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Gear / Technical Help => Recording Gear => Topic started by: scottwu on November 14, 2008, 11:14:19 AM

Title: Annoying idle tones on Fostex FR2LE?
Post by: scottwu on November 14, 2008, 11:14:19 AM
I thought they just was typical computer screen pickup, etc. But I took my setup out about 3 miles off shore for some nature recording and I still got them. They are all >15K Hz and never cause any audible artifacts. In searching I found them mentioned on a British nature recording site with a big ???.
Title: Re: Annoying idle tones on Fostex FR2LE?
Post by: page on November 15, 2008, 12:47:59 PM
sampling rate recording at?

I've seen a (~500hz long) spike up in the 35khz range when I record at eiher 88.2 or 96 (stock or modded). Not sure if thats what your refering to.
Title: Re: Annoying idle tones on Fostex FR2LE?
Post by: scottwu on November 15, 2008, 02:18:44 PM
Yea, I was doing 24/96 so it looks like they are there. I wonder if it's chip set or layout/shielding related.
Title: Re: Annoying idle tones on Fostex FR2LE?
Post by: DSatz on November 17, 2008, 07:02:11 PM
scott, were you using the unit's analog inputs? Mike or line level? (I have no solution to offer; I'm just trying to find out when this problem might tend to occur.)

--best regards
Title: Re: Annoying idle tones on Fostex FR2LE?
Post by: scottwu on November 17, 2008, 07:26:01 PM
I was using unbalanced in on the XLR connectors. I have my own mics that are low impedance unbalanced out with an external battery box. I got the same result with a Rode NT01A BTW w/wo an external P48. Someone said the problem was only with the internal P48 but I find random low level tones that are different for different sample rates almost all the time. I also notice that changing the mic position moves the amplitude around, so there is some kind of coupling definately a tough nut to crack. The fact that a few others see this makes me feel that it's not just me, and anyway I don't hear any artifacts in the recordings. I got some very nice recordings at the Omega Institute in upstate NY of wild turkeys.
Title: Re: Annoying idle tones on Fostex FR2LE?
Post by: page on November 18, 2008, 04:10:15 PM
I've seen it on the  TRS 1/4" as well. I think it's on my samples the Will is hosting for the T-Mod test.
Title: Re: Annoying idle tones on Fostex FR2LE?
Post by: tonfunk on July 12, 2018, 05:54:07 PM
Hi folks,

sorry for resurrecting a fairly old topic, but unfortunately this was the thread coming as close as possible to the issue I have with (used) Fostex FR2LE I bought recently.
Mine shows audible, periodic noise, especially (but not exclusively) with high gain settings.

Maybe someone in the forum remembers if there is a cure for the potentially clock related issues on this device.

Attached you can find an audio sample with the 'characteristic' chip chip chip chip chip....

BR