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tubstermania  
#1 Posted : Saturday, March 30, 2013 3:43:46 PM(UTC)
tubstermania

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So I built the amp for SE, and used the LSBPS.
Sound comes out of both channels, but the sound isn't very loud, (louder straight out of IPod for example), and it is very distorted.
It appears, from what my multimeter says, that FB has been shorted to GND on both boards.
My soldering skills aren't fantastic but from what I can see, there are no shorts. here are pictures of the build.
The jumpers are there due to multimeter readings of lost connectivuty, but they didn't affect sound, so I will remove them after, cheap multimeter I guess


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Edited by user Saturday, March 30, 2013 3:44:19 PM(UTC)  | Reason: Not specified

Corpius  
#2 Posted : Saturday, March 30, 2013 6:46:01 PM(UTC)
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Looks to me that there are some bad solder joints. Use more flux or heat. Perhaps the type of solder does not flow very well. I have had some solder before that did not flow at all. What solder are you using?

A good solder joint should be vulcano shaped. Like this:
good vs bad solder joint

.

Edited by user Saturday, March 30, 2013 6:48:45 PM(UTC)  | Reason: Not specified

tubstermania  
#3 Posted : Saturday, March 30, 2013 6:53:31 PM(UTC)
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Originally Posted by: Corpius Go to Quoted Post
Looks to me that there are some bad solder joints. Use more flux or heat. Perhaps the type of solder does not flow very well. I have had some solder before that did not flow at all. What solder are you using?

A good solder joint should be vulcano shaped. Like this:
good vs bad solder joint

.


So you think if I go fix all my solder joints, then ill be good to go?

Corpius  
#4 Posted : Saturday, March 30, 2013 7:02:22 PM(UTC)
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That's what I would do, but I can not promise you that it really solves the problem.
Brian Donegan  
#5 Posted : Saturday, March 30, 2013 8:33:12 PM(UTC)
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Ok, a couple of things jump out at me.

First, the voltage regulators (LM317 and 337) need to be properly heatsinked, or it will cause all sorts of problems.

The grey insulators are like stickers, and should be stuck to the heatsink (aligning the mounting hole). Then put the black shoulder washer in the vregs tab hole, and use the screw and nut to hold it very tightly against the heatsink.

Second is the solder minarets. It looks like a lot of joints have solder on the part pins, but are not properly flowed to the board.

Curious, why did you solder the power rather than use the terminal blocks?

tubstermania  
#6 Posted : Saturday, March 30, 2013 8:57:26 PM(UTC)
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Originally Posted by: Brian Donegan Go to Quoted Post
Ok, a couple of things jump out at me.

First, the voltage regulators (LM317 and 337) need to be properly heatsinked, or it will cause all sorts of problems.

The grey insulators are like stickers, and should be stuck to the heatsink (aligning the mounting hole). Then put the black shoulder washer in the vregs tab hole, and use the screw and nut to hold it very tightly against the heatsink.

Second is the solder minarets. It looks like a lot of joints have solder on the part pins, but are not properly flowed to the board.

Curious, why did you solder the power rather than use the terminal blocks?



Well I kinda cut the regulators beforehand, so I think If i pull them out more, the pins wont go in anymore, so Idk if I can screw them in. But, ik this needs to be fixed, but is this causing bad audio, I would like to solve the audio issue first :D

Second, so you mean like the top is soldered, but its not connected to the board I assume, so I should check all my solder joints?

and what do you mean by the last q? lol

tubstermania  
#7 Posted : Saturday, March 30, 2013 10:04:36 PM(UTC)
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I checked the solders on one of the boards, and fixed all the ones that I thought needed fixing. No change in audio. So, i'm fixing the regulators now.

If that doesn't work, could it possibly be that I fried the buffer or OPAmp?
tubstermania  
#8 Posted : Sunday, March 31, 2013 1:29:45 AM(UTC)
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Its not going well. I fixed up the regulators, no change. I thought I fixed the solder in the amp boards, no change at all. Now also, the earbuds get really hot too. Idk if thats part of the same issue, but if it is, that might help track down the problem.
gwikse  
#9 Posted : Sunday, March 31, 2013 3:22:13 PM(UTC)
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Russ / Brian : Should CC1 be mounted in this case?

Edited by user Sunday, March 31, 2013 3:28:23 PM(UTC)  | Reason: Not specified

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Corpius  
#10 Posted : Sunday, March 31, 2013 4:03:43 PM(UTC)
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Why do you have wires soldered from the input to the capacitor and from there to another capacitor?
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kesgreen  
#11 Posted : Sunday, March 31, 2013 5:39:33 PM(UTC)
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Suggestions:

Get rid of CC1 on both boards, you won't need it.

Desolder all the wires on the underside of the board. You don't need any wires there. The input/output wires go into the terminal blocks (the green plastic things) and you tighten down the top screws.

Ensure that all the solder joints make a good connection between the component legs and the copper pad on the board. When soldering, make sure you touch both with the iron and let the solder flow over both.

Ensure close contact between the heatsinks and regulators by using the screws. Without close contact, the heat will not move into the heatsink to be dissipated. See here: http://sound.westhost.com/heatsinks.htm

After all work is done, give the board a little clean with some flux remover/isopropyl alcohol.

Brian Donegan  
#12 Posted : Monday, April 1, 2013 2:22:56 PM(UTC)
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You might want to give this a read: http://www.twistedpearau...ur_first_module_V1.1.pdf

Leon wrote it a while back using some pictures I provided, some of which detail how to mount the voltage regulators properly.

It would very likely be that you have killed the vregs by overheating them (not cooling them enough). You should be able to tell after properly mounting them.

What voltage are the power supply rails adjusted to?
Jordo  
#13 Posted : Tuesday, April 16, 2013 11:13:33 PM(UTC)
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Hi Tubstermania,

Are you still experiencing the distorted sound?
I have it to on one channel...

Did you find something already?

Cheers,

Jordo
Jordo  
#14 Posted : Thursday, April 18, 2013 12:15:49 PM(UTC)
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Ok, mine problem is solved :)

I did (again) switched some wires and put it al in the right sockets.
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