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Alien DAC v1.1 Construction Thread - Page 89

post #1321 of 1560
7/20/08 at 4:05pm
Quote:
Originally Posted by tomb View Post
No, you're not going to hurt your computer, but you may fry the Alien DAC if you've got something out of place. That's the damage to worry about. Check all your parts twice, make sure you've got continuity between your chip pins and the board traces. After that, it's the same for everyone else: strap it in and see if if you can get it off the ground - but watch out for the possibility of a crash and burn.
Plugged it in

Windows recognized it

I have 3.3V between 3.3 test point and G1

and 4.7V between 5 test point and G1

\o/


too bad I dont have a jack to finish testing it though

Thanks a lot for your help guys!
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post #1322 of 1560
7/21/08 at 3:05am

Alien NOS Cap Tester

I found some old caps at my local store recently and was curious how they'd sound with the Alien. I have a small assortment (including the VitQs that TomB turned me on to) and put this little sub-board together so I can try them in different configurations, bypassing or replacing the Nichicon electrolitics that came with the kit I purchased from Glass Jar, without having to solder and desolder my collection.

I'm mostly amused at how it turned out and thought I'd share the mirth with a pic. These Mallards sound just fine but the Alien itself is just built so we'll see how a dozen hours affect things....
LL
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post #1323 of 1560
7/21/08 at 5:45am
turns out I still have a few questions to ask regarding the alien ^^

I built it using a kit made by jeff rossel, from glass jar audio. I still have 2 components left : a resistor (which is supposed to be used to o/c the chip using external ps if I understood properly)
and some sort of dented component. If I look at the spreadsheet that came with the kit, I suppose that would be X1_Acc, a mylar spacer. But what would that be? some thing that i'm supposed to put between X1 and the pcb? is it necessary ?


My other question would be regarding the wiring. If I understood properly, the advantage of 3.5 jack over RCAs is that it takes less room. However, RCAs are less risky for your amp & headphones because they don't create a short circuit when plugged in. Is that all the difference?

And last but not least, is there some sort of tutorial for casing (I'm wondering how I'm going to "lock" the pcb into the hammond case and prevent it from moving. I think somehow tying it to the back panel , where the usb plug is would be the best solution but I don't know how that could be achieved)

and panel mounting jacks/rcas/leds ?

thanks again for your answers to my previous questions and your help
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post #1324 of 1560
7/21/08 at 6:11am
Does the part you referred to as "X1_Acc"

look like this image------>
http://rocky.digikey.com/weblib/ECS/...s/700-9001.jpg

?

If so it is a Mylar insulator and it is not necessary.

The primary difference between a pair of RCA jacks and a single minijack is durability
I guess shorting is also an issue but you should not be connecting your stuffs when it is turned on anyhow so...

Case working tutorial =
Electronic Construction Tutorial Part 3 - Enclosures

And if you read this thread from start to finish you see any number of ways people have "locked" the PCB into the enclosure.
My preference was to just get the tin snips out of the tool box and cut a piece of sheet metal that fit between the board and the end of the case.
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post #1325 of 1560
7/21/08 at 6:33am
Quote:
Originally Posted by MisterX View Post
Does the part you referred to as "X1_Acc"

look like this image------>
http://rocky.digikey.com/weblib/ECS/...s/700-9001.jpg

?

If so it is a Mylar insulator and it is not necessary.

The primary difference between a pair of RCA jacks and a single minijack is durability
I guess shorting is also an issue but you should not be connecting your stuffs when it is turned on anyhow so...

Case working tutorial =
Electronic Construction Tutorial Part 3 - Enclosures

And if you read this thread from start to finish you see any number of ways people have "locked" the PCB into the enclosure.
My preference was to just get the tin snips out of the tool box and cut a piece of sheet metal that fit between the board and the end of the case.
Thank you for your answer Mr X

Yes, that's just the part! I'll see if I desolder X1 to solder it between it and the pcb. I suppose that since things didn't blow up when I powered the alien up, I don't really need it ^^

Thanks for the casework tutorial. I'm going to check other people's ideas in this thread

((((((Regarding the led, am I supposed to use a normal one or a low current consumption one? will it make some sort of difference considering i'm powering from usb?))))) Nevermind, found out that low current Led was better. Low current it will be!

(low current one is 1.9V @ 2mA, normal one is 2.1V @ 10mA. My limited knowledge would tell me not to bother with the low consumption one and to go with normal leds, but maybe I'm wrong)

edit : and huh, is there any point in using shielded wire?
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post #1326 of 1560
7/21/08 at 3:07pm
Well, I bought some cheap, ****ty wire and rca connectors at a small shop and came back to home. I wired those (I think I ll need a few explanations on how to properly wire outputs though ^^) checked the beasts DC offset

and it seemed fine. So I put my headsix and ibuds in for a first test. Sound was coming out of the ibuds.

So I just plugged my SE530 which I'm listening to at the moment. And it sounds great ^^

It's definitely not bass light btw. At least with the headsix and SE530 after it, the bass has some nice punch.

Gonna test it on some classical, but on the few electronic/rock tunes I've tested atm it behaved pretty well

Anyway, I wanted to thank the people from this thread, MisterX, tomb and the others for answering my questions

Thank you again guys!
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post #1327 of 1560
7/22/08 at 9:30am
Quote:
Originally Posted by ruZZ.il View Post
Hey fellas, I seek any suggestions, or confirmation of a dead chip ;(
This DAC was functional for quiet some time, and still partially is:
Sound out of only a single channel (The right one).
I've scoped out the actual chip pin, OUTL, and only get a slight offset, but no signal at all. OUTR is fully functional, so its not a power problem, no data transfer problem.. in fact, other than a single cap and resistor in the way, there's nothing but a faulty chip if 1 channel works perfectly and the other has no signal, or am I missing something? Balance and all other settings are set right, so.. changing chips? or.. any suggestions?
As always, much appreciated
Thanks

-R

Chip changed. Problem solved.
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post #1328 of 1560
7/23/08 at 6:29pm
After moving the caps off an Alien board to more easily listen to different NOS caps (see pic of Frankenstein above), I realize that my life might be simpler moving the last step ortwo of the output circuit onto the another board, too, instead of returning to the Alien board to pass through the resisitors and out to the output jack.

In other words, leave the Alien board at the CL/CR + points and continue past the caps on the second board, inserting resistors and taking my output jack off of the second board, too. Obvious stuff.

Here's my question. What restrictions are there on the type or wattage of 330K ohm resistors should I follow (for R15 and R16), after the caps? I don't really want to use surface mount resistors since I am not space-constrained. Will any ole resistor do, or should I aim for something specific?

Thanks again, folks!

__Roy
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post #1329 of 1560
7/23/08 at 6:44pm
Quote:
Originally Posted by royewest View Post
After moving the caps off an Alien board to more easily listen to different NOS caps (see pic of Frankenstein above), I realize that my life might be simpler moving the last step ortwo of the output circuit onto the another board, too, instead of returning to the Alien board to pass through the resisitors and out to the output jack.

In other words, leave the Alien board at the CL/CR + points and continue past the caps on the second board, inserting resistors and taking my output jack off of the second board, too. Obvious stuff.

Here's my question. What restrictions are there on the type or wattage of 330K ohm resistors should I follow (for R15 and R16), after the caps? I don't really want to use surface mount resistors since I am not space-constrained. Will any ole resistor do, or should I aim for something specific?

Thanks again, folks!

__Roy
Pretty much whatever. I'd use a 1/4W metal film as the rest of the map, maybe 1/8W Dale for simplicity.
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post #1330 of 1560
7/27/08 at 3:32am
Quote:
Originally Posted by Pars View Post
C2, C13, C23 and C33 are mose likely polarized electrolytics, with a stripe or other such marking for the negative lead. CR and CL could be polarized (I have no idea what you used for these). If so, they will also have the negative marked.

The rest of the caps (SMD) should be non-polar so no worries there.
If CL and CR are Muse ES (green) they are non-polar

You could post a photo and we could help check for you.

Jeff
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post #1331 of 1560
7/27/08 at 2:32pm

I assume my error is omitting the ground?

Edit: Nevermind. I added the ground and all is better!

In my ongoing effort to emulate TomB : ) I created a little sub board where I have set up 3 VitQ caps in parallel on each channel and then take the audio out from the sub board, rather than returning to the Alien board and using its SMD components.

I got this cased up and get a bad hum instead of music.

Looking back at the schematic (after plowing ahead, of course), I assume my error was not brininging the ground from the Alien board to a point after the resistors, before the signal ground goes to my audio jack?

I'm moving ahead on that assumption now, but if anyone would be kind enough to confirm the error of my ways, I'd appreciate it.

Here's a simple schematic of what I built -- revealing my error I hope...
LL
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post #1332 of 1560
7/27/08 at 4:08pm

Vitamin-Enhanced Alien in Cedar Box

All better now. The Vitamin Q enhancement idea from TomB and the caps themselved from his Beezar.com.

Sounds wonderful with no time on it yet. Looking forward to listening more...

Thanks again for the support on this forum.

__Roy
LL
LL
LL
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post #1333 of 1560
7/27/08 at 5:56pm
Quote:
Originally Posted by royewest View Post
All better now. The Vitamin Q enhancement idea from TomB and the caps themselved from his Beezar.com.

Sounds wonderful with no time on it yet. Looking forward to listening more...

Thanks again for the support on this forum.

__Roy
Very cool box! Great job, too. (Yes, as you discovered, you needed a common ground between the channels to take back to the board.)
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post #1334 of 1560
7/29/08 at 12:41am
Just how mandatory are C11 and C12?
I think I ended up with 2 pairs of R11 and R12 instead of the caps. Might a .1uf wima cap suffice?
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post #1335 of 1560
7/29/08 at 4:14am
Quote:
Originally Posted by lynxkcg View Post
Just how mandatory are C11 and C12?
I think I ended up with 2 pairs of R11 and R12 instead of the caps. Might a .1uf wima cap suffice?
They are capacitors used to load the crystal properly so that it will oscillate at the correct frequency. Leaving them out cause the frequency to increase slightly, but it will likely be close enough to work properly without them. Don't add a 0.1uF cap here, it's much too large. Try it without the caps, but I would eventually fit them even if it works without.
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