The EMU has bal input but SE-output. On the pcb I discovered additional op-amps delivering the balanced signal. So I connected the left channel to an additional TRS jack for a fully balanced signal chain.
Also what i guessed about the input/output !
Do you recall, how excatly you connect your's ? - Cablesize / quality, lenght, XLR connection on pin 1,2 & 3, TR orTRS plug on output
Jesper.
XLR pin1=- pin2=+ pin3=gndAlso what i guessed about the input/output !
Do you recall, how excatly you connect your's ? - Cablesize / quality, lenght, XLR connection on pin 1,2 & 3, TR orTRS plug on output
Jesper.
As I said, I've modified mine to bypass front panel connectors and installed TRS on the rear. XLR only make sense for balanced mic otherwise use standard TRS. For loop measurements of the soundcard I don't recall any issues using an ordinary interconnect from input to output. But for measuring amps I always used it together with Pete Millett's interface which provides isolation.
Connection from soundcard out to amp in is via shielded cable and a passive attenuator (10k poti). Balanced or unbalanced. And this is the route for the one and only GND connection between both. The return path is balanced - you will need this anyway measuring bridge output of class d-amps. There is another attenuator in between. This cable is shielded as well, but shield is connected exclusively to soundcard gnd to break any gnd loop. In case of a single ended tube output the input- is tied to amp gnd, input+ to amp out hot.
I just remembered that another member had posted a complete schematic of this soundcard's analog stages in the thread I mentioned earlier. Perhaps it would be helpful to follow ground paths. FWIW, I modified it taking inputs directly to the ADC buffer.
https://www.diyaudio.com/community/threads/behringer-umc-202hd-for-measurements.341309/post-6741244
https://www.diyaudio.com/community/threads/behringer-umc-202hd-for-measurements.341309/post-6741244
Hi hey...
Are you ref. to this EMU setup which was posted in this thread regarding the GND connection to the soundcard ?
Jesper.
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The test setup looks like this
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Thank's a lot for all your'e help guy's...
Really appreciate it
I'am modifying the Behringer right now, for the direct-IN mod, which MagicBus did on the other thread.
Will post my findings there i guess. MagicBus's thread
Jesper.
Hi folks, having bought all the gear last year I still have no idea but do have a new laptop so am trying to get this setup working again but will need handholding through this. My audio interface is a Motu M2. I would like to first of all set it up to do a loopback? to measure its own distortion?
So in preferences what do I choose and what do i connect together on the Motu?
So in preferences what do I choose and what do i connect together on the Motu?
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I think he might be referring to this post: https://www.diyaudio.com/community/...ion-measurements-with-rew.338511/post-6353901
I used the differential inputs and outputs to get slightly better results from the EMU 0404 USB.
Ok, figured the loopback test out, results look good?
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Looking at the specs of the Motu I would expect even better performance. Keep in mind that the sweetspots of THD+N are found on higher levels than for THD. And these are separate for audio in and audio out. Line-In is the best input available for measurements. I would be quite interested in the final sweet spots of your Motu.
I do you mean better loopback performance? If so what settings would you use in rew?