Ultra Thin CMoy or other diy headphone amplifier.
May 13, 2012 at 6:04 AM Thread Starter Post #1 of 17

djpharoh

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I was looking to build a CMoy for an eventual diymod iPod but most of the design's I see tend to be pretty chunky, I'm not quite a fan of adding girth to a somewhat large device. I'd like to get it so that the CMoy doesn't add more than a 1/4 inch to the iPod either by having a thin case that placed under the iPod or a pencil/pen size object taped to the side of the iPod. Any ideas?
 
May 13, 2012 at 9:50 AM Post #2 of 17

ClieOS

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1/4 inch is too thin to fit the normal components of a cmoy. A headphone socket is almost 1/4 inch by itself, and you'll have to add the PCB and case around it. A typical rotary potentiometer is usually 1cm so you'll have to opt for the trimmer type. The biggest problem however is the battery. - the common 9V battery is already 3/4 inch thick. You will have to use Li-ion and create a charging circuit for it, probably a step-up circuit as well. If you ask me, that's too much trouble for making a cmoy, which is why no one is making one.
 
May 14, 2012 at 4:20 AM Post #6 of 17

proton007

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The problem with DIY is that components are usually larger, compared to SMD you find on commercial boards, soldered by machines. So a DIY board is always thicker.
If you want you can also give the O2 a try, its total DIY. Much better than Cmoy.
 
May 15, 2012 at 11:35 AM Post #7 of 17

jseaber

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Quote:
I was looking to build a CMoy for an eventual diymod iPod but most of the design's I see tend to be pretty chunky, I'm not quite a fan of adding girth to a somewhat large device. I'd like to get it so that the CMoy doesn't add more than a 1/4 inch to the iPod either by having a thin case that placed under the iPod or a pencil/pen size object taped to the side of the iPod. Any ideas?

 
As already answered, thin and DIY hardly go together. Opamp circuitry isn't the issue. Anyone can solder 1/8W resistors and short thru-hole or large SMD capacitors. But in order to make an amp thin, you have to go Li-Ion or Li-Po. 9V batteries are too thick.
 
Thin aluminum cases are already available. The issue is implementing the Li-Ion circuit. Such designs require tiny components, which beg for machine assembly. Hand assembly would be possible, but extremely challenging to a newbie.
 
May 21, 2012 at 7:32 PM Post #8 of 17

sashaw

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Try using SMD for all the component. Also use Li-Po or Li-Ion battery. Don't use headphone jack, instead, just solder 2 cables to the board and have male and female connector handing outside the enclosure. This way, you are able to make it as thin as pcb thickness + whatever tallest SMD component.
 
May 21, 2012 at 10:01 PM Post #9 of 17

proton007

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Quote:
Try using SMD for all the component. Also use Li-Po or Li-Ion battery. Don't use headphone jack, instead, just solder 2 cables to the board and have male and female connector handing outside the enclosure. This way, you are able to make it as thin as pcb thickness + whatever tallest SMD component.

 
Not that simple. The PCB needs to be made for SMD components, with much smaller dimensions and soldering points. Also, making a mistake means you end up soldering components together, they're pretty close in spacing.
 
May 22, 2012 at 6:40 PM Post #10 of 17

sashaw

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Yes, I understand the difficulty behind it. If someone able to design and get the PCB made, there won't be many components on the board to solder(e.g. RA1). For soldering SMD, it really depends on how good his skill is. This is something I soldered up for testing. When you getting used to it, soldering SMD is not that difficult.
 
 
May 22, 2012 at 10:36 PM Post #11 of 17

ClieOS

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... This is something I soldered up for testing. When you getting used to it, soldering SMD is not that difficult.


There lies the dilemma - if a person has the time and skill to design and make the PCB while learn to solder SMD, he/she is more likely to make a far better amp than a tiny cmoy that is likely to compromise some aspects for the size. It is not that you can't do it, just that it is not going to worth the effort.
 
May 23, 2012 at 1:08 AM Post #12 of 17

proton007

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Quote:
There lies the dilemma - if a person has the time and skill to design and make the PCB while learn to solder SMD, he/she is more likely to make a far better amp than a tiny cmoy that is likely to compromise some aspects for the size. It is not that you can't do it, just that it is not going to worth the effort.

 
Thats true, most of the ppl I know who can solder SMDs by hand do it mostly for correction after designing/testing/modifying the PCB for prototypes.
 
May 23, 2012 at 1:28 AM Post #13 of 17

ClieOS

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Here is something more do-able (and has been done before) - get an FiiO E5 or E6 and swap out the opamp.Probably not going to beat a really good cmoy, but it will be fun project anyway.
 
May 23, 2012 at 5:12 AM Post #14 of 17

sashaw

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Quote:
There lies the dilemma - if a person has the time and skill to design and make the PCB while learn to solder SMD, he/she is more likely to make a far better amp than a tiny cmoy that is likely to compromise some aspects for the size. It is not that you can't do it, just that it is not going to worth the effort.

Very true. LOL
 

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