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Contributor - Level 1

Uphoria UM2 Questions

I recently adquired my very first audio interface, a Behringer Uphoria UM2. The UM2 has two inputs: a dual XLR / Line and other one called Inst. Reading the manual I found out that the dual input has low impedance (3K) and a max. input level of +2 dBu for the XLR and +22 dBu for the Line. On the other hand,the Inst input has high impedance (1M) and a max. input level of +2 dBu. Is it true that low impedance inputs works with pre amplifed signals, whereas high impedance inputs works with nonpre amplified signals?

The XLR input has the same max. input level as the Inst input but the XLR input is for low impedance whereas the Inst input is for high impedance. What does this stands for?

The interface produces hiss noise when the signal gain is augmented. I have already installed the Behringer and ASIO4ALL drivers. Is it because the interface works with USB 1.1 but the behringer driver is installed in a USB 2.0 port? Or is it beacause of UM2 XENYX preamp? Do I have to set my DAW mixer to 16 bit sync or force the drive to work to 16 bits?
ManuelArturoÁlv Contributor - Level 1 2019-01-28

2019-01-28

Uphoria UM2 Questions

I recently adquired my very first audio interface, a Behringer Uphoria UM2. The UM2 has two inputs: a dual XLR / Line and other one called Inst. Reading the manual I found out that the dual input has low impedance (3K) and a max. input level of +2 dBu for the XLR and +22 dBu for the Line. On the other hand,the Inst input has high impedance (1M) and a max. input level of +2 dBu. Is it true that low impedance inputs works with pre amplifed signals, whereas high impedance inputs works with nonpre amplified signals?

The XLR input has the same max. input level as the Inst input but the XLR input is for low impedance whereas the Inst input is for high impedance. What does this stands for?

The interface produces hiss noise when the signal gain is augmented. I have already installed the Behringer and ASIO4ALL drivers. Is it because the interface works with USB 1.1 but the behringer driver is installed in a USB 2.0 port? Or is it beacause of UM2 XENYX preamp? Do I have to set my DAW mixer to 16 bit sync or force the drive to work to 16 bits?

Valued Contributor - Level 1

Re: Uphoria UM2 Questions

Manuel Arturo Álvarez González;159530 wrote:
I recently adquired my very first audio interface, a Behringer Uphoria UM2. The UM2 has two inputs: a dual XLR / Line and other one called Inst. Reading the manual I found out that the dual input has low impedance (3K) and a max. input level of +2 dBu for the XLR and +22 dBu for the Line. On the other hand,the Inst input has high impedance (1M) and a max. input level of +2 dBu. Is it true that low impedance inputs works with pre amplifed signals, whereas high impedance inputs works with nonpre amplified signals?

The XLR input has the same max. input level as the Inst input but the XLR input is for low impedance whereas the Inst input is for high impedance. What does this stands for?

The interface produces hiss noise when the signal gain is augmented. I have already installed the Behringer and ASIO4ALL drivers. Is it because the interface works with USB 1.1 but the behringer driver is installed in a USB 2.0 port? Or is it beacause of UM2 XENYX preamp? Do I have to set my DAW mixer to 16 bit sync or force the drive to work to 16 bits?

HI Manuel,

Welcome to the forums. The "u" in dBu stands for "unloaded". They will not be the same voltage level in a lo-Z vs. Hi-Z input.

Impedance means the input has a certain amount of "load" across its input. In the case of high impedance the load is higher so therefore the the signal level will see less of a load for the same signal voltage.

Hi-Z inputs are typically used for instruments (thus labelled INST) that do not have powered driver circuits such as guitars. Microphones and other devices that have line level outputs are used in the lo-Z XLR/TRS combo inputs.

Hiss on an input when the gain is increased usually means that the gain is too high. Remember, turning up the gain on a pre-amp amplifies not only the signal but also any noise on the input. You want to set your input signal level to around -20dB. If you are hearing a hiss at that level you should locate the source of the noise on the input and correct that.

USB port speed and DAW bitrate won't cause nor fix noise on an input.

Hope this helps,
Ken
If you want "Loud", then run a piece of sheet metal through a table saw. --Ivan Beaver