--- Forwarded Message from Bob Majors <[log in to unmask]> ---

>Date: Thu, 20 Oct 2005 12:52:16 -0700 (PDT)
>From: Bob Majors <[log in to unmask]>
>To: Language Learning and Technology International Information Forum   
<[log in to unmask]>
>Subject: Re: #8044.5 Audio Recording (!)
>In-Reply-To: <[log in to unmask]>
>References: <[log in to unmask]>

> ... why don't you just attach the mic to the
> "mic input" of the computer sound card? I think it is the easiest way to
> record sound directly into the computer. But I don't know whether the effect
> of the sound will be satisfactory.
> Regards,
> Chen Xiaobin

I'm not the original poster of the external mic pre-amp/ USB audio 
converter follow-up message, but there are some advantages of using an 
external USB or FireWire analog converter:

- Balanced microphone inputs, which offer better quality (when balanced 
mics are use) and lower noise. When using an unbalanced mic or mic input, 
longer cable runs (to isolate the mic from the computer acoustical noise 
(fans, hard drive noise)) -- the noise problem of an unbalanced signal is 
increased.
- Often phantom power is available in external boxes, which is required by 
many quality microphones.
- (Usually) better microphone pre-amps.
- (Usually) better A/D and D/A converters.
- The mic pre-amp, which amplifies a *very* low level audio signal, can 
pickup RFI and other noises prevalent inside the computer (from hard 
drives, etc., etc.). This can add noise to a recording.
- An external box is portable (can be used on different computers).
- External boxes have control pots (potentiometers -- knobs) for 
headphone volume and output volume, which are handier to grab and ride 
than adjusting software settings.
- Some audio cards either have mic inputs or line-level inputs, so while 
there are ways to use either for either source, having a dedicated line 
and mic input in an external box is handy.
- The headphone and audio jacks are often less prone to breakage -- 
compare a 1/8" mini jack on a sound card to 1/4" jacks on external boxes.

That all said, in many cases a built-in sound card may do the job just 
fine, depending on the quality desired, the components in use, etc.

Bob Majors
Language Learning Center
University of Washington