[OtterMarc]

SMEGGER - there's nothing wrong with your pictures. Nice going. Sound nice? I'll be building one shortly. Jeff has sent me one in the mail.

SLAUGHTER, wow, no REG101's. Wish I knew what to suggest. August 2008 would be fine for Aussies - it's their summer now. We've got winter projects to fiddle with!!

I'd throw that in as a separate posting in DIY. Yes?

 

[nysulli]

well, during the 2 week down time i finished up a second alien, but i'm having some issues, namely a very low, static filled output that almost sounds like it has a compressed dynamic range due to some clipping at certain frequency ranges

configuration is unregulated usb power, voltages stable at 4.96v and 3.29v respectively, BG NX-HiQ on the outputs, really just worried that i fried the pcm2702 chip, but i've heard of the congested output on the BG's before their broken in, but i really don't know what that sounds like

so any help would be great

 

[tomb]

Quote:

Originally Posted by nysulli /img/forum/go_quote.gif well, during the 2 week down time i finished up a second alien, but i'm having some issues, namely a very low, static filled output that almost sounds like it has a compressed dynamic range due to some clipping at certain frequency ranges configuration is unregulated usb power, voltages stable at 4.96v and 3.29v respectively, BG NX-HiQ on the outputs, really just worried that i fried the pcm2702 chip, but i've heard of the congested output on the BG's before their broken in, but i really don't know what that sounds like so any help would be great

Actually, the BG's I've used on the Alien sounded fantastic on first startup - output was high enough to make you turn down the volume compared to another Alien. Then they settle into a couple of weeks of bland nothingness before they come back as before.

The "congestion" I referred to with much larger NX's on the Millett MAX is more like a lot of fuzz in between the notes of the music - like a thick soup - but no output level issues and I wouldn't call it "static." (Before break-in, of course.)

I hope it's not true, but you may have a problem.

 

[nysulli]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif Actually, the BG's I've used on the Alien sounded fantastic on first startup - output was high enough to make you turn down the volume compared to another Alien. Then they settle into a couple of weeks of bland nothingness before they come back as before. The "congestion" I referred to with much larger NX's on the Millett MAX is more like a lot of fuzz in between the notes of the music - like a thick soup - but no output level issues and I wouldn't call it "static." (Before break-in, of course.) I hope it's not true, but you may have a problem.

well thankfully i've got 5 more boards, another 2702 chip, as well as half the smd parts needed to finish up another alien, now for the fun part of desoldering the other half of them

 

[korben69]

Hi all !
I've finished my Alien DAC yesterday, and you know what it works FINE !

Many thanks to Jeff !

 

[lmiller]

I have built my second Alien DAC. The first worked with no problem and is fantastic, but the second DAC does not work. I have used fixed regulators for both 3.3 and 5 volts. When powered by an external 8 volt supply (no jumper at S1) or when powered from the USB bus (Jumper at S1) I get 3.3 volts but the 5 volt test point shows 0.11 volts. I have replaced the 5 volt regulator with no change. I have rechecked all components related to the regulator and they all appear to be correct. When I plug the unit into my laptop, I get the sound that it sees the device and it recognizes it with the correct chip number, but I get no sound through the DAC. My suspicion is that the PCM2702 is bad. When I measure resistance from the 5 volt test point to ground I see a short. I was thinking of removing L15 - 18 and then rechecking the 5 volt test point with an external power supply. If I get 5 volts then I will assume the PCM2702 is fried on the 5 volt side.

Any suggestions or ideas? Thanks for any help

 

[Heady]

Quote:

Originally Posted by lmiller /img/forum/go_quote.gif I have built my second Alien DAC. The first worked with no problem and is fantastic, but the second DAC does not work. I have used fixed regulators for both 3.3 and 5 volts. When powered by an external 8 volt supply (no jumper at S1) or when powered from the USB bus (Jumper at S1) I get 3.3 volts but the 5 volt test point shows 0.11 volts. I have replaced the 5 volt regulator with no change. I have rechecked all components related to the regulator and they all appear to be correct. When I plug the unit into my laptop, I get the sound that it sees the device and it recognizes it with the correct chip number, but I get no sound through the DAC. My suspicion is that the PCM2702 is bad. When I measure resistance from the 5 volt test point to ground I see a short. I was thinking of removing L15 - 18 and then rechecking the 5 volt test point with an external power supply. If I get 5 volts then I will assume the PCM2702 is fried on the 5 volt side. Any suggestions or ideas? Thanks for any help

Not sure if the problem I had was same as yours. But I had a similar situation where it appeared the 5V regulator seems to be not working. Turns out, the regulator lead to ground had a cold solder joint. The Alien pcb has this quirk in that the coating on the pads seems to repel solder until it gets quite hot. With the ground leads, unfortunately, the ground plane conducts heat away too fast for the pad to really heat up.

My regulator lead was coated with solder but there was none sticking to the pad. The joint however looks ok on visual examination.

 

[lmiller]

Quote:

Originally Posted by Heady /img/forum/go_quote.gif Not sure if the problem I had was same as yours. But I had a similar situation where it appeared the 5V regulator seems to be not working. Turns out, the regulator lead to ground had a cold solder joint. The Alien pcb has this quirk in that the coating on the pads seems to repel solder until it gets quite hot. With the ground leads, unfortunately, the ground plane conducts heat away too fast for the pad to really heat up. My regulator lead was coated with solder but there was none sticking to the pad. The joint however looks ok on visual examination.

Thanks for the tip I will double check to see if that is the problem. That will be easier than removing the ferrites and then possibly having to replace them.

Lindsay

 

[Basil101]

Hi all,
Just built my first Alien and I was wondering if anyone has a good suggestion for how to make the opening for, and secure the USB port to the plastic end cap of my Hammond 1455C802BK?
Thanks

 

[FallenAngel]

Quote:

Originally Posted by Basil101 /img/forum/go_quote.gif Hi all, Just built my first Alien and I was wondering if anyone has a good suggestion for how to make the opening for, and secure the USB port to the plastic end cap of my Hammond 1455C802BK? Thanks

Drill, then use an exacto knife or just start with the exacto knife by cutting the rectangle over and over until you cut through. Takes about 10 minutes, but it works very well.

 

[Basil101]

Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif Drill, then use an exacto knife or just start with the exacto knife by cutting the rectangle over and over until you cut through. Takes about 10 minutes, but it works very well.

Thanks, I had some needle files to square the hole but how do you attach the USB port to the plastic end cap of the enclosure? I am afraid that using superglue or similar would deform the plastic, any tips?

 

[FallenAngel]

Quote:

Originally Posted by Basil101 /img/forum/go_quote.gif Thanks, I had some needle files to square the hole but how do you attach the USB port to the plastic end cap of the enclosure? I am afraid that using superglue or similar would deform the plastic, any tips?

Oh, simple, just use perf-board, styrofoam or basically anything that will fit the PCB slot and keep the AlienDAC PCB flush against the panel.

 

[Basil101]

Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif Oh, simple, just use perf-board, styrofoam or basically anything that will fit the PCB slot and keep the AlienDAC PCB flush against the panel.

Thanks!
I will probably use perf-board and mount my output jacks to it.

 

[Hubbard0]

I'm getting ready to order my Alien and just had one question.

Are you guys running headphones right off the DAC? I plan to build myself a Millet Hybrid but that will take me much longer and won't be done for another 2 months probably assuming I can even get the PCB, but the DAC will be done within a week of me receiving it. Once I get my RP-21s, can I plug them into the DAC? My other question is about running two outputs. If I put on RCAs for the Millet, can I also put on a headphone jack assuming I can plug in a headphone at all? I obviously will only have one item plugged in at a time.

Thanks for the help, I'm a total rookie to all this.

 

[Heady]

hubbardo,
You need to have a headphone amp after the AlienDAC to drive the headphones.