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Subject: Re: my facts on mics
From: Jakob Heinemann (jakob.heinemann_at_ifsab.se)
Date: 2002-11-01


Hi,

just to mention it; I bought my JBR 6G last summer in US, 1st thing I noted was
that the recording with the internal mic was useless. Since the SNR is 200% when

the harddisk spins, it is hardly possible to even hear anything of the recording
in all the noice.
So I just gave up. Looking for pre-amped mics proved fruitless.
Now I just ordered a couple of the cheap german preamps (thanks for the hints)
and hope it will help me get around that.

But if it is as easy to mod it as you say to fix the internal mic, I may as well
go ahead and do the mod.
Are there some details of this mod at the rockbox-site?
(Don't think I will ever use the US support now that I'm back in Sweden.)

Best regards
/Jakob

(mailto:Jakob.Heinemann_at_writeme.com)

Justin Fisher wrote:

> I'm no sound technician, and I inexcusably did not make controlled
> recordings before and after for comparison, however, when recording (either
> music or from mic) before the mod, things like HDD access created audible
> interference, even with the gain right down. Afterwards, if they were still
> there, they were below the ambient noise from archos playback and I couldn't
> hear it. This was before I switched to Rockbox, which has a lot less ambient
> noise during playblack, so I might listen for noise again, but in summary -
> it was all most unscientific, but there were positive results.
>
> Since it's a quick and easy mod, I'd encourage someone else to try it, this
> time doing it right (making controlled recordings before and after, etc).
>
> I'm a little surprised that more people haven't mentioned interference on
> analog line-in recordings - it was fairly noticable in my recordings.
> Perhaps archos has improved the shielding since I got mine (about a year
> ago).
>
> -----Original Message-----
> From: Matthew P. OReilly [mailto:moreilly_at_moreilly.com]
> Sent: Monday, October 21, 2002 3:59 PM
> To: rockbox_at_cool.haxx.se
> Subject: RE: my facts on mics
>
> I have had no problem with mic noise unless I was using the recorder's
> internal mic. Did rerouting the wires help with that noise as well, or was
> it more EFI noise you were hearing when using an external mic?
>
> Matt
>
> -----Original Message-----
> From: owner-rockbox_at_cool.haxx.se [mailto:owner-rockbox_at_cool.haxx.se]On
> Behalf Of Justin Fisher
> Sent: Monday, October 21, 2002 2:57 PM
> To: 'rockbox_at_cool.haxx.se'
> Subject: RE: my facts on mics
>
> I think I've noted this before, but I don't imagine everyone saw - I
> rerouted the line-in wires in my recorder through the battery compartment,
> thus shielding them from the archos circuitry and HDD (the wires are
> unshielded and travel the length of the case, right up against the
> circuitry). This resulted in the removal of the interference from the archos
> operation and disk spins. Hopefully later model recorders have shielded
> wires now, but if you can hear interference in your recordings that
> corresponds with HDD spins, shielding or rerouting the line-in wires seems
> to be an easy and fairly effective fix.



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