Some further thoughts about microphone cables...
1) For maximum RF rejection, consider soldering the shell of the XLR
to pin one. This extends the shielding over the inside of the XLR,
where the cable shield is no longer enveloping the inner conductors.
Most XLRs have a metal tab that connects to the shell for this
purpose (it is usually located above and between the connections for
pin 1 and pin 2). However, bear in mind that such a cable might cause
earth loop problems if used with anything that is mains powered. It
will be fine for microphone cables (unless being used with a
microphone that requires an external mains power supply, such as a
valve/tube microphone) and any portable battery-powered devices.
2) If you're making a two-way cable as I have described/recommended
elsewhere, make sure you label the breakout cables appropriately. I
use Neutrik XLRs; on the underside of the shell is a small indented
circle (about 4mm diameter) with the Neutrik 'N' logo in it. I fill
this hole in with a small blob of Humbrol enamel paint - the kind
made for painting model trains and similar, and sold in tiny little
paint tins. Because it is recessed into the indented logo, it doesn't
wear off in a hurry. It's a small subtle dot because my cables are
often used in concert halls and need to be 'heard but not seen' -
hence black cable, black XLRs, tiny little coloured dots, etc.
'Louder' methods of colour coding include using coloured 'boots' (the
screw-on plastic/rubber bit at the back of the XLR that also tightens
the cable retention clamp is called the 'boot'). Neutrik make
coloured replacement boots in all 10 colours of the resistor colour
code. They also make plastic rings that can be fitted on the XLR
after assembling, which are also available in the resistor colour
code.
http://www.neutrik.com/fl/en/audio/204_317759770/XLR_Cable_Connector_A
ccessories_productlist.aspx
When colour coding, choose colours that are intuitive and/or make
sense to you. I use red for my left channel and green for my right
channel, as used by Nagra for all of their schematics, and in
accordance to the maritime standard of red for port (left) and green
for starboard (right).
The standard of red for right and white (or sometimes black) for left
is a consumer hi-fi standard; you can use that if you want.
The red/green maritime standard comes in handy when I have to draw up
a complex wiring plan on paper; I can draw red and green lines for
left and right. I can't draw a white line on a sheet of paper, and I
like to reserve black for common things like power wiring and
similar. But use whatever floats your boat, so to speak...
If you intend to work in the dark, consider writing/painting a number
or letter on the connector as well, because colours can be harder to
identify in moonlight.
3) Still on the topic of colour coding, when you make a breakout
cable from a two-channel cable you should use heat-shrink tubing over
each of the inner cables to protect them, and a larger diameter piece
over the point where the internal cables break out from the outer
insulation. They already have an insulating cover, but it's not very
strong. Heat-shrink tubing is readily available from any electronic
component supplier and comes in a range of colours, so you can colour
code each leg of the breakout that way.
4) When making a breakout cable, be sure to make the breakout part
long enough for all of your needs! My first one had the left and
right channels coming out in two separate leads, each about 20cm
long. I sometimes find myself using an AB pair of omnis, spaced up to
50cm or so apart, so 20cm on each side wasn't long enough. I've since
made a new breakout cable that has about 30cm for each channel, no
problems.
- Greg Simmons
"While a picture is worth a thousand words, a
sound is worth a thousand pictures." R. Murray Schafer via Bernie Krause
------------------------------------------------------------------------
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/naturerecordists/
<*> Your email settings:
Digest Email | Traditional
<*> To change settings online go to:
http://groups.yahoo.com/group/naturerecordists/join
(Yahoo! ID required)
<*> To change settings via email:
<*> To unsubscribe from this group, send an email to:
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
------------------------------------------------------------------------
|