Topic: A unity gain question / Tascam DR-100 MKII

[jimbee]

A newbie question, any advice much appreciated, I am experimenting with trying to get the lowest noise floor out of the DR-100 MKII while recording regular-volume film dialogue in a room.   My latest attempt is to run a Rode NTG-2 mic into a Behringer mixer, and go line-level into the Tascam.  With the Behringer cranked to max gain, +60, and the Tascam gain wheel at the middle, +5, the dialogue peaks at about -14, and the noise floor is pretty good, down around -51, which is better than if I run the Rode mic directly into the Tascam's preamp on mic level.  In that signal path, with the Tascam gain cranked to max, +10, the noise floor is around -40.  I would like the dialogue level to be slightly louder, but pushing the Tascam gain wheel to +7 gives me a little more noise than I would like.

Am I doing this right?  Is there some magic "unity gain" where the Tascam does not add noise and all the preamp gain is being done by the mixer?  Would +5 on the Tascam gain wheel be near this magic point?  Do you just use your ears to find the best combination of gain on the mixer and gain on the Tascam?  Or is there some kind of "standard" way that you should do the gain staging?

And let's say I subbed a first generation Sound Devices MixPre for the Behringer mixer, (unfortunately, this is not a test I can afford to do), would the noise floor be even lower, on the theory that you get what you  pay for?

[kleiner Rainer]

Hi jimbee,

this is not a "unity gain" (*)  question, but a "signal to noise ratio" question. There is a very interesting table here:

http://www.avisoft.com/recordertests.htm

with recorders sorted for their noise floor. Those guys record animal and nature sound, so they are interested in best S/N performance.

The NTG-2 has a noise output of about -110dBu, so the recorder should be some dB below that to avoid making it worse. In theory, the DR-100 Mk II should be okay with a noise floor of -119dBu at maximum gain. I don`t know whether you use phantom power or battery power on the NTG-2, but it is possible that the DR-100 introduces noise when phantom power is on and the Behringer has a cleaner phantom power supply.

Now the question is: how quiet is the location? The easiest way to improve the S/N ratio is to move the mic as close as possible to the sound source, since in most cases the mic limits the S/N ratio, not the recorder.

BTW the MixPre D would fit into the above mentioned table just below the SD722 (not astonishing considering its pedigree ). I own one and I can recommend it. Money well spent.

Hope that helps.

Greetings,

Rainer

(*) BTW a piece of wire has unity gain, but you can`t record with it. I consider the concept of "unity gain" as used in TS nonsense. Avoid overloading the amplifiers, check for optimum S/N and enjoy...

[kirk97132]

I would NEVER run a Behringer product at MAX anything.