• Registered: 2015-04-05
  • Posts: 28

Topic: UFX III with external preamps

I just replaced my FF 802 with the UFX III and so far I'm loving it. The DURec is a game-changer for me, and I have much better CPU performance in Logic Pro.

I'm using the XLR inputs (9-12) for two external preamps. I'm using all the line inputs at the rear for hardware synths.

Would it be better to use the line inputs for the external pres or will it make much of a difference at all?

Thanks,

N






Logic Pro: 10.8.1 | Pro Tools: 2023.12 | OS X: 13.6.1 | Mac Studio M1 Ultra | Interface: UFX III

2 Reply by Ninbura (edited by Ninbura 2023-12-31 23:16:08)

  • From: Utah, USA
  • Registered: 2020-10-08
  • Posts: 104

Re: UFX III with external preamps

Your pre-amps are outputting line level, and the XLR inputs on the UFX III can accept line level. The 6.35mm TRS inputs on the back are all line level.

So, it's line level across the board, should be little to no difference. Mic/inst level must be interfaced using the front XLR/6.35mm combo jacks, but all analog input connections on the UFX III can be run at line level. There are slight differences in terms of channel controls. For example, the XLR combo jacks provide much more analog gain. If the input is particularly cold, this could be helpful.

Vast differences in cable quality could also present a difference.

2x MADI FX | Digiface Dante | Fireface UFX+ | ADI-192 DD
  • Registered: 2015-04-05
  • Posts: 28

Re: UFX III with external preamps

Thanks for the reply. Good to be reassured that the difference in quality would be nominal.

Cheers,

N

  • hb82
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  • Registered: 2021-10-07
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Re: UFX III with external preamps

There's negligible LF roll-off on the XLR inputs on the UFX, maybe newer models are the same (quick n dirty measurement below if img shows up) and the input impedance is ~2 kOhm rather than the more 'standard' ~10 kOhm per inputs 1-8.

I stumbled on this switching from a UFX to UCX (in contrast the mic/line inputs 1-2 on the UCX have the same electrical characteristics as the other line inputs (via TRS) and similarly inputs 3-4 are line level or instr via TRS or TS as switched on TotalMix).

Personally I think 9-12 on the UFX series should be labelled mic/instr. Amongst other things, it would avoid expectation of the electrical/gain characteristics being the same as 1-8 (e.g. as pointed out here: https://forum.rme-audio.de/viewtopic.php?id=36385) but just my opinion.

https://ibb.co/FYnY021

5 Reply by MC

  • MC
  • MC
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  • From: Germany/Thailand
  • Registered: 2007-04-06
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Re: UFX III with external preamps

hb82 wrote:

There's negligible LF roll-off on the XLR inputs on the UFX, maybe newer models are the same (quick n dirty measurement...

I recommend a quick 'n dirty view into the UFX III manual, section Tech Specs. Much quicker than doing measurements on a different and outdated unit.

Regards
Matthias Carstens
RME

MC's Website

6 Reply by hb82 (edited by hb82 2024-01-04 20:44:56)

  • hb82
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  • Registered: 2021-10-07
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Re: UFX III with external preamps

Makes sense and it's nice RME provide this level of spec - I just had this to hand as I was testing my interfaces and prefer graphs.

But since I added this info based on my UFX, for avoidance of doubt....Any roll-off on 9-12 likely occurs 5 Hz down on the II and III (not that it really mattered much on the UFX) and the input impedance of the II and III is 3.4 kOhm.