[LAU] Trying to record!

Chris Caudle chris at chriscaudle.org
Fri Dec 21 16:13:58 CET 2018


On Thu, December 20, 2018 9:18 pm, Bob van der Poel wrote:
> The instrument input actually has more gain available, up to 50dB, so
>> depending on what you need using the unbalanced input
>> might work better.

> That's interesting. I have a 3pin to 1/4 cable laying about. I'll give
> that a go and see what happens. Would this effect the quality of the
> signal?

There are a lot of "it depends" caveats regarding any quality changes. 
You definitely cannot do that for condenser microphones which need phantom
power, and you lose the noise rejection features of a balanced interface
when you change to the unbalanced interface.  For a  short microphone
cable the noise rejection features should not make a noticeable
difference.

One thing which can make a difference with ribbon and dynamic mics is the
input impedance of the amplifier.  This may not be the place to delve into
the specifics of the circuit theory and math, but the summary is that if
the microphone is designed with the expectation of a typical microphone
input impedance in the 1200 to 2000 Ohms range, the frequency response may
be different, likely with a peak in the frequency response, when used into
an instrument input with a typical 500,000 Ohm input impedance.  I love
this stuff, I would pull out some connectors and make adapters with
matching resistors, but spending time on that kind of stuff is one of the
reasons why I do not have good instrument skills, so learning circuit
theory and soldering skills is probably not the way you want to spend your
winter holidays.  :)

tl;dr version: try your normal microphone cable and just turn up the gain
knob, you'll probably be fine.  If it seems not enough gain, try your
adapter cable and see how it sounds if you can do that in 15 minutes time
and not waste a lot of your day messing with equipment instead of playing
your sax.  If you can get your mixer connected in less time than messing
about with adapter cables and listening tests, just do that, you know it
will work.

-- 
Chris Caudle


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