600Ω microphone OK?

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Level 5

6,810 points

600Ω microphone OK?

I have an elderly Technics RP-3215E microphone which has an impedance of 600Ω.

Will this give satisfactory performance on my G4 PB? I will need to get an adaptor before use so would prefer to find out before starting to unearth one.

G4 733 1.5GB, PB G4 1.67 15" 512MB, Mac OS X (10.4.11)

Posted on Jul 9, 2010 2:27 PM

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Answer 1

louie

Level 4

2,950 points

Jul 9, 2010 10:58 PM in response to Michael Wasley

600 ohm is fine, but from what I can find out about this microphone, it's a stereo electret condensor from the 1980s. You'll probably need a penlight cell to power it, and more importantly, a stereo microphone preamplifier to boost this microphone's output up to the "line level" that the Powerbook input jack requires.

If you try to simply use a cabling adapter, you will likely get very low signal through the Powerbook, but the impedance is not the problem.

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Answer 2

Michael Wasley Author

Level 5

6,810 points

Jul 10, 2010 12:56 AM in response to louie

Thanks for response.

The mike is as you describe and uses an AA battery.

When I last used it many years ago it was connected via its two (L/R) large jack plugs to the sockets on a NAD 6150C tapedeck. Please can you tell me if that additional information confirms your views on signal level?

I'm thinking of recording small grandson's noises for posterity. If signal level is low would subsequent amplification in Audacity give reasonable results or would I need to be looking for a new mike?

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Answer 3

Michael Wasley Author

Level 5

6,810 points

Jul 10, 2010 6:54 AM in response to louie

I suddenly realised that I had adaptors that would let me connect one channel to the Mac. Result, as you predicted, very low level. Speech directly into the mike and recorded in Audacity then amplified (40dB!) showed a lot of hiss which noise removal tidied up nicely to produce quite an acceptable result. However for more general room speech it was a useless signal level.

One solution would be to use the old NAD tapedeck to generate a line signal for the Mac. That would work for static situations but is not practical for what I want.

So presumably the solution is a dynamic microphone to line in. Is that correct? (I'm discounting USB as I understand it can cause problems for input to Audacity.)

Any particular issues to look for when selecting a mike?

Any suggestions for a cheap model that will be adequate for the intended light use of recording infant prattle?

Thanks.

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Answer 4

louie

Level 4

2,950 points

Jul 10, 2010 10:23 AM in response to Michael Wasley

Yes, you see the problem.
No, a dynamic microphone will have a similar level. What you need is either a stereo microphone preamplifier for your mike, or a new microphone that has a preamplifier built-in, so effectively has the stronger line-level output the Mac requires.

I would need to look around to see what may be available. Prices, as usual, could range from perhaps $20USD to hundreds. Quality is a bit limited by using the built-in audio, but is adequate. Professionals would use a Firewire or USB audio interface box instead of the Mac audio input.

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Answer 5

louie

Level 4

2,950 points

Jul 10, 2010 6:26 PM in response to louie

I tried looking the web, but found no good products that do what you want at low price. Maplins has a preamplifier, but uses a mains power pack, so would function in a manner as using the old cassette deck.

It would appear the standard answer in this situation is the Griffin iMic, but it is USB.
http://www.griffintechnology.com/products/imic

You might consider buying a handheld audio recorder such as a Tascam, Sony or Olympus, then transferring the audio files into the computer for editing and storage. Many of these recorders are quite good, for about $200-400 USD.

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Answer 6

Michael Wasley Author

Level 5

6,810 points

Jul 11, 2010 3:50 AM in response to louie

Many thanks for further help and interest.

I've unearthed the old NAD tapedeck which will get me away although as it weighs a ton it's not exactly a portable set up. Initial trials produced an intrusive buzz; not certain where it was coming from as moving things around etc didn't do much but it then disappeared and I can't recreate it so still don't know what the cause was.

I had wondered about the iMic but have read very mixed reports about it, especially with microphones.

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Answer 7

eww

Level 9

53,052 points

Jul 11, 2010 5:57 AM in response to Michael Wasley

Michael: If the alternative is to lug around an old tape deck or some other device that keeps you tethered to a wall outlet, I encourage you to give the iMic a try. I've never used mine with a microphone, but I did digitize all my old tape cassettes and some vinyl records through it with very satisfactory results. And at $30-$40, its price is pretty low for the flexibility and portability it would give you. If it doesn't work out for your purposes, just sell it or give it away.

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