Author Topic: Cosmopolitan problem: Low sound [SOLVED]  (Read 5031 times)

2tonewarrior

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Re: Cosmopolitan problem: Low sound
« Reply #15 on: March 30, 2012, 08:11:14 AM »



« Last Edit: March 30, 2012, 08:13:48 AM by 2tonewarrior »

jkokura

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Re: Cosmopolitan problem: Low sound
« Reply #16 on: March 30, 2012, 08:16:15 AM »
Thanks for all your pictures, but as mentioned already you need to change out the capacitors for the correct values. Let us know what it's like after you've done that.

Jacob
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2tonewarrior

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Re: Cosmopolitan problem: Low sound
« Reply #17 on: March 30, 2012, 08:21:54 AM »
I got lost. What capacitors are wrong?

cjkbug

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Re: Cosmopolitan problem: Low sound
« Reply #18 on: March 30, 2012, 08:23:32 AM »
The codes on your wimas  look to me like the values you used are off. I don't know how experianced you are so don't take it hard but I'm gonna see if I can find my conversion chart for pf nf uf.  I had a hard time understanding them at first.  basically 1000pf = 1nf = .001uf... it looks like your code 1k 63 would be 1k(1000) pf or 1n or .001uf with a maximum voltage rating of 63 volts.

Please someone weigh in if I am off track as I am not familiar with these particular codes. don't always assume the supplier put what you ordered in the little plastic bags. they screw up values all the time. it's pretty easily done.

Sorry, but you're off with the capacitor codes.  u1 = 0.1uF, K = 10% tolerance, 63 = 63V.
I stand corrected
I got blisters on my fingers!!!

jkokura

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Re: Cosmopolitan problem: Low sound
« Reply #19 on: March 30, 2012, 08:37:12 AM »
Sorry, I read that someone found some wrong values, didn't realize that had been in error. I'll take a closer look if I can later.

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gtr2

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Re: Cosmopolitan problem: Low sound
« Reply #20 on: March 30, 2012, 09:06:59 AM »
You may have a bad solder joint somewhere.  It doesn't look to my eye that the copper clad was cleaned with a scrubbing pad etc.  Etched boards take more prep work for the solder to properly adhere.  A bad joint may look good from the outside but it may just be "resting" on the copper and not melted to it.

I've had this experience with an etched fuzz face when I was starting out.  It was an etched board and I was getting a signal but it was very weak.  There were a few bad joints just resting on the copper.  Once they were fixed by removing the solder and scuffing the copper pad then resoldering.  It worked as it should.

To me it looks like you were having trouble getting the solder to wick to the copper.  I base this off of the excess amount of solder at your joints.  I could be wrong, it's just my observation.

Your best bet now is to take an audio probe and follow through the schematic, beginning at your input.

Good Luck!  We've all had our share of troubleshooting headaches.   ;)

Josh
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2tonewarrior

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Re: Cosmopolitan problem: Low sound
« Reply #21 on: March 30, 2012, 12:30:17 PM »
Quote
You may have a bad solder joint somewhere.  It doesn't look to my eye that the copper clad was cleaned with a scrubbing pad etc.  Etched boards take more prep work for the solder to properly adhere.  A bad joint may look good from the outside but it may just be "resting" on the copper and not melted to it.

I've had this experience with an etched fuzz face when I was starting out.  It was an etched board and I was getting a signal but it was very weak.  There were a few bad joints just resting on the copper.  Once they were fixed by removing the solder and scuffing the copper pad then resoldering.  It worked as it should.

To me it looks like you were having trouble getting the solder to wick to the copper.  I base this off of the excess amount of solder at your joints.  I could be wrong, it's just my observation.

Your best bet now is to take an audio probe and follow through the schematic, beginning at your input.

Good Luck!  We've all had our share of troubleshooting headaches.   

Josh

You are probably right. I think IŽm gonna remake the pcb. I think the solder joints are not the problem but the copper, it has a little dents because the etching mix was too hard. I was exciting about starting the project and went on because I thought that could be not a problem. As all values are right and all other things seems to be ok that could be the real problem.

Thanks all for your time and your help  ;), when IŽll get the new PCB mounted IŽll return to show it (hope I will return with good news)

2tonewarrior

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Re: Cosmopolitan problem: Low sound
« Reply #22 on: April 02, 2012, 04:39:28 AM »
Good news everyone! I really hate desolder but in this case it was worth. Changed the PCB and sounds good now :)

gtr2

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Re: Cosmopolitan problem: Low sound
« Reply #23 on: April 02, 2012, 05:50:19 AM »
Excellent!!!

Josh
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