Calibration of the 192...

[gandalf07]

Hello,

At our studio, we upgraded to HD and got 5 brand new 192 (2 of them have an extra 8 ch. analog input for a total of 16 analog input) What a surprise we had when we started to calibrate our 192's, their range are of -22 to -14dBFS... before with our 888/24, we were calibrated at -12dBFS. We have been able to get pass that issue rather easily....

But what we discovered is that the 192's analog input #1 was about 1dB off and we can't correct it. I explain:

We first sent a -20 dbFS 1KHz signal from the signal generator across all analog output and mesured it with a multimeter. Than, using the Calibration Stationnary Pad and the Calibration mode, we send a tone with the signal generator at -20dBFS (our protools pref is set at -20dBFS too) and when patching any analog output which are calibrated into their respective analog input (1 in 1, 2 in 2... etc.), we calibrated the input so that it reads-20.0dBFS and the track stops flashing. But not input 1. We can turn the screw like crazy, it will always go at -21 and higher (higher=-22, etc.) but stops at around -20.8 or -20.7, it doesn't go below that... so of all our 192's input 1 is off less 1dB. Being an input it is less dramatic, but what do you do when you got to record in stereo... yeah use another pair of input is an idea, but what if they are all used?

Does this happened to someone else or am I just being stupid?

Thank you very much...

[privateIQ]

Originally posted by gandalf07:
Hello,

We first sent a -20 dbFS 1KHz signal from the signal generator across all analog output and mesured it with a multimeter. Than, using the Calibration Stationnary Pad and the Calibration mode, we send a tone with the signal generator at -20dBFS (our protools pref is set at -20dBFS too) and when patching any analog output which are calibrated into their respective analog input (1 in 1, 2 in 2... etc.), we calibrated the input so that it reads-20.0dBFS and the track stops flashing. But not input 1. We can turn the screw like crazy, it will always go at -21 and higher (higher=-22, etc.) but stops at around -20.8 or -20.7, it doesn't go below that... so of all our 192's input 1 is off less 1dB. Being an input it is less dramatic, but what do you do when you got to record in stereo... yeah use another pair of input is an idea, but what if they are all used?

Does this happened to someone else or am I just being stupid?

Thank you very much...

<font size="2" face="Verdana, Arial">You're not stupid. The calibration issue (especially between 96 and 192) has been raised in several other threads without response from Digidesign.

As for your particular problem, I'd send one of the I/O boxes back for a bench check. I think we're all praying here that it isn't a manufacturing defect for a whole run of these things.

Best of luck and please let us know what you find out.

PIQ

[gandalf07]

Haha,

Like as if I had time just to unplug a 192, ship it to Digi and wait couple of days... or month maybe, shutting down that particuliar studio just for Digi to check if they did a good job.... and who's going to give me money to pay the bills? Digi?

Seriously, I've only checked 2 192's out of 5... and I'm affraid...

Do you have a link to other treads concerning the calibration of the 192 somewhere? If it's in the forum I'll find it .... thanks...