deal only in batteries and they may be
able to recycle. Many "big box" stores
have recycling available for rechargeable batteries. You just have to ask at
places dealing with products that are
prone to battery power.
#2 Visit your local Lowe's store. The
ones in my area of the East Coast have
a recycling bin near the returns
desk that takes CFLs and rechargeable
batteries. No muss or fuss, just drop
Home Depot also takes them at the
customer service desk. I just box them
and mark the box 'Battery Recycling' and
there has been no problem.
[#10134 - October 2013]
Can Resistors Make the
I'm working on an audiophile-quality all-transistor amp. I was told
that carbon film resistors are less noisy
than wire-wound precision resistors —
which are more expensive. Could I
hear the difference in resistors? Is there
a theoretical noise difference?
Carbon composition resistors are
THE WORST THINGS TO USE in an
audiophile amp as their "absolute
value" tolerances range from 10-20%.
Plus, their "absolute resistance" values
are very susceptible to heating and
cooling effects (i.e., they get warm and
their resistance changes — sometimes
Instead of using wire-wounds, use
metal-film resistors. Their tolerances
are 5% or less, they're very stable
overall, and aren't as susceptible to
temperature effects like carbons.
Plus, they're much cheaper than
[#10135 - October 2013]
Audio Amp ICs
I need a good, single-source audio
amp IC for a project. The LM-386 isn't
powerful enough. Is there a 'super'
LM-386 op-amp that's also single-source (only one power connection)?
Depending on your power and
voltage requirements, I would suggest
the LM380 or LM384. I have used
>>>YOUR ELECTRONICS QUESTIONS ANSWERED HERE BY N&V READERS
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November 2013 79
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