Open up my Nad C525Bee and found this inside!
Mar 8, 2007 at 4:40 AM Thread Starter Post #1 of 16
flargosa

flargosa

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Mar 8, 2007 at 6:06 AM Post #2 of 16
That's just for vibration damping. Some larger parts will vibrate during shipping and their leads will fail due to metal fatigue. Also some parts will vibrate from loud sounds when playing music and disturb the electrical signals in the circuit.
 
Mar 8, 2007 at 2:16 PM Post #3 of 16
Thought it was a sloppy job or something missed in QA testing.
 
Mar 8, 2007 at 2:43 PM Post #4 of 16
Quote:

Originally Posted by flargosa /img/forum/go_quote.gif
Thought it was a sloppy job or something missed in QA testing.


Nope, it actually means they're working harder to give you a better performing, longer lasting product.
smily_headphones1.gif
 
Mar 8, 2007 at 6:14 PM Post #5 of 16
I am wandering whether the need to have those 'glue' was due to wave soldering (creates less sturdy joints). But I hardly see how you can wave solder a cap. I could be wrong though.

The only reason I bring that up is because I have not seen that kind of stuff in other hi-end equipments.
 
Mar 8, 2007 at 7:14 PM Post #6 of 16
It's interesting, that looks more like a bread board than a circuit board with all those connection wires on the top. The bottom is probably full of those too, so there might be no traces in the board itself.
 
Mar 8, 2007 at 9:06 PM Post #7 of 16
Mostly likely the white glue is an RTV staking material to keep the components from moving during shipping and vibration. It does look kind of sloppy though.
 
Mar 8, 2007 at 9:49 PM Post #8 of 16
The white stuff is "electron froth." It comes about because of a mismatch between the flux capacitor and the drizzle diodes. I'm sure you can find an aftermarket supplier to provide upgraded components, but first you have to very accurately find your latitude and longitude. The froth causes no damage but is unsightly.

Now, if you live in certain areas, there's a real problem with square electrons, which makes the choice of drizzle diodes much more difficult. Your local audio expert can give you relevant advice.
smily_headphones1.gif
 
Mar 9, 2007 at 12:13 PM Post #9 of 16
Quote:

Originally Posted by rad212 /img/forum/go_quote.gif
It does look kind of sloppy though.


It's applied with something like a cotton bud. How neath do you want it to look? It's a glue that is very elastic in nature.
 
Mar 9, 2007 at 11:51 PM Post #11 of 16
Quote:

Originally Posted by chesebert /img/forum/go_quote.gif
I am wandering whether the need to have those 'glue' was due to wave soldering (creates less sturdy joints). But I hardly see how you can wave solder a cap. I could be wrong though.

The only reason I bring that up is because I have not seen that kind of stuff in other hi-end equipments.


Wave soldering is a industrial mounting method used on plated-through-hole components. The components are placed on the pwb and the component legs are bent and cut so that there is no gluing needed to hold the component on place when the board is drawn over the solder wave. You can of course use wave soldering for smd components also, they just are glued on the pwb. Smd components are soldered also by reflow.

Im not sure, if this was the case
rs1smile.gif


What comes to the glue-like substance, my best guess is that it's used to secure the possibly heavier components to the board..
 
Mar 10, 2007 at 1:52 AM Post #12 of 16
Quote:

Originally Posted by Paavola /img/forum/go_quote.gif
Wave soldering is a industrial mounting method used on plated-through-hole components. The components are placed on the pwb and the component legs are bent and cut so that there is no gluing needed to hold the component on place when the board is drawn over the solder wave. You can of course use wave soldering for smd components also, they just are glued on the pwb. Smd components are soldered also by reflow.

Im not sure, if this was the case
rs1smile.gif


What comes to the glue-like substance, my best guess is that it's used to secure the possibly heavier components to the board..


I think you missed my point: which is wave soldering creates an inherently weaker joint contact and the white glue is used to hold it in place for shipping. Had the soldering been done with good old manual labor, you wouldn't need white glue. (this is just my theory)
 
Mar 10, 2007 at 2:10 AM Post #13 of 16
actually, gluing capacitors and certain other passive components minimizes vibrations, which are a cause of distortion. mundorf recently published a paper proving this effect.
 
Mar 10, 2007 at 10:18 AM Post #14 of 16
Quote:

Originally Posted by chesebert /img/forum/go_quote.gif
I think you missed my point: which is wave soldering creates an inherently weaker joint contact and the white glue is used to hold it in place for shipping. Had the soldering been done with good old manual labor, you wouldn't need white glue. (this is just my theory)


Wave soldering creates as good joint as manual soldering. I have not seen any documents of wave soldering being weak and therefore that components need support. Wave soldering is a very common, and old method. Manual soldering is used very rarely nowadays due to price and speed. It's just not better. So, in my strong opinion, the glue is not needed for wave soldering. Instead cotdt has the point, components do vibrate in use. The amount of distortion due to the movement of the component is not familiar to me.
 
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