RE: Wow: quite a difference from replacing the EQ section op…

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Author: Kaz Kylheku
To: Darrall Dougherty
CC: ada-mp1
Subject: RE: Wow: quite a difference from replacing the EQ section op-amp!

On Tue, 11 Dec 2012 15:35:09 -0600, Darrall Dougherty
<darralld@???> wrote:
> Well I have some 5532's on order. Should get them next week.
> Never done much soldering. So I hope that goes well...LOL

The soldering is easy; it's the desoldering that can be a pain,
especially if you try for getting the old IC out in one piece,
and you just have a regular soldering iron tip.
(There exist special soldering iron bits that can heat
the pins of an IC all at once).

Definitely, you need a spring-loaded solder pump. Also,
solder-wicking braid (the finer the braid, the better it
absorbs). You after pumping away the solder from all
the joints on the bottom side, you may find it necessary
to do some wicking around the pins from the component

One thing that is quite indispensable is a finger
drill, and a set of fine drill bits.
After you get an IC out, you may find that some holes
are plugged up with solder that won't yield to pumping
or wicking. The easiest thing is to re-drill them
with a 25 mil bit.

You need patience. Take the time and don't
force anything.

Swap one thing at a time and test in between, making
sure that chip is doing its job before replacing the
next one.

When soldering an IC in, do not apply too much heat
to a pin for too long. Also, I prefer not to go from
one pin to the next, but to spread the heat around
in a pattern, the thinking being that adjacent pins
convey heat to adjacent areas on the chip.
For something with 8 pins, I do increments of 3
around the circle: pins 1, 4, 7, 2, 5, 8, 3, 6.
If you find yourself heating for more
than two or three seconds, back off, let everything
cool, then do another pin and come back to that one.

Flux is your friend. Apply flux to pins and pads.

Installing sockets is something to think about.
I don't do it for audio, in order not to introduce
mechanical contacts. We already have contacts
in numerous jack-plug connection, tube sockets
and potentiometers.