Virtual balanced input is disabled when using the Scarlett 2i2

[dlr]

I may be the only one who has used the virtual balanced input as a means to improve measured noise and distortion in an audio interface or amp, but it worked when using the Delta 1010LT, even with the balanced inputs. I suspect that is due to the card having both balanced and unbalanced inputs. REW may be sensing that the 2i2 has no unbalanced inputs, therefore the virtual balanced input option is disabled. What I want to do is use that option in sum mode to combine the two inputs with a splitter sending the same signal to both channels. The sum mode sums the two, then divides by 0.5, exactly what makes it work for the distortion calculations.

Edit: I just found that using the Input Selection Dialog in the RTA will allow setting the Balanced option, but that does not change the option status in Preferences.

And now I see that it has the option for Separate cal for each input. I'll experiment with that, but it took some digging to find that. I had been trying only the Preferences screen. And it still not possible to change the Virtual option from diff to sum.

It would be handy to have an option in the Scope Channel settings screen to call up the Input Selection popup directly.

 

[John Mulcahy]

Virtual balanced is only disabled for mono inputs. Please post a screenshot of your soundcard preferences.

 

[dlr]

Here is a screen shot with as much as I can get into one capture. Note that this is in a new (yesterday) laptop running Windows 11 with the Scarlett ASIO. Previously I was testing on an old Windows 10 PC with the Delta 1010LT. I also was running it with the 1010LT output to ADCiso input with no problems. That, of course, required use of FlexASIO. But I also temporarily ran the 2i2 on the old PC, but quit because the USB port is exceedingly noisy. It never was better than -80.5dBFS and was constant no matter the signal level. I _think_ that I was able to use the virtual balanced option with it, but that was no benefit in that setup. The issue may be related to Windows 11. This is my first system with it.

I have used the 2i2 a fair amount in the past when first working with REW, but I only recently tried the virtual balanced input option.

When using the 1010LT, I checked that the Preferences screen option matched the RTA input option any time it changes.

Also, I don't think that there is an option within the 2i2 software to make it mono.

 

[John Mulcahy]

What REW version are you running?

 

[dlr]

V5.40 Beta 94

 

[John Mulcahy]

Does reloading the ASIO driver make any difference?

 

[dlr]

Does reloading the ASIO driver make any difference?

I haven't tried that, I'll do it now.

 

[dlr]

Bingo! That did it. The option appears in Preferences and the pull down for diff/Sum works now.

Edit:
Thanks, I hadn't thought of trying that. Any idea what might create that issue?

 

[John Mulcahy]

OK, strange. I'll look into it.

 

[dlr]

One more observation. The Measurement Info in the main screen indicates Windows 10 on my W11 PC.

 

[John Mulcahy]

One more observation. The Measurement Info in the main screen indicates Windows 10 on my W11 PC.

Windows 11 still reports itself as Windows 10, but build numbers >= 22000 are actually Windows 11. Getting the build number would require running some native code though so I haven't bothered.