[sdiy] x0x repair questions

[Roman Sowa]

inline...

> I have one repair related question and one general question.  The
> repair-related one is: does anyone have a suggestion for a good way to
> match LED colors?  Particularly BLUE.  The 13 note LEDs are blue, but

the LEDs may drop brightness when overheated during soldering. If you 
buy new LEDs now from single source, they all should have good enough 
matched color. And they get brighter and brighter as the technology 
matures, so simply get new ones in a good store.


> The ground plane in this beast is pretty hard to work with when
> desoldering, even with my temp controlled iron, so I really don't
> relish the idea of replacing all 13 LEDs....

the key is the preheater. When you heat up entire board to 100-150 
degrees Celcius, any soldering on vast ground plane will be a pleasure.
Kinda hard to buy it for casual use, but a walk in kitchen supply store 
may find some workarounds.


> doesn't directly feed the output.  I figured it was the 12V instead of
> 6V supply for the headphone amp, but as I think about it I'm not sure
> that it wasn't possibly the cold solders.  Anyone with more experience
> care to hazard a likely guess? If it was the 12V supply for the
> headphone amp, I'm curious why that might be.

without knowing the part I can only guess that headphone amp was low 
voltage part, so applying 12V to it made it go nuts. Typical headphone 
amps are rated for 5V supply.

Roman