1 (edited by Vocalpoint 2021-12-30 18:24:20)

Topic: Using External Preamps with UCX II


I have ordered a new UCX II and my question today surrounds the operation of the Mic/Line inputs (1+2) on the UCX II vs Inputs 1 and 2 on my trusty Multiface II (That I have used for 10 years now)

I divide my time between professional voiceover for radio/TV/multimedia and of course my own music composition. For the VO work - I use a UA 610MKII mic preamp with my Rode NTV and it's sounds fantastic.

In my current setup - I take the line level out of the LA610MKII (XLR to TRS balanced cable) into Input One of the Multiface. As the Multiface inputs have no actual gain settings (Or preamps?) - I can nicely control all gain right on the UA and record my vocal into Studio One with perfect levels.

Now - my understanding of the UCX II is that the front Mic/Line combo jacks are actually preamps as well with their own input gain (1 + 2) which CAN be controlled via the big encoder knob - which make me think I will now have competing preamps and gain structures to wrestle with if I decide to use Mic/Line 1 for my UA 610MKII.

Another question: Are the mic preamps always inline in the UCX II - if one plugs a TRS cable into the combo jacks (Mic/Line 1 or 2) instead of using an actual XLR?

My requirement is to let the UA 610MKII handle all gain and coloration of the Rode NTV mic and just have the UCX II handle the AD/DA conversion. Maybe I need to use one of the Line inputs on the back of the UCX II - which looks exactly like the 8 Line inputs in my Multiface? (not sure if they have internal gain control or not)

Appreciate an information from anyone out there using any modern RME interface (that features internal gain controls) with their favorite outboard mic preamp.



EDIT: I think I may have my answer from RME support from this older post regarding the original UCX I


Would this still be valid for the new UCX II:

Inputs 5-8 don't bypass the pres, they just don't have any. 1-4 can also be used for line signal. While there is no physical bypass, at 0 dB gain, signals are not affected by the pres.

2 (edited by jaduffy007 2022-05-23 16:00:38)

Re: Using External Preamps with UCX II

I'm disappointed to see there's no reply to this post...as "bypassing" the pres in the UCX II is an important factor in my purchasing decision.

3 (edited by sbcrikey 2022-05-23 15:59:58)

Re: Using External Preamps with UCX II

page 40 of the UCXII manual states:

...the front XLR input can also be used as balanced and unbalanced Line input.

The TRS jacks of the two combo jacks are free of phantom power and fully compatible to unbalanced (mono jack) sources. They have a fixed level attenuation of 6 dB. The maximum input level is therefore +24 dBu, balanced and unbalanced.

doesn't sound like you should have a problem. any particular reason you wouldn't just run the external mic and preamp through line in 3/4?

Re: Using External Preamps with UCX II

Look to UCXII manual p.40 - 41 I/O and p.108 tech spec. Manual avaliable at product page -> downloads.

In tech spec line input  1-2, 3-4, and 5-8 have some difference in electrical specs. I dont know what this means for you, but there you have it.

Use TRS to access balanced line inputs at input 1-2. TRS is devoid of 48v.

ADI-2 DAC, ADI-2 PRO, DigifaceUSB, UCXII, ARC, HEGEL.h80, KEF.ls50, HD650, ie400pro _,.\''/.,_

Re: Using External Preamps with UCX II

Thanks guys

Re: Using External Preamps with UCX II

Nothing to "bypass", the preamps do not affect the signal if no gain is added.

Daniel Fuchs

Re: Using External Preamps with UCX II

Thanks Daniel.  I just pre-ordered a UCX II from Sweetwater.