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Re: Re: 722 vs PMD670

Subject: Re: Re: 722 vs PMD670
From: Klas Strandberg <>
Date: Mon, 20 Jun 2005 14:59:20 +0200
Yes, it is a surprise.

Let me take my "logics" all over again. If I'm wrong, I am.

All condensor mic's have their internal mic preamps. This internal preamp, 
in combination with the membrane and other acoustical processes, can be 
very noisy or very quiet. Or somewhere in between. This is best expressed 
by the (dbA) figures, for example. The figure "sensitivity -xx db" is 
unreliable, as some manufacturers feel free to use their own reference level.

If the output (mv/pa) from this microphone is low, then you need a lot of 
recorder micamp gain. If the recorder micamp is poor, then you will hear a 
lot of noise.

But if the output of a microphone is high enough, all noise you will hear 
is from the microphone and it's internal electronics. Not from the recorder 

Such a high-output microphone will cause distortion if you blow the trumpet 
into it. But for the nature sound recordist it will work fine.

I thought that the Telinga output was high enough to override any recorder 
micamp noise. All tests I have done, with cheap MD's and Dat's etc have 
proven this. I always hear mic noise, not recorder micamp noise.

Then comes Martyn and proves something else: At least when used with the 
PMD670, the Telinga output is not high enough. Therefore, he has to turn up 
the PMD gain so much that it is the PMD micamp noise which can be heard.
When he uses the 722, noise cannot be heard.  Because it is a better micamp.

 From my point of view, the PMD mic input amp must be terribly bad. I don't 
understand that. It is noisier than all cheap MD:s, noisier than Edirol R1 
and all likewise.
Why?? There is no reason, except that Marantz might have thought that 
"nobody cares anyway, all the kids are recording pop-music anyway" -, it doesn't make sense.

Or, is something wrong with Martyn's PMD?
Un-clean phantom power?
Digital noise?


At 07:29 2005-06-20, you wrote:
>It's no surprise that the 722's recording is cleaner and quieter than
>the PMD670's.  After all, the 722 costs three times as much, can
>digitize at 24/192 (vs 16/48 on the PMD670), and claims a preamp noise
>floor of -130 dB (vs -65 dB).  It would be news if the 722 *didn't*
>sound cleaner.
>Martyn's recording helps us undestand how these technical advantages
>translate into performance in the field.  Thanks!
>"Microphones are not ears,
>Loudspeakers are not birds,
>A listening room is not nature."
>Klas Strandberg
>Yahoo! Groups Links

Telinga Microphones, Botarbo,
S-748 96 Tobo, Sweden.
Phone & fax int + 295 310 01


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