Alien DAC v1.1 Construction Thread - Page 50

just built one

I just ordered and built my kit from glassjaraudio.com. After much eye-straining and trial and error i got it working, sounds better then my creative EMU10k. The bass is REALLY tight, its like going from a crappy 15" sub in a sentra trunk to a nice tight 8". The highs sound the same to me, except for the fact that I'm discovering things in my music I've never heard before. Kinda like "oh wow, there is a whistle in this song!". Also Portishead is listenable without the "OMG my head is going to split" effect! The kit i ordered came with the Elna Silmic II(sp?) caps. Didn't try any others.

Here is a little advice that i found sprinkled throughout this thread (and a little of my own.)

1. Install the 3.3v and 5v regulators and associated resistors and caps FIRST. Then test them, make sure you get the expected voltage levels out at both test points. If you have a bridge on the ssop28 it will most likely drag one of these rails down and you won't know if its a regulator or ssop28 problem.

2. Flood and suck worked great, BUT you seem to get alot of bridges BEHIND the pins. Put the board ontop of a BRIGHT flashlight (i found a 5led white flashlight to work best) and look at it with some sort of magnification. Your just not going to see it with the naked eye. I have a astigmatism that allows me to take off my glasses and shove things an inch from my eye and focus on them, and even then i was unable to see some bridges.
I also found it IMPOSSIBLE to move the iron out and sucker into place. I had much better luck using the iron and sucker together, its a squeeze but can be done.

3. The left side (usb connector side) of the ssop28 is the "digital" side, it uses the 3.3v regulator. If your 3.3v test point stops showing 3.3v this is your problem. This will also usually make your dac not show up correctly when plugged into your PC's usb port. The usb data connections are also here.

4. The right side of the ssop28 is the "analog" side, it uses the 5v supply. If your 5v test point isn't 5v, look for bridges here. Also if you dac is SUPER quiet (you have to blast your amp and volume settings) or the output sounds like crap you prob have a bridge here also.

5. Solder in a loop of wire to S1 so you can externally power the DAC easily (with a current limited power supply! My DAC pulls .03amps idle, when i had a bridge i had limited the power supply to .1amps which is NICE, no POOF!). Also insert loops of wire (cap cutoffs work good) for the 5v and 3v test points. Now you can power and more importantly clip your multilmeter onto these points. The USB connector itself makes a good ground point.

I know everyone always wants a pic, but i had to almost completely disassemble my DACs right side. It was SOO pretty the first time i put it together, but alas it didn't work (5v short). I'm currently burning it in at work with my PPAv2 before i case it, here is a shot of it, its IN the final case, just needs a little rear panel work (its rear facing in pic)

My local Farnell seems to have run out of REG101s. I want to build an unregulated USB version asap. Can I use any 3.3V regulator instead? Or is a substitute available?

The most similar pinout SO-8 regulator I could find is LE33CD. I assume it'll work with a few choice pins lifted. From the datasheet, minimum output capacitance needed is 2.2uF, so the 100uF Pana FMs I bought should work better.

Maybe I could also air-wire TO-92 LDO regulators or LM1086. I figured SO-8 LE33CD is the neatest option though. Looking for better performing ICs though, even if air-wiring is involved.

bump

Finally

After having my kit from glassjaraudio.com at home for a long time, i finally started bulding last week, and now i am listening to sweet music

Only have the enclosure to figure out first But that will have to wait since i now have the unenclosured DAC at the office

/Erik

just picked up my package from jeff this afternoon..
the first thing I really noticed though with the sound is the sound stage, WOW. no comparison to my ipod line out. It's like I walked out into the open, niice really clean and as tsaavik said, the bass is nice and tight, controlled... (gee, I see myself using these words now too.. ahh, the bliss ) it does sound slightly subdued though but I do have 22microF behind the output.. its still much tighter and I rather prefer it, I'll see how it burns in and will probably experiment a bit here someday. will get some pics up sometime too..
Jeff, thank you! and thank you head-fi (except, as you know.. my wallet hates you :P )

-ruZZ

p.s: tsaavik, I did flood and absorb(using that braided stuff..). worked fanschmasticly. (I think I may have read this at tangents, thanks! )

Interesting thread

Managed to get REG101s and finish one board. Sounds great so far. Unregulated USB with 22uH inductor config. Will build battery/TREAD powered versions to compare.

I had to file the PCB to make it fit between the screw posts.





Case: Hammond 1593K

Anyone here using an Alien DAC under Linux? It works, but I get an annoying burst of static noise when changing from one song to another, or sometimes when player app is open but not playing. There is no noise during playback. This occurs with several different player software apps (xmms, amarok, xine, mplayer, softsqueeze) I tried, so it's not a problem there. This problem doesn't occur under Windows XP, so it's definitely not a problem in the Alien DAC hardware.

I also experienced the same thing with an M-Audio Transit USB under Linux, but the motherboard audio doesn't exhibit this problem. It seems like a Linux USB sound driver issue. I have also tried this on multiple computers just to make sure it's not isolated to one machine.

I know this is probably not the best place to seek solutions to software issues but just thought I'd ask in case someone has BTDT and perhaps found a remedy... I use my Alien DAC on my Linux box often and would really love to get rid of the noise.

Can't help you on the Linux, Amb, but I did finally build one of these things (been a little busy with Millett MAX's):




It worked the first time out - well, once I realized I had to jumper the switch position, that is. It's a USB-powered regulated version using Nichicon Muse ES for CL/CR. The bass is really thumping - - and the highs are much more extended and smooth than I was expecting.

All these months, my primary source has been an M-Audio Transit, mostly with FLAC files or CD's in the PC drive. I was very surprised to hear more detail, dynamics, smoother sound and better bass within a few hours of plugging it in. It's running circles around the Transit.

The build went pretty well, but I was so excited at successsfully soldering in the PCM, I proceeded to solder the first regulator in backwards. A big blob of solder on both sides with a screwdriver underneath and it lifted off nicely - turned it around, soldered it back down and everything was fine. Those SMD capacitors are something else, though - can't tell whether they're flat or on their sides. Apparently, it makes no difference, though.

Very cool project! Many thanks to Alf and I'm building more!

I regularly use my AlienDAC with my Linux laptop and haven't experienced any such issues. I'm running Ubuntu Gutsy on kernel 2.6.22. All the players I use are configured to use ALSA directly to the AlienDAC (hw:1,0), with Gnome configured to use the onboard audio (hw:0,0).

In fact, the audio is smoother than on my much more powerful Windows box which seems to empty the buffer occasionally, producing annoying clicks.

I'd suspect some kind of software issue, though it's suspicious that it's happening on all your machines. What distro and kernel are you using?

I was also surprised with my PCM2702 DAC (Damian's / Unisonus), although my M-Audio FireWire Audiophile measures better I think I like the sound from the 2702 better (paired with my QRV04)

/Tobias

SUSE 10.0, kernel 2.6.13. All the players I use are configured to use ALSA directly.

All I can suggest is try a newer kernel, it seems the hardware itself can work properly with Linux from my experience.

OK, I'm on a roll now. Now that I'm over my fear of that SO-28 chip, these things are fairly straightforward (relatively speaking). I threw another one together today. This one is identical except it uses the 47uF Black Gate NX-HiQ's. You guys are right, I'm afraid: the BG's are noticeably better, right off the bat. If they're supposed to get better from here, that's really saying something. Bass is not as powerful as with the ES's, but the resolution, dynamics and high end detail is superlative. Of course, the bass is supposed to get better with time, anyway.

I have a couple of 0.22uF Sonicaps as Dsavitsk recommends on the ES's - and will give them a try if I can figure out how to bend the leads to solder to the existing pads. According to his reviews, that should increase the resolution with the high-end details on the ES's.

Regardless, both of these handily beat every other source in my house:



EDIT: Further listening confirms these differences. I think I still prefer the ES's - their bass is super-powerful and extends much lower than the BG's without any hint of roll off. The BG's are still smoother resolving top end details. I suppose this could change as time goes on ...