Low recordinglevel iriver h140

[nuss75]

hi all!
does anybody know what happened to the source/external mic setting.
i use the external mic that came with the player.
i have the line in setting and i use it. But I have to use max gain aswell to hear anything. Its strange! correct me if im wrong, but it should be a fundamental difference between line in and mic.
line should be a sterio connection while mic should be a mono and a feed to power the mic.
im puzzeled.

could anybody enlighten me?

[Febs]

There has never been an "external mic" setting in Rockbox.  The original iriver firmware had one, but the only difference was a difference in software gain.  Use the line in setting for recording with a microphone.

[Davide-NYC]

Mic Input uses the INTERNAL microphone. (the one on the side of the unit)
It is a stereo signal but either channel is identical. (so really dual mono)

Line Input uses the Line In jack on the top of the player.

The playback volume (for both Line Out and Headphone Jack) is determined by the Volume setting on the WRS (While Recording Screen) and the gain settings (Right and Left independently) are determined by the Gain settings on the WRS.

Maybe you have the gain settings too low?
Maybe your microphone is broken?
Maybe you Line In jack is a bit messed up?

Another possibility is that your AGC is turned on and the Max AGC gain is set way low. This would preclude you from raising the microphone gain higher than the AGC Max gain level.

Please report back.

[nuss75]

has the volume control on the recordingscren something to do with the volume of the recording? I thougt it just was a monitor setting so u could listen to the recording while it was recoded at your preferd volume...

Abut the AGC: I have it on voice (fast) , since im recording lectures, and 400ms thats the only two AGC settings I can find. but I cant find the setting that u talked about, the "Max AGC gain" were can I alter it?

[Febs]

has the volume control on the recordingscren something to do with the volume of the recording? I thougt it just was a monitor setting so u could listen to the recording while it was recoded at your preferd volume...

Your understanding is correct.  The volume setting controls only the monitoring volume, not the recording gain.

[nuss75]

Thanks for all the replys!
But one thing puzzels me still.
I thought i was using a condenser microphone since im using the mic that was included with the h140.
in order for it to work it has to have a feed of current say 2v.
so my line in should normally use one of the 3 connectors as a feed. is this possible to have a channal at the same time as a feed on the same connector.
to make a better dynamic range can i put a normal 1,5V (or 2, =3V) battery in serie with the feed current?
glad for tips on to make my recordings louder....

[petur]

the analog input on h120/h140/h320/h340 always provides about 3,7V

[pianoralf]

Thanks for all the replys!
But one thing puzzels me still.
I thought i was using a condenser microphone since im using the mic that was included with the h140.

This effect depends on the impedance of your microphone. Most available microphones have a different impedance to the mic which was included. I could not find a comparable better stereo microphone with a similar impedance. So I tried out several mics. Try to increase the gain to maximum value, (i think +48 db) and use the AGC save mode to find the best recording level automatically.  If it is still to low, you have to use an external preamplifier for your microphone.

[petur]

+48dB will give way too much hiss....

If +24dB is still not enough, consider getting a more sensitive mic or a mic pre-amp

[Heriver]

the analog input on h120/h140/h320/h340 always provides about 3,7V

I want to comment something.

Because of this it has a low impedance at the input (~1kohm).
So, if you connect a high impedance soure to the H1x0 then the signal drops several millivolts,
but then the signal passes a low-pass filter 2700ohm/100uF so you get a mid/high frequency loss to!

If you connect a device to the line-in be sure that your using only pre-amps, mic's  and other devices
that has a low output impedance about 1Kohm or less (and not much higher)!