greenmachine

DC, an alternating voltage would be audible and useless for constantly polarizing the plates.

If you manage to get a pure noise profile (same equipment, same settings, same location etc.), you can try to substract that from the original recording (open both files, invert the pure noise, match it to the original recording and mixdown). I'm not familiar enough with Audacity to tell you how to do it in detail, but it should be possible. Using a battery box most propably won't help to avoid noise. Recording without ac power seems to be your best bet.

This UK located seller has some brand new 1st gen HiMD units for sale, currently: - 19x NH600 for £48,90 each - 20x NH700 for £69,90 each -- 3x NH900 for £97,90 each ...plus shipping costs. Pretty good prices if you ask me.

Is it a 50/60 Hz hum or broadband noise? Hum would be pretty easy to filter, whereas broadband noise wouldn't. Do you have a short sample?

Higher quality AD-DA converters - in theory at least. But even nowadays portables can sound pretty decent when connected to a hifi. The output volume is usually a bit lower, but i doubt many could her a significant quality difference unless using high end equipment and listening carefully.

I wouldn't use any lossless compression method for listening in a portable device anyway since you can have virtually transparant files at approx. 1/5 - 1/4 the size (160-200 vs. 600-900kbps). It would just take too much space and eat batteries without offering a significant gain in quality. Ogg support would be nice, but not really necessary (for me). Maybe they should fix the crippled mp3 playback first.

I wonder if we can ever get rid of these "mp3 is generally crap" prejudices. Mp3 - like all lossy audio compression formats - can be very low quality or - on the other end - virtually transparent (indistinguishable from the original) depending on the bitrate, encoder and settings you use. Actually from own and public listening tests, i'd say it can reach transparency at even lower average bitrates than SP (292kbps). And yes, i often use (high bitrate vbr) mp3 for listening through my hifi (which is propably above average quality). Please refrain from generalisations like these until you can back them up with (blind) listening tests.

analog -> wav -> 160kbps mp2 -> wav -> 64kbps atrac3+ -> wav -> 132kbps atrac3 -> wav -> 292kbps atrac -> wav -> analog = too many conversions, hi-lp propably being the major weak point.

The shorter and more common your username is, the more spam you'll receive. Also, don't give the address to anyone. Use non machine readable display methods (your address displayed in a picture for example) on public sites instead of direct links. I have a (gmail) account which is spam-free for over 9 months now.

*original post edited for better compatibility

1)and 2) It's not necessary to have separate microphones for different purposes if they are high enough quality. Speech is propably the least demanding for recording. Virtually any mic will do. If you want to focus on the voice and reduce the amount of room reverberations on your recording (for whatever reason), you'll need to move close to the source and/or need a mic with cardioid pattern. Music and other complex noises will sound most natural with omnidirectional stereo mics which can be separated to the width of the distance of your ears. 3) High frequencies might get (slightly) attenuated when using (prepolarized) condenser mics in a wet climate, humidity can settle temporarily on the very light diaphragm (condensation) and make it heavier. I don't think there will be long term effects though. Better a mic that is slightly disabled under certain extreme conditions than a dynamic mic that sounds bad all the time. That said, i think the effects would be barely noticable even in a wet climate. 4) Non-prepolarized condenser mics need Phantom power of usually 48V, the voltage of a battery module would be too low. You'd need an external phantom power supply.

What about formatting via the unit? Does it work? What about other discs?

Actually i prefer standarized NiMH over expensive, proprietary li-ion. Fat, read more about battery chemistries here: http://www.batteryuniversity.com/

http://forums.minidisc.org/index.php?showtopic=14408 http://ravn.net/md/hi-mdcal.htm (i searched for "md calculator")

Sorry, i should have done it in the first place. I don't know what model you use, but on my NH700 you have to press the "navi/menu" button for approx. 2 seconds, choose "edit" -> "format". This will erase all information on the disc and you have to refill it from scratch. There's also an "initialize" function somewhere in Sonicstage, which works basically the same way.

Sounds like the system file's messed up. Try formatting the disc.

Maybe this method works for you, but soundquality-wise it's propably not the best for everyone. Most (if not all) CDs have been normalized before being published. If you raise the gain further without applying some form of dynamic compression, you'll risk introducing clipping. If you apply dynamic compression, you'll decrease the original dynamics. Introducing a lossy psychoacoustic compression scheme won't be beneficial for the sound quality either. You could simply use the volume control of your stereo to raise the volume instead in order not to do more damage than good.

I feel the same way. My NH700 does what it's supposed to do (portable high quality recording) perfectly well. I can't be bothered to upgrade anytime soon unless there will be major improvements (unlikely). For portable playback i prefer solid state devices.

It doesn't really matter much if you encode directly from an uncompressed file (pcm) or a high resolution/bitrate compressed file (eg. 256kbps mp3) to a low resolution/bitrate file (eg. 64kbps atrac3+), the resulting quality will be almost identical (low in both cases). The degradation will be most obvious when transcoding a lossy file to a different lossy codec at approx. the same resolution/bitrate (eg. 128kbps mp3 to lp2).

Don't most soundcards have mono mic inputs?

Do as you please, we'll find it anyway.

1) You have to differ between mics that need to be powered [pre-polarized condenser a.k.a. electret (usually require voltages between 1.5 and 10V, suited for MD recording) or traditional non-pre-polarizd concondenser (usually require ~48V phantom power, can't be powered by the MD rec's bias voltage)] and mics that don't need to be powered (dynamic type). The pre-polarized condenser (electret), which requires a relatively low voltage and current, is the most common type nowadays. The sound quality is usually significantly higher compared to non-powered (dynamic) microphones, without a bias voltage they won't output any usable signal though.

A battery module does not preamplify in any way, it just provides the necessary power to the mics, which is absent at the line-in. The line-in does not preamplify, so it can accept much higher input levels without clipping. Use the mic-in for recording quiet to medium, the line-in for high to very high sound pressure levels. The point about battery life extension of the recorder when using external power for the mics is a sheer lie (or too insignificant to be noticable) by the way.

Also it depends on the quality of the mp3s. It wouldn't make much sense to transcode 64kbps mp3s to 192 kbps Atrac3+. For best quality at your bitrate of choice, it is best to begin with a lossless file (i.e. CD) whenever possible instead of transcoding from a lossy file. Car stereo's ain't usually that demanding though. Or get a mp3 player and you won't have to think about transcoding, bitrates, etc.

Could be the mic-/headphone jack or even the headphone itself. How do you know it's not the microphone? Do you get sound on both channels when listening to a prerecorded MD? Does the meter show levels on both sides while recording?