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y1 gamma-1 DAC - Page 17

post #241 of 1535
1/10/09 at 7:33pm
Also, when checking the dac board only, I do get 3.3v from that test point, but 5.2vdc from the 4.75 test point.
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post #242 of 1535
1/10/09 at 8:15pm
From a few pages ago:

Quote:
Originally Posted by amb
Nothing will cause the voltage regulator to output more voltage than what it's supposed to output, unless its ground reference pin is not making contact to circuit ground, or there is a short circuit from its input to output (which could be an internal short due to a blown regulator, or a solder bridge somewhere, or a PCB defect).

Quote:
5.2vdc from the 4.75 test point.
What is the supply voltage?
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post #243 of 1535
1/10/09 at 8:31pm
Quote:
Originally Posted by MisterX View Post
From a few pages ago:
I've already reflowed the joints and replaced the 3.3 regulator once. Should I try replacing the 3.3 regulator again?


Quote:
What is the supply voltage?
5.2 VDC. Same as the 4.75 test point reading.
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post #244 of 1535
1/10/09 at 8:35pm
Quote:
Originally Posted by srserl View Post
I use the same temperature (325C) for SMD or through hole; the temp depends on the type of solder you use (lead/tin, or lead-free). At this temperature, I find it takes 1.5-2 seconds per pin on IC smd, 1.5-2 seconds per side for 0805 size smd, and and 2-2.5 seconds per side for 1206 size smd. Through hole soldering at this temp takes 2-4 seconds per joint, depending on the size of the leads.
For lead-free solder, I use just over 375C, but I have only done a small bit of soldering with it so far.
Thank you for your input. Can't wait to get these projects started.
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post #245 of 1535
1/10/09 at 9:34pm
Quote:
Originally Posted by Daveze View Post
TBH, I absolutely loath SMD. I've been resisting it for a while but should I get an adjustable temp iron? As I got towards the end of the SMD soldering I was seriously wondering which would be more painful: continuing with the soldering or just sticking the iron in my right eye. I'm using a 55W (I think) Goot pencil but with the fine tip its nigh impossible to keep the tip tinned, which meant I had a mongrel of a time getting good heat transfer into the joints.
Hey mate. I used one of these flux pens from Jaycar and this video guide.

Worked an absolute treat.
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post #246 of 1535
1/10/09 at 10:37pm
Quote:
Originally Posted by bperboy View Post
I've already reflowed the joints and replaced the 3.3 regulator once. Should I try replacing the 3.3 regulator again?
I wouldn't, you already replaced it once and it didn't help. Right?
What is the exact problem @ the 3.3volt test point?



Quote:
Originally Posted by bperboy View Post
5.2 VDC. Same as the 4.75 test point reading.
So you know what to look for on U6D?
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post #247 of 1535
1/10/09 at 10:53pm
Quote:
Originally Posted by MisterX View Post
What is the exact problem @ the 3.3volt test point?
The voltage reading is ~5.0 VDC instead of 3.3 vdc.



Quote:
So you know what to look for on U6D?
Cold joints? I've reflowed this chip as well.
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post #248 of 1535
1/10/09 at 11:08pm
Quote:
Originally Posted by Beefy View Post
Hey mate. I used one of these flux pens from Jaycar and this video guide.

Worked an absolute treat.
Thanks for the link to the video tutorial. A mountain of info in a short video.
Exactly what I have been lookin for.
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post #249 of 1535
1/10/09 at 11:41pm
I've been eyeing this DAC for sometime now and I think its time to update my current iMod Mini (DAC). I actually had a question as to how this DAC compares to others, as I really don't see direct comparisons. Curiously I was wondering how it fairs to the Music Fidelity V-DAC, since I heard some glowing reviews about it at a local HiFi store.
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post #250 of 1535
1/10/09 at 11:49pm
Woo Hoo!!! I finished my gamma1 and it works perfectly... My toughbook on the other hand is really fighting me with the settings to run the DAC with. When I finished testing, I plugged in the USB cable and the note at the tray said: new hardware found, Audio DAC found, human interface device found, new hardware installed and ready for use. Thats it... no matter what settings I use on the laptop, no sound. I'm running it with my mini3. I connected to the back of my DVD player through the coaxial port and I can hear the movie playing just fine. sigh....

P.S. I spared you guys the pictures, since it looks exactly like all the others shown.
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post #251 of 1535
1/10/09 at 11:51pm
windows sucks...

look around for control panels for audio. try to make the usb audio 'speakers' your default device in the audio control panel (the generic windows one).

make SURE the faders are all the way up.

also do a reboot - since sometimes there are 'internal' windows volume sliders that get set and not reset by the user.

de-install (x-out) existing audio devices, then plug in your usb device and set that as the default windows device for sound.
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post #252 of 1535
1/11/09 at 12:11am
Quote:
Originally Posted by bperboy View Post
Cold joints? I've reflowed this chip as well.
Show me.
(let's make sure you have all of the chips in their right spots and so on)


vixr:
You sure you have all of the jumpers in the right spots?
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post #253 of 1535
1/11/09 at 1:35am

4 Gamma Ones Live

I finished up my 4 Gamma ones....all working wonderfully! This is a very nice DAC, and a great companion to the Mini3.
I tried an experiment on soldering the ICs this time by using only a flux pen on the PCB traces and on the bottoms of the IC legs. It works very well when the tinning on the PCB is thick, and makes an extremely clean job, but I got a few dry joints where the tinning was not real thick. I checked continuity of every lead with a Fluke meter, but that isn't good enough using this method. I also had to mechanically check every lead by pushing sideways on it with a small screwdriver also. After suplementing the dry leads with a small dab of solder, all was well, and each DAC is working flawlessly. I find using a microscope for all my soldering on a PCB this tight is very helpful.
The planning that AMB put into this project is astounding.....very nice job and excellent support as usual!
My photo host is down right now, but I'll post a few pictures later.
rjkdivin
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post #254 of 1535
1/11/09 at 2:27am
Quote:
Originally Posted by MisterX View Post
Show me.
(let's make sure you have all of the chips in their right spots and so on)
Hope quality is good enough; I'm lacking a macro lens.




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post #255 of 1535
1/11/09 at 3:44am
bperboy, I'm a little confused by what you reported. You said that you were getting 5V out of both the 3.3V and 4.5V test points, and then you said that you had 3.3V. So which is it? And on which board?

The photos you posted aren't clear enough for me to discern the markings on the voltage regulator chips. Can you tell me what it says on U3U, U5D and U6D?
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