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-   -   Tascam dr-100 (https://www.dvinfo.net/forum/all-things-audio/188991-tascam-dr-100-a.html)

Don Palomaki April 12th, 2009 09:36 AM

Tascam dr-100
 
Just ran a couple quick test on the new TASCAM DR-100 Portabel Digital Recorder.

My point if reference is as a past user of various MiniDISC a recorders and a M-Audio MicroTrack (the original, not the II)

General impressions: I like it.
Controls are easier than on the MicroTRACK or the portable MiniDISC recorders I've used.
Feels much more substantial.
Is a larger package
Key factor: a much better battery/powering options.
(Have not yet tested for battery life or effectiveness/intrusiveness of the internal limiter or AGC)

Looking beyond the published specifications
Noise floor at XLR inputs and max record gain settings is -71 dB below sine wave clipping level.

~1.9 mv from a 200 ohm source impedance input results in a record level about -13 dB relative to peak sine wave record level.

Low frequency roll-off is well below 20 Hz. High frequency cut-off is as determined by sampling the frequency.

John Newell April 12th, 2009 12:44 PM

I'm going to be interested in seeing how it compares to the Sony PCM D50.

Dan Brockett April 12th, 2009 03:36 PM

Don:

Besides specs, what do your ears tell you when you monitor XLR inputs with a mic and good headphones? Have heard that this unit does not produce the quietest audio when using balanced mics and I would love to read about what you are hearing.

Thanks,

Dan Brockett

Don Palomaki April 15th, 2009 04:40 AM

So far no obvious issues with unacceptably high noise in the few brief recordings I've had a chance to try. I've tried a Shure Beta 58, Shure BG4.0, and Rode NTG2 microphones (on AA battery power as appropriate), using MDR-V600 headphones. But these were not critical listening tests, just checks to see if it was working.

Dan Brockett April 15th, 2009 12:07 PM

It would be interesting to sit in a quiet room with headphones and a good condenser mic and see if this unit has as much hiss in the mic pre-amps as others have suggested in testing the DR-100.

Dan

Don Palomaki April 16th, 2009 05:00 AM

The mic preamp noise level (with preamps at highest gain setting and input terminated with a 200 ohm metal film resistor)) was 71 dB below maximum sine wave record level (74 dB below max square wave record level) based on the recorded .WAV file on the SD card.

I wonder how much of the hiss they report was from the headphone preamps, or from the self-noise of the condenser mic (which can be substantial depending on the specific mic used), or even room noise that the mic picked up? Can you give me a pointer to the tests?

Of course the DR-100 is a piece of moderately priced field recording gear and will not match studio preamp or recorder performance.

Mike Demmers April 16th, 2009 12:36 PM

No conclusions can be made without knowing the gain of the mic preamp.

With only slight changes in your tests, it should be possible to figure out something pretty close to approximating the actual Equivalent Input Noise of the preamp, which should put the question to rest.

See:

Equivalent Input Noise (EIN)

Audio Specifications

Don't worry about bandlimiting.

-Mike

Mark Boyer April 16th, 2009 01:40 PM

My big question is about power. I previously owned a Microtrack and the rechargeable batteries were always an issue. I now have moved up to a Fostex FR2-LE and the batteries last all day. The Tascam has a rechargeable Lithium battery and also 2 AA cells. What type of recording time do you get with the unit? My other issue with the Microtrack was a lack of XLR connections and I preferred the Fostex controls being on top when carried by the strap. The Tascam volume controls are on its side.

Don Palomaki April 16th, 2009 07:54 PM

A simplified analysis follows, and for talking purposes impedance will be ignored - in this case they would make a minor difference.

The DR-100 spec states that at the GAIN HIGH setting -42 dBu is the maximum level input. This corresponds to maximum allowable digital record level, and -58 dBu corresponds to "standard input level" (which to me implies 16dB head room).

0 dBu corresponds to 0.775 volts RMS.
Peak record level corresponds to -42 dBu input, and
Standard input level corresponds to -58 dBu per the manual.
I measured the noise floor with no input signal, input terminated by 200 ohms, as -71 dB below maximum record level.
Thus the equivalent noise input would be -113 dBu.
The .WAV file was at the 48 kHz sample rate, which limits the bandwidth to about 22 kHz.

The mentioned AT-897 microphone has an open circuit output of -40 dBV at 1 Pa.
It has a S/N rating of -77 dB at 1 Pa
Thus it has an equivalent noise output of about -117 dBV
But note one is in dBV and the other is dBu - different reference levels.

To convert dBu to dBV subtract 2.2 dB
So the noise floor of the DR-100 at maximum gain is about -115.2 dBV or about 1.8 dB higher than the noise output of the AT-897.

However, if you look at another common video microphone's specification, the Azden SGM-1X, it has a rated output of -41 dBV and a S/N of 65 dB, so its noise output would be on the order of -106 dB, about 9 dB higher than the DR-100.

Now here is the issue. The rated output of the AT0897 at 1 PA sound pressure level is just about clipping on the DR-100 at max gain, so it may not be use at that gain level for many applications. In summary, you have to assess how it fits your uses and noise budget.

As to battery life, I have not tested that, but the Li-Ion can be change by the user, and an Alkaline or Ni-MH AA can be use in conjunction with the Li Ion for more run time. The nominal rating is 5 hours record time for 128 kbps mp3 recording with the Li-Ion, 4 hrs with Ni-HM, and 2 hours with Alkaline. The Li-Ion battery can be charged from a USB port or an A/C adapter.

The DR-100 has XLR inputs and 48 volt phantom power.


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