Line In problem with H140

[gramit]

My iRiver H140 doesn't  record when using an external microphone through Line In. I have tried it with two mics, a Giant Squid Cardioid Stereo mic and a Sony ECMF8 Electret Condenser mic but neither work. I have tried them both with the iRiver firmware and they both work ok although they both work better in the ' ext mic' mode and only seem to have half the volume in 'line in' mode.
I have tried all the formats but none of them work. I really want to use Rockbox for my recording. Can anyone help me?

[petur]

If they work in the original firmware, they must work in Rockbox

Mic power should always be there, and Rockbox gives you the full range of GAIN the hardware offers.

Are you sure you've selected line-in and not s/pdif?

[gramit]

I'm definitely in Line In. I have noticed that when i'm in int mic on Rockbox and in line in, ext mic and int mic in irver firmware the channel meters flash away merrily even in pre recording prior to starting the recording. When i'm in line in on Rockbox there is no action on the channel meters at all either in pre recording nor when I press the record button. Does this throw any light on it ?

[petur]

Does this throw any light on it ?

Nope, it just smashed the lightbulb 

Can you change the gain to +48 or something like that? That should make the peakmeters react on the noise of the electronics (unless you did the CF mod)

Other options:
- did you alter the peakmeter settings?
- did you engage the AGC and have set a max AGC gain?

[gramit]

I stuck another lightbulb in and low & behold there was light !

I put it down to my lack of understanding of sound recording. I had read one of your responses to an earlier post where you said to try and keep the Gain between 0 - 10 dB. I was looking within this range but nothing was happening. I now realise that this is ok if you can adjust the source output to get you within this range but if you are stuck with a fixed source output which is low, it is necessary to increase the gain to both channels to pick up the sound through line-in. I started racing towards the 48 db which you suggested and got as far as 40 db and the peakmeters kicked in.

Thanks Petur for your help on this one!!! One more question if I may......what is the CF mod ?

[Multiplex]

CF Mod is replacing the Hard Disk with a Compact Flash card - for the iRivers you need an adapter - there's an active thread (or two) over in hardware

[petur]

I'll add to the response of Multiplex that the reason I asked is that the CompactFlash gives almost no electrical noise, compared to a (spinning) harddisk. So If there is a harddisk inside your h120 you should see that noise.

If you are needing +40dB to get some signal, I suggest you get a mic pre-amp because your recording will be too noisy. Stay below +20dB if you can.

[gramit]

Thanks for all the info, its been really helpful. I've got a big recording session coming up in a couple of weeks so i'll be able to give it a good test out and then go on from there. I must look into this cf mod......sounds interesting.