Much difference in dBFS using a TR cable instead TRS cable

[matteocandura]

Hello there,
I tried my Moog Minitaur with a cable 1mt TRS (balanced stereo) Jack 6.3mm (Vovox Sonorus) directly connected to my UCX RME, and I noticed that reproducing the same sound with a cable 1mt TR (mono unbalance) Jack 6.3mm (Klotz), the dBFS doubled (in logic pro X mixer) Why?

Thanks,
Best.

Matteo Candura

[MC]

The Minitaur doesn't have a balanced output.

If you connected a TRS cable to it, then the ring is open ended. If the UCX RME has balanced inputs, the result of connecting that TRS cable would result in one of the differential inputs to be unreferenced due to the open ended ring. Depending on how the balanced input circuit is comprised, an unreferenced input can result in loss of signal and that can cause a signal drop.

Using a TS mono unbalanced cable plugged into the TRS of your UCX RME, now the ring of the balanced input is referenced to ground. What you did was basically completed a circuit in the balanced input of the UCX RME which was the way it was supposed to be working.

Nothing wrong with the Minitaur or your DAW - you just used the wrong cable.

[paramnesia]

see also
http://www.sweetwater.com/insync/what-i ... io-signal/