ARTA

This is what I get from my portable system.

Peter
 

Attachments

  • M-Audio Transit jitter test at 48KHz.png
    M-Audio Transit jitter test at 48KHz.png
    27.5 KB · Views: 355
"What window function did you use?"

Hi SY,

Sorry, I should have said. I copied your settings except that the Transit only operates up to 48KHz in ARTA. I didn't save the original measurement, so I re-did the test as shown attached via a print screen capture.

Peter
 

Attachments

  • M-Audio Transit jitter test at 48KHz_2.png
    M-Audio Transit jitter test at 48KHz_2.png
    136.2 KB · Views: 352
Peter,

I'm interested in your ARTA Transit calibration settings. How did you arrive at 2710.95 for line-in sensitivity? That corresponds to 1.9VRMS, which is well above the ADC clipping point of the Transit. (For reference, I use 1920.00 on mine.)

Cheers,

Dave.
 
The main issue with the 2i2 is that the performance is poor if you drive single ended from it. I have as one of my things to do, to make a differential to single ended buffer to use when doing measurements of SE stuff (which is pretty much everything I have 🙄)

Tony.
 
Distortion goes through the roof.... noise floor may also suffer but I can't remember.

It doesn't have dedicated se outputs. You just put in a tr plug instead of a trs and it suffers.

edit: attached some measurements I did a while back... 3rd harmonic in the balanced isn't fantastic either, but I guess a notch in the buffer I'm thinking about might help there...

Tony.
 

Attachments

  • balanced.png
    balanced.png
    22.4 KB · Views: 373
  • unbalanced.png
    unbalanced.png
    22.4 KB · Views: 317
Last edited:
It's always a good idea to check 1/4" outputs with a 3-conductor plug to verify if there's signal on the (-) output. If so, I make it a habit to never short out that signal.
Thanks for the link to the FocusRite modification.

Dave.
 
^ Yes, and I might look at doing something a little different with the output using a trs plug and then a resistor to ground for the ring to sleeve connection to see if that helps. but the 2i2 manual clearly states that either balanced or unbalanced 1/4 inch plugs may be used 🙂

Tony.
 

Attachments

  • 2i2_outputs.png
    2i2_outputs.png
    65.8 KB · Views: 283
Peter,

I'm interested in your ARTA Transit calibration settings. How did you arrive at 2710.95 for line-in sensitivity? That corresponds to 1.9VRMS, which is well above the ADC clipping point of the Transit. (For reference, I use 1920.00 on mine.)

Cheers,

Dave.

Hi Davey,

I'm not sure where that 2710.95mVpk line-input sensitivity came from. I suspect that it came from one of my other USB sound cards such as my E-MU 0202. As it turns out it does not seem to matter, because when I go through the cal procedure for the Transit and re-test the jitter, it gives the same performance as before. I suspect that if Ivo outputs a -10dBFS (for example) he will be able to check the level that appears at the ADC output on a loop test and adjusts the levels accordingly, but I have no proof of this of course, just my guess as to what he does in software.

Peter