Sound wrestling

[catsittingstill]

Okay, now I'm puzzled. Are there any audiophile/Mac geeks out there who want to help me with this?


I've got a Sharp MD-MT15 Minidisc recorder. I want to take the stuff I've recorded on minidiscs and move it into my computer (a white Mac iBook running OSX.1) to post as mp3s (birdsong, waterfall noises, whatever) or to burn to CDs (personal copy of "best of housefilk collection", that kind of thing).

I've got a Griffin iMic that will connect a microphone to a USB port, and I can record (using the Audiocorder shareware program) from the mic just fine. Well, there's a little bit of a hum, which is suboptimal, but the sound is recognizable. I bought a patch cord (male-to-male with 1/8 inch jacks), and I can pipe the output from the headphone port of my CD player into my computer and record it and it comes out about like the microphone.

But when I try to use the same cord, same setup, to pipe the output from the headphone jack of the minidisc recorder into my computer all I can record is buzzes. They come in a vocal rhythm--sort of like a wasp's nest trying to talk--but it's largely unintelligible.

Does anybody know why the output from the CD player works and the output from the Minidisc player doesn't? They both run headphones about the same. Does anyone have any helpful suggestions? Is it just impossible to do this at all?


Much bike riding today. Rode into Jefferson City (where Kip works, a journey of about 4 miles), went to the bank, went to Radio Shack and Wal-Mart--and couldn't help but notice that *none* of these places have a bike rack. Grump. At Radio Shack I had to take my bike around to the alley behind the building and lock it to the gas meter. Which worked, but it makes me nervous to have my bike out of view like that--thieves like messing around in places nobody can see them.

Comments

[randwolf.livejournal.com]

Damn. I'm sorry--I think I gave you a bum steer. I think you're experiencing the audio equivalent of pixellation; the minidisc recorder probably has ultrasonic noise in its output and relies on the headphones to filter it out. When you hook it up to the iMic, it confuses the iMic's digitization hardware. CD players don't usually do that. Solution is a low-pass filter with a "knee" in its response at about 44 kHz--essentially the same filter that's found at the analog output of every CD player. Problem is, it's a nuisance to build the things and I'm sure they're moderately spendy. Any experts here have sources for them, or simple designs?

[mrlogic.livejournal.com]

I haven't had problems transferring MD audio to my Mac, but my setup is quite different: I have a G4 Mac with an aftermarket audio card for digital recording. I run the headphone output of the MD player to an external mixer, and then run the line output of the mixer to the audio card. It works fine and is virtually noise free.

I haven't ever tried it with an iMic and I'm not sure what sort of levels an iMic can handle. You might want to try running the MD output through your home stereo system and see if you can get the line-level output from that to go comfortably through the iMic.

Good luck,

--blake

[catsittingstill.livejournal.com]

Thanks Blake! I appreciate the tip. Unfortunately my home sterio system is a 20$ boombox; I'll turn it upside down and look at the back and see if I can find line in and line out jacks, but I have some doubts.

I like the idea of a mixer--I'd like to do my own recording someday, which is part of why I was attracted to the minidisc player in the first place; I had hopes of recording things like campfires and birdsong and waterfalls to use as sound effects for various songs. But the mixers I've looked at have all been in the hundreds-if-not-thousands-of-dollars range and I just can't afford that for a while. Sigh.

Yours--Cat