Tools advice for 192 I/O calibration

[Loudyman]

Hey guys,
I want to calibrate my recording chain and I wonder which tools I need for this purpose ?
I know that in the 192's manual , digi recommend to connect an external VU meter and align the outputs to read "0 VU" on it (while sending a signal with the desired calibration level)....

But, my question is :
As I don't have any mixing console ,just preamps and an incoming monitor controller , how can I calibrate the 192 ?

-With an AC voltmeter and use the old calibration method ?
If so, could you tell me which one to use please ? (reference or things I should know on them are welcome as I know nothing on this kind of instrument )

or
-Buy a VU meter only for calibration ? (this one seems to be a nonsense in this case )

or something else ?

Thanks in advance.

[Rail Jon Rogut]

http://duc.digidesign.com/showthread...ke#post1451169

Rail

[Sean Russell]

That's a bit more convoluted then it needs to be.

Get a small screwdriver, and a DB-25 -> DB-25 cable.

I usually un-rack the 192, and get it so I can see the mix window and the 192 in front of me.

Plug in Digi-Link and Power to the unit, and connect the DB25 output to input on the card you want to cal, and put PT in the cal mode..

I use the Digi Template for the 192 cal and sometimes have to change the -18 to -14 (in rooms that have a 96 i/o and/or 1622 in addition to the 192).

The rest should be as is...

HTH!

[TVPostSound]

Plug in Digi-Link and Power to the unit, and connect the DB25 output to input on the card you want to cal, and put PT in the cal mode..

BAD advice, you can not calibrate the output to input.
You calibrate the input with a calibrated output.


Do not use a VU meter to calibrate unless you know the VU meter has been calibrated first

To the OP, use a voltmeter, 1.228 VRMS across pins 2 and 3. Using the signal generator at the operating level you choose, then you can calibrate the input using the calibrated outputs. At that point you can then calibrate your VU meter.

[TCDet]

"You calibrate the input with a calibrated output."
Yes outputs first (Just like Tape but with a few less tweaks n tones)

I bring a spare video monitor (in order to see ProTools) to the back of my rack. My meter of choice is a calibrated Fluke 867B.
(There are other (Many) choices for no load RMS meters)
Calibrate your outputs (I use RMS 1KHz at -18 DBfs Work dependent)

If unsure then hire a tech you feel comfortable with.

After checking / or re-cal I usually check my Audio Monitor calibration. Same tones for voltage to amps (all PB muted) then Pink Noise for SPL levels.

I would generally do all the above after a change to my control room environment or any new changes to my monitor chain.

From there a rough check every now and then off the patch panel.

Once all is done.......

[Loudyman]

Thanks for the replies ,

As I also need an SPL meter to complement my ETF software for room measurement, do you think that a box like the Phonic paa3 will do it ? or it's a toy ?

It does SPL, dBu, Voltage, Rta, rt60 measurements ....

And I'll use it for the 192 I/O calibration as well .

I ask this cos' I can't find a good SPL meter and the "classic" Radioshack that everyone seem to use is not available in France ...
This way I kill two birds with one stone.

Any thought ?
Loudy;

[Loudyman]

Then, no opinion on the Phonic Paa3 ?