1 (edited by aroom 2019-01-28 10:56:40)

Topic: Does clipping harm pre-amp?

Hi,

I'm using the two mic inputs of my Fireface UC to capture ambient sound on stage in a theatre set. I'm using two static mics to treat the signal with Ableton Live. I have to push up to 44 dB to get significant signal, because it's a rather quiet scene. But most of the time, the sound will be louder on stage, so I just muted the input in Ableton Live, but the two mics in are clipping.

My question is : will it damage the preamps if they are clipping during a rather long period of time?


Thanks for your help.

Re: Does clipping harm pre-amp?

No direct answer to your question but I have a proposal.

Maybe the UFX II would support you in two ways

1. the gain range of the Mic Inputs is higher (75dB). This is one of the many improvements that RME introduces with the latest flagship interfaces UFX+/UFXII over the older model UFX (which was already superior to UC). By this you will most likely get less noise and you will have more headroom.

2. the UFX II supports AutoSet which is an automatic overload protection, see handbook chapter 19.2.
https://archiv.rme-audio.de/download/ff … plus_d.pdf

In your scenario you would perform the following tasks:

1. set the gain settings of the two Mic inputs of the UFX II to the same level (in stereo mode the gain settings affect both channels, individual settings for L and R channel are not possible.
2. activate AutoSet on the Mic stereo channel, by this the automatic gain adjustment works for both channels
3. Choose a proper Gain
4. If the music becomes louder than -6dBFS AutoSet will automatically reduce the Gain to reach -6dBFS again.
5. In quiet scenese you need to manually increase the gain slowly

The advantage for you is now, that during the run of the whole concert you only need to adjust the gain up in quiet scenes (step #5), the rest is being handled automatically by AutoSet...

Additional advantages of the UFX II for you:
- you can operate the UFX II completely stanalone with the display, this has been enhanced further by RME
- you can plug an USB Stick or USB disk (SSD/HD) to the USB port in the front and
--- either record completely stand-alone without any need for a PC
--- record in parallel to the PC recording to have a backup recording shall the PC have an issue during recording
- you can plug the ARC USB to the USB port in the back of the unit to have more comfort in standalone operation
- you can prepare an USB stick for pause music and play it back via the UFX II if you have active monitors connected
- you have a 2nd phones output for a 2nd person to operate the unit
- you can use a cheap netbook to operate the unit with TotalMix FX if there is a certain demand for it in standalone mode
- you can use ethernet or WiFi connection between two Laptops to make use of TotalMix Remote.
Then you can operate the UFX II with TM FX from workplace #1 and using TM FX Remote from workplace #2
- you can use the device in Class Compliant mode to record with an iPAD (and DURec in parallel as backup recording)
- you can use use the TM FX iPad application to control the UFX II with an iPAD.

Lots of options and ... you have still 2 further Mic inputs free ...

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14

3 (edited by aroom 2019-01-28 10:57:45)

Re: Does clipping harm pre-amp?

Thanks for your inputs,  the UFX+/UFXII interfaces looks really great. Unfortunately, I don't have the budget for such an upgrade and while touring, the smallest form factor from the UC or UCX is a better option for me. But thanks for taking the time.

If someone confirm that clipping is harmful for the hardware, I will simply control the gain with OSC from QLab during the show. If it's not harmful, it will only shorten the life of those two little red LED.

Re: Does clipping harm pre-amp?

UCX also has AutoSet.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14

Re: Does clipping harm pre-amp?

After some deeper research on the forum, I found this statement regarding the ADI-2 Pro:

The protection is designed to work up until 21 Vrms or 60 Vpp or 28.7 dBu unbalanced and 34.7 dBu balanced. Above that expect some smoke signs coming out of the unit...

https://www.forum.rme-audio.de/viewtopi … 10#p134010

I've no idea about how to relate on those measures in real life.

So I don't know about the UC, but it seems like clipping is fine till it's not anymore. But at least I'll be noticed by smokes signals.

Re: Does clipping harm pre-amp?

You're only clipping the converter here, not the analog input. So no significant risk, I would think...

Regards
Daniel Fuchs
RME

Regards
Daniel Fuchs
RME

Re: Does clipping harm pre-amp?

Thanks Daniel for your answer.