ARTA

[Pano]

Yes Gary, that's what I'd like to know. Seems this test may be swamped by noise on lesser cards.

 

[vacuphile]

I got the same picket fence on my cardbus version of the 1616m, and, in tune with the choir, what does it show us?

 

[SY]

When I get back from this trip, I'll try the same test on a few other units and see what we get.

 

[PLB]

This is what I get from my portable system.

Peter

 

[SY]

What window function did you use?

 

[PLB]

"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

 

[SY]

Kaiser 7, thanks!

 

[SY]

Same test conditions as yours but using the Focusrite Scarlett 2i2.

 

[Davey]

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.

 

[wintermute]

Same test conditions as yours but using the Focusrite Scarlett 2i2.

I've missed the post about how this test is done and what it means... since that is my soundcard, I'm interested in whether that's good, bad or indifferent Also saves me doing the test myself

Tony.

 

[Pano]

So despite all the griping about the Focusrite, it looks very clean indeed.

I noticed you are using 130K bins. Crickey! How long does that take to settle and how many averages are you running?

 

[wintermute]

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.

 

[Pano]

What goes wonky with the FocusRight in SE mode?

 

[wintermute]

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.

 

[AKN]

Focusrite Scarlett 2i2

Hi,

See schematic shown here (scroll down), if accurate. Output op-amp loading gets severe if unbalanced trs is plugged in.

 

[wintermute]

Thanks Anders! I'm a bit surprised at the output not being dual rail. I guess built down to a cost. Certainly having 1/2 the opamp driving effectively a 47 ohm load probably messes thing up a bit!

Tony.

 

[Davey]

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.

 

[wintermute]

^ 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.

 

[PLB]

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

 

[Carl_Huff]

Has anyone here tested the M-Audio M Track Plus II?? M-Audio - M-Track Plus II

M-Audio has been bought and sold a couple of times over the last few years. I wonder if the quality of their current stuff is as good as their older products.