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Subject: Re: how to get "Line IN" to work ...with a non "Line Level" device (ie. microphone)

Re: how to get "Line IN" to work ...with a non "Line Level" device (ie. microphone)

From: BlueChip <>
Date: Wed, 25 May 2005 18:14:36 +0100

The MIC gain on a PC *is* a pre-amp stage ...the gain on the Jukebox is
akin to the "MIC volume slider" under windows ...This "MIC volume slider"
is the SECOND stage amplifier ...The MIC "+20db" thingie, depending on your
sound card, normally equates to a "tick box" which means 'pre-amp on/off'

A MIC preamp can be, as I say, as simple as a couple of transistors (well,
more literally ...and a couple of resistors and possibly a small capacitor
to clean the sound up a bit), the complete circuit you could bodge together
at home with uber-basic soldering knowledge and NO circuit board at all and
it would fit on your baby finger nail - so portability is not an issue
...actually you will have more trouble carrying the tripple-A battery that
you would need to power it ...thinks to self: wonder if you could build one
that would run off a hearing aid battery?

Persoanlly, I put my (massively oversized) archos pre-amp in the front
pocket of the Jukebox case and have cut a small hole so I can feed the
cable direct into the main carry area ...then just plug my mic into the
front pocket instead of direct to the jukebox.

Hope that helps,


PS. is "HTH" HOPE to help or HAPPY to help?

>Thanks for the two quick responses.
>I do have the mike boost on XP on my computer. It says +20db. But on the
>Nomad Juke Box I also have the boost up (to+46db) and I still can't get any
>sound out of the mike.
>Any thoughts?
>About adding on an amplifier, I wanted a portable device that recorded sound
>well that I could carry around and dictate (or more accurately, rant) into,
>the recordings being slated for later podcast.
> >From what I'm reading, I'd have to carry around an amplifier as well. Not
>Any suggestions?
>----- Original Message -----
>From: "BlueChip" <>
>To: "Rockbox development" <>
>Sent: Tuesday, May 24, 2005 3:50 PM
>Subject: Re: how to get "Line IN" to work ...with a non "Line Level" device
>(ie. microphone)
> > If you plug a MIC into a MIC socket (as per your PC) it will work - if you
> > plug a MIC into a LINE socket (PC or otherwise) - the MIC signal needs to
> > be amplified to LINE LEVEL ...there are loads of little amps to do this on
> > the market. The archos AAA powerered one is just a couple of
> > transistors. This news archive holds "this one is cool"/"this one is
> > reviews as and when people saw fit to review them :)
> >
> > BC
> >
> > >I have a good headset (1 ear + mike) from my cell phone. It has a micro
> > >plug. I bought an adapter that changes it to two separate mini plugs. I
> > >can put those two mini-plugs into the mike and headphone jacks of my
> > >computer and they both work. It produces a rich, life-like voice
> > >
> > >But when I try that with the Recorder 20, only the earpiece works. The
> > >mike won't pic up any sound when plugged into the Line IN, no matter what
> > >input I select.
> > >
> > >I tried the same thing on a Nomad Jukebox, and same result.
> > >
> > >So is there some kind of wiring difference here that explains why the
> > >setup works on the computer, but not the portable players?
> > >
> > >Could someone suggest how I could get this headset to work on the
> > >R20? I'd really appreciate it!
> > >
> > >(If not, any suggestions for good headsets that would work on the R20 and
> > >produce good, life-like voice recordings?)
> > >
> > >Thanks!!
> > >_______________________________________________
> > >
> >
> > _______________________________________________
> >
> >

Received on 2005-05-25

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