• Registered: 2023-05-16
  • Posts: 11

Topic: UFX II Distorts in Standalone Mode

Hello, new user here, hope I'm posting in the correct place..

My UFX II instr inputs 9-12 are distorting when routed through the internal digital mixer.  Please help

The distortion gets worse when sample rate increases.  A small distortion is present at 44.1k.  At 192k it is a lot of distortion.

The distortion only happens when I play P-bass directly into the inputs.  The distortion occurs at a specific quiet note volume.  I can produce the distorted tone with any P-bass, I have tried 7 different instruments and ruled out the bass itself.  The issue occurs in all 4 preamps.  Have not noticed any distortion when using the mic inputs with a 48v mic.

The distorted sound is not present in recordings of the inputs, only direct monitoring.

The distortion occurs when the UFX is not connected to a PC (also occurs when it is).

I can cause the distortion by plucking at a soft volume.  Or by playing a sustained note and manipulating the volume control on the bass so i hit the distorting volume level.

Need help eliminating the distortion

2 Reply by MC

  • MC
  • MC
  • Administrator
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  • From: Germany/Thailand
  • Registered: 2007-04-06
  • Posts: 25,599

Re: UFX II Distorts in Standalone Mode

The first thing is to post your TotalMix FX routing with active level meters when that distortion happens, as screenshots from mixer and matrix view. If it is not in recording but only in monitoring then something seems wrong for that.

Regards
Matthias Carstens
RME

MC's Website

  • From: Germany
  • Registered: 2007-04-10
  • Posts: 9,776

Re: UFX II Distorts in Standalone Mode

Perhaps have a look at it when connected to the computer. Do you see any signals peaking in Totalmix? If so, where exactly? This is all a bit vague as it is, sorry.

Regards
Daniel Fuchs
RME

RME Support's Website

  • Registered: 2023-05-16
  • Posts: 11

Re: UFX II Distorts in Standalone Mode

Hey, the input channel 9 is routed directly to the analog output 1-2.  The level is far below clipping.

There is no EQ, dynamics, or FX applied.  The distortion does not happen when the level is higher.  It only happens at this medium-soft level.

I have taken a screenshot of totalmix settings, the distortion is audible with these settings and level.
Photo is here:
https://drive.google.com/file/d/17jirGx … share_link

Once again, switching to a lower sampling rate lessens the distortion.

Thanks for the responses.

  • Registered: 2023-05-16
  • Posts: 11

Re: UFX II Distorts in Standalone Mode

Hello MC, I have added a screenshot of the matrix in addition to the mix view.  Let me know if any ideas.

image here:
https://drive.google.com/file/d/1w4cN89 … share_link


thanks

  • Registered: 2023-05-16
  • Posts: 11

Re: UFX II Distorts in Standalone Mode

More info:

The distortion is audible in the headphones output and main output, regardless of level volume for the outputs.

  • Registered: 2023-03-26
  • Posts: 42

Re: UFX II Distorts in Standalone Mode

You set the input to instrument level? I can't remember exactly what it's called. I had the same thing before I switched it.

  • Registered: 2023-05-16
  • Posts: 11

Re: UFX II Distorts in Standalone Mode

Yes, you can see in the screenshot that the channel is set to inst.

  • Registered: 2023-05-16
  • Posts: 11

Re: UFX II Distorts in Standalone Mode

TLDR:

All 4 instrument preamps on my UFX ii sound crappy and distorted when playing bass direct in. 

The distortion is audible when monitoring through the UFX directly, independent of a computer.

The distortion is worse at high sampling rates

Any help would be appreciated

  • Registered: 2023-05-16
  • Posts: 11

Re: UFX II Distorts in Standalone Mode

Bump.. any ideas? 

Has anyone tried playing bass guitar directly into the instr. inputs?

11 Reply by korsynx (edited by korsynx 2023-05-18 08:22:42)

  • Registered: 2023-05-16
  • Posts: 11

Re: UFX II Distorts in Standalone Mode

I've now tested this quite a bit, and the cause of the distortion appears to be the sampling rate in the UFX ii.
Sampling rates of 96KHz and above all produce bad distortion when using the instr. inputs routed through the internal digital mixer (computer connected or not)

Edit, there is still a bit of distortion at 88.2 and 64KHz.  Even 44.1 and 48 are affected.  At 44.1 and 48 you might not notice the distortion, but if you listen to the distortion at the higher sampling rates, you can recognize it and hear it occurring occasionally at 44.1 and 48.

Edit:  After narrowing it down to the sampling rate, I used a synth played at the same volume as the bass was, and tested the non-instr inputs. 

Now can confirm that this problem is happening on all the analog inputs, they crackle and distort at any sampling rate over 44.1KHz.

At 44.1KHz are occasional clicks and pops and distortion.


Anyone have an idea for a solution to this problem?

  • Registered: 2016-06-14
  • Posts: 1,142

Re: UFX II Distorts in Standalone Mode

Hi
To me it looks like a faulty unit.
Anyway my questions as follows:
- do you have bought the UFX II new or 2nd hand?
- did it work properly once before?
- have you tried a Totalmix reset?
- what firmware is on it?
- what computer OS and driver version? (I’m aware the issue occurs in standalone mode)
- are there some other devices connected to the UFX II over ADAT, SPDIF, AES?

UCX - FF 400 - Babyface pro - Digiface USB - ADI-2 (original)
Mac mini M1 - Macbook pro - iPad Air2

13 Reply by korsynx (edited by korsynx 2023-05-18 16:01:48)

  • Registered: 2023-05-16
  • Posts: 11

Re: UFX II Distorts in Standalone Mode

Hello oli77sch, thanks for the help.

Just tried a totalmix reset, but the totalMix setting i was using was only 1 analog input routed directly to the main output, unity gain on both, low to mid level signal, no effects, no eq.. 
Resetting totalmix results in the same mix I had before when you raise the volume on the input channel.

Distortion still happening

According to your suggestion, I updated the firmware to newest version, now running
USB 111, DSP 14, CC 108 (HW-Rev.E)

Distortion still happening.

Computer is a ryzen 9 5950x, windows 10

There is nothing connected to the UFX except a synth into analog 1-2, a mic into mic input 12, and monitor speakers plugged into the main output.  Nothing digital connected.

  • Registered: 2023-05-16
  • Posts: 11

Re: UFX II Distorts in Standalone Mode

Update: I called RME support.  Their phone support tech was very good.  We did some tests and made the following note of the problem:

"Distortion on analog inputs, which is increasingly noticeable as sampling rate is increased.  Distortion happens when signal is in the mid-range of input level meter."

We checked serial number and the device is under warrantee.  They have offered to test the device and repair it if needed free of charge. 

I will try to update here on the forum with any further info.