. It should say

"If you use an adjustable regulator IC3, populate the C32 and R31 positions on the bottom side and R32 on the top side."

I updated the web site accordingly.

Quote:
Originally Posted by cook
top is where the PCM chip is right?
Correct
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post #22 of 1560
7/15/06 at 1:36am
So it works just fine Sound is fine. I didn't have much time to compare it to my Revo 5.1 though.

Still have to play with regulator - may have to decrease R31/R32 to let regulator kick in. Right now regulated 5V it almost same as it comes from USB.

I checked DC offset without CL/CR and it was more than 1V. Right now I'm waiting for Blackgates and have temporary CL/CR in the DAC. I'm wondering why DC offset with CL/CR but without amp connected was still high. Now it's in mV range with amp connected and CL/CR... Haven't had time to check what if I remove CL/CR and connect amp. May be I can bypass CL/CR. If not - I'll need a lot of patience to wait when/if www.kyoto-electro.com shipment will come. It's already 2+ weeks wait

After build it needs cleaning big time. I still have a bit of rosin under the chips. No way I can clean that. Here are pics for your pleasure :

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post #23 of 1560
7/15/06 at 8:50am
Gosh - I hope that's not a bad sign - I ordered BG's from kyoto-electro, too. I have been a little concerned since I received neither order confirmation or Paypal payment confirmation from them.

EDIT: Nice pics, BTW.
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post #24 of 1560
7/15/06 at 10:18pm
Well something not right with my IC3 REG101UA-5. I have 5.3V from USB and 5.2V after reg. No matter how much I decrease R31/R32. Even after adding 22k parallel to the R31. Are those REG101s easily damaged ?


Re: kyoto-electro: I've got Paypal/order confirmation on 6/23 but still no reply whether they shipped it or not...
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post #25 of 1560
7/15/06 at 10:31pm
Quote:
Originally Posted by tomb
Gosh - I hope that's not a bad sign - I ordered BG's from kyoto-electro, too. I have been a little concerned since I received neither order confirmation or Paypal payment confirmation from them.

EDIT: Nice pics, BTW.

After three weeks and 4 emails I got sick of waiting for them to even reply to my emails and filed a claim with Paypal.
They did not even respond to the emails Paypal sent them about the claim and as such it didn't take Paypal very long to "settle the dispute"

parts conneXion here you come.
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post #26 of 1560
7/16/06 at 1:52am
Thread Starter 
IMHO, partsConnexion is the best source I would go for. It does take them 1 or 2 days to process your order, but it is because they are careful. I once ordered some PRP resistors, and it was the the .5watts that I am ordering. I put the part number as the 1watts ones, and wrote the description as .5watts. They called me a day after I sent in the order, to confirm about the order. I really like that, and they even changed my shipping method from express post (what I picked) to UPS, because they found it to be cheaper. It came in within 3 days. Very nice.

Peter
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post #27 of 1560
7/16/06 at 5:08am
Quote:
Originally Posted by cook
Well something not right with my IC3 REG101UA-5. I have 5.3V from USB and 5.2V after reg. No matter how much I decrease R31/R32. Even after adding 22k parallel to the R31. Are those REG101s easily damaged
Do you use the adjustable version of REG101 or the 5V one?
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post #28 of 1560
7/16/06 at 5:40am
Quote:
Originally Posted by Alf
Do you use the adjustable version of REG101 or the 5V one?
Doh! I didn't realize they are different. I'll have to order REG101UA-A one.
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post #29 of 1560
7/16/06 at 7:57pm
Quote:
Originally Posted by MisterX
After three weeks and 4 emails I got sick of waiting for them to even reply to my emails and filed a claim with Paypal.
They did not even respond to the emails Paypal sent them about the claim and as such it didn't take Paypal very long to "settle the dispute"

parts conneXion here you come.
Drat! I was afraid of that.

P.S. I ordered the REG101UA-5, too. Better check those BOM's on the Group Buy thread. The last 3 BOM's were meant for a regulated, USB-powered config, and everyone of them had REG101UA-5.
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post #30 of 1560
7/17/06 at 12:14am
Thread Starter 
I am a little confused about IC3. I thought we can't really use the fixed voltage regulator, REG101UA-5, REG102UA-5, for direct USB powered option. The part list note says that, it doesn't really regulate. Instead we have to use REG101UA-A, or REG102UA-A as adjustable regulator, and regulate it down to 4.8V using R31 and R32. But at the same time, the part list tells that they are only mandatory for all configurations except Direct USB. What is right? I am planning to use the DAC always USB powered, what should I get?

Thanks,
Peter
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