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Alien DAC v1.1 Construction Thread - Page 44

post #646 of 1562
Quote:
Originally Posted by GarlicKnots View Post
Both 27/28 are bridged. They both go to ground. I also bridged 13/14 since they go to ground. That is OK, I believe?
nope.

http://focus.ti.com/lit/ds/symlink/pcm2702.pdf

Pinout is on page 3

28 goes to the crystal.
27 is VccP

Its hard to tell from the photos but it looks like those might be bridged. If they are you could get that error message. If you have access to an oscilloscope you can check if the crystal is oscillating.

25 is VccL 24 is AGNDL -- Yeah if those were bridged, you wouldn't have a working +5V supply. My bad.
post #647 of 1562
Quote:
Originally Posted by GarlicKnots View Post
Q. If I'm getting 3.3 and 4.7, should I refrain from touching 2-9 and 16-26?

I was getting the right voltage on the regs but it was either pin 2 or 3 that was open and I had that exact same problem as you. In fact you should get the right voltages with or without the chip installed, so just because they're right, doesn't mean they're actually connected to the chip. Unless you mean you're measuring the voltage on each pin as what it should be, in which case there shouldn't be a need to do anything to those pins.
post #648 of 1562
Quote:
Originally Posted by AndrewFischer View Post
nope.

http://focus.ti.com/lit/ds/symlink/pcm2702.pdf

Pinout is on page 3

28 goes to the crystal.
27 is VccP

Its hard to tell from the photos but it looks like those might be bridged. If they are you could get that error message. If you have access to an oscilloscope you can check if the crystal is oscillating.

25 is VccL 24 is AGNDL -- Yeah if those were bridged, you wouldn't have a working +5V supply. My bad.
Andrew, you're correct, my number configuration was incorrect. I thought the pin across from pin 1 was pin 15, it's pin 28.

I'm bridging 13/14 and 15/16 by the correct pin out diagram. Those go to ground.

I did some more resoldering, etc.

I plugged it in and it actually recognized it at first as USB speaker, burr brown, etc.

The 3.3 rail was correct.

However the 5v rail was registering .1.

I unplugged, replugged and this time it didn't recognize.

More soldering, eh? Hopefully, I didn't burn the chip.

f/R
post #649 of 1562
I finally got around to populating two of my boards from the 2nd group buy today after free time suddently manifest. Both work great, though one malfunctioned due to some solder bridges on the 2702 and a mistake soldering the oscilator connections.

I'd like to case them up with some existing amplifiers now, but I don't have panel space to put the PCB against it.

Can someone please direct me to a panel mount usb jack?

---------
When I was debugging the 'bad' board, windows also gave me a malfunctioning usb device error. I suggest that you measure the voltage of the two pins at closest to the crystal. They should be about 1.5V each. If they are not, the the 2702 will not function properly because its clock is malfunctioning. R14/C11/C12 on the bottom side also need to be checked. This was how I figured out what the problem was - a bad solder joint on the bottom side of the board. I hope that this helps.
post #650 of 1562
Snoopy: Mouser part# 568-NAUSB-B Neutrik quality there, and they also have it in silver

And what BOM did you go by
post #651 of 1562
Another option for USB panel mounted receptacles is l-com

http://www.l-com.com/item.aspx?id=4758

They also sell pretty nice RCA jacks.
post #652 of 1562
You guys are great. I was wondering if anyone had tried remote mounting for the USB jack. Any noise problems or lead length issues?
post #653 of 1562

Alien DAC kits and boards are ready

Quote:
Originally Posted by error401 View Post
Ooops! So sorry Alf, I knew it was a 3-letter name starting with a, and yours came to mind.
Yes, I had boards made with Alf's help. They are now ready along with my kit.

BOM and email address can be seen here:

http://www.geocities.com/jeffrossel/

I will try to get in touch with all the people who contacted me, but if I miss you please Email me.
post #654 of 1562
Reading the list of parts I see at the bottom it has an option for bare boards, no price though. This a yet to be added option ?
post #655 of 1562
Quote:
Originally Posted by splaz View Post
Reading the list of parts I see at the bottom it has an option for bare boards, no price though. This a yet to be added option ?
The price for bare boards is 2.00 each (close to my cost), which is less than the previous group buy due to my not having to pay VAT.

JR
post #656 of 1562
Looks like a good BOM and a great price on the boards.
post #657 of 1562
[nvm first part]

The windows does not recognize this device errors--try checking continuity between the USB pins. One of my DACs had that shorted, and Windows couldn't ever detect it properly. I found out that the short was likely under the PCM2702 somewhere, and honestly I just gave up on that DAC. If you're lucky, your problem is somewhere obvious; otherwise, you've got quite a bit of desoldering to do =(
post #658 of 1562
Quote:
Originally Posted by dakotart1984 View Post
Snoopy: Mouser part# 568-NAUSB-B Neutrik quality there, and they also have it in silver

And what BOM did you go by
On order.

I used this one (see attached). There are a few items not listed because I already had them (usb jacks & output DC blocking caps).

------------------------------
I found another panel mount usb option: http://www.datapro.net/products/1591.html

-------------------------------
Mr X:

Is this the high quality rca jack that you referred to?

http://www.l-com.com/item.aspx?id=1008

As far as I can tell, it is just a single jack and they don't seem to offer different color choices (red/white/black). Is this correct or am I not looking hard enough?
post #659 of 1562
Quote:
Is this correct or am I not looking hard enough?
Correct, they only sell them individually and they only offer them with a red stripe.
post #660 of 1562
^ Ouch those are expensive. I can get the same thing here for about $3AU in black or red.

http://www.altronics.com.au/index.as...=item&id=P0220
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