H300 Rockbox Lack of Ext Mic Recording

[Gabahey]

Hi! I have a H320 with RockBox with a Sony ECM-MS907 (Stereo Mic, It wonderfull).
I have this problem: The signal for Ext. Mic recording is too low in RB.(maybe because its made for Line In and not for Ext Mic). Its much louder when I record with Iriver Firmware, but It hasn´t recording Vu meter, as RB has.
It´s obviously not a matter of hardware, but a problem of Soft.
RockBox lacks of an External Mic option for recording.

Anybody has a solution for this? Either in RB or in Iriver Fw?

Thank you very much!!!

Gabahey

[PaulJam]

Have you already tried to increase the gain setting in the recording screen?

[Gabahey]

Yes, the gain was in maximimum. But the signal was really poor. I used this mic to rec with my MD and it was awsome. Probably the MD had a Preamp. But still I find the signal too low. A portable recorder should be prepared to allow you to record without a preamp.
Well, if anybody has experience in recording with External Mic, please tell us your experience so we can learn.
Probably there is another firmware wich has more input power for External Mic Recording.
Thank you very much to all!!!

[Frosti]

I always thought that maximum gain at the RB firmware would show similar characteristics as the stock FW, try doing some new recording tests!

[PeteSwensson]

My experience with recording on my iRiver H340 has been that recording from an external mic gives a small signal, with a fairly high level of noise (background hiss), no matter what mic you use. Increasing the level of gain through the iRiver software just gives a larger signal with more prominent noise. I concluded that the iRiver doesn't have much of a pre-amp, so I use an external pre-amp to boost the signal up to where I want it.

I get the same response whether on the original firmware, or on RockBox.

There are not many options for portable external battery-powered pre-amps. I use one from Sound Professionals, a firm in New Jersey, USA, that sells on the web.

I really like my iRiver, and am happy with the quality of its recording when you give it a good signal. I recognize that it is a digital player first, and a digital recorder second, so that is why I have augmented its recording abilities with a pre-amp.

[Gabahey]

Thanks to all! You are right. The input Rec signal is the same in both firmwares. Its also true that my MD had a preamp and H320 hasn´t.

Pete, thanks for your recommendation. Could you tell me which Preamp you bough exactly?
I saw this one, which seems very good for this (its a Mic with preamp):

Microphones, USB Microphones, Preamplifiers, Digital Recorders, Cables and more at Rock Bottom Prices from The Sound Professionals - Great deals on Microphone, Preamplifier, Digital Recorder, Cable and more!

anyway I´m still not sure what to do with my h320. I bought it refurbished, and it works strange some times, specially when I connect it Usb. It tilts sometimes and some audio files have troubles when I play them. (they jump in the middle of the track to next track). Strange!

Thanks everybody for your comments,

[PeteSwensson]

I have tried two different pre-amps: 1) the Rolls MP13 Mini Mono microphone pre-amp, and 2) the Sound Professionals SP-Preamp-9. The product you have found was not available when I was shopping, or I probably would have considered it.

My comments on each:

1) The Rolls MP13 was my initial choice, and I used it for two years. It runs on wall power with an adapter, so to use it in the field I had to solder together my own battery pack using AA rechargeables and battery holders from Radio Shack. That was a bit crude, but quite effective. I was recording guitar classes at music camp, so I didn't need stereo.

2) I have since bought the SP-Preamp-9 and a stereo mic. This pre-amp is stereo, and it provides a convenient case for recorder and pre-amp, so that there is less hassle from fewer dangling parts (can you picture my previous set-up: dangling mic on mic stand, dangling battery pack, dangling pre-amp, and recorder). It also seems to have a pretty good amplifier, with very low noise, and gain control for each channel. You won't want to adjust the gain during recording, however, since moving the sliders introduces a hissing noise while they are being moved.

3) The photo of the SP-Booster-1 seems to show it attached to the recorder. You won't want to do this unless your recorder has flash memory instead of a hard drive. Every time the hard drive spins up, you get a big, irritating whine added to your sound track. Get a separate mic stand like the one shown, or the more portable SP-DTS-9 with its flexible tripod legs. You'll need to figure out mount/connector details -- I don't know what kind of mount/connector the SP-Booster-1 uses.

By the way, I have 3 irivers, two of which are modified models: H360 (nee H340), H308, and H320. Since the H308 CF mod was successful, I plan to make the H320 into an H332. With the CF mod, it is possible to record from an iriver's internal mic without worrying about hard drive noise. The iriver original firmware will not accept CF in place of a hard drive, so you have to install Rockbox. But that's a whole other discussion thread.

[idivorceyou]

I have a ton of great experience recording into my Rockbox'd H320 for years now.
I use a variation of this mic: "T" Style Stereo Mike for MiniDisc
no pre amp, just right into "mic in", adjust the gain, and super high quality live recording of my band, rock concerts, etc.
the variations I made on that mic design are to keep the headphone line long, add an aligator clip, place the mic elements both facing forward, shorten the mic to about 3-4".
why buy a mic when you can build a great one for about $5-$10??