• Registered: 2020-08-14
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Topic: Would it ok to turn off Hardware preamp or compressor while connected?

I noticed on DigiCheck NG, that even the UFX analog in 1 is muted,
I see sudden pop on the analyzer when I turn my hardware preamp and compressor off.
Also *phantom power.


But I cannot turn everything off then turn on again just for the sake of safety...after recording...
um...
Is it totally fine or am I damaging my UFX mk1's analog ins...?!


Not huge but I definitely see popping movements whenever I turn hardware gears off.


Thanks.


*More info: I've been turning off this way for almost 7 years... (of course monitor speakers are muted smile)

2 Reply by MC

  • MC
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Re: Would it ok to turn off Hardware preamp or compressor while connected?

You should not unplug mic inputs while phantom power is switched on. All the rest is not a problem.

Regards
Matthias Carstens
RME

MC's Website

  • Registered: 2020-08-14
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Re: Would it ok to turn off Hardware preamp or compressor while connected?

MC wrote:

You should not unplug mic inputs while phantom power is switched on. All the rest is not a problem.

Thank you! But I am a bit confused here smile
So,

since, I connect my JZ v12 condenser mic -> Neve 1073 (phantom power on) -> 33609 compressor -> Avalon 747 EQ -> UFX 'LINE' in 1,

I 'can' turn the power off all my hardware gear even the line is connected...?


or, do you mean, is it better to turn UFX off whenever I want to turn my gears off...?

It is not connected to MIC in of UFX mk1 but LINE in since I use external hardware pre and compressor.



Cheers.

  • Registered: 2020-10-05
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Re: Would it ok to turn off Hardware preamp or compressor while connected?

It means do not plug or unplug cables with phantom power on it

ADI2, Digiface, ARC
  • Registered: 2020-08-14
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Re: Would it ok to turn off Hardware preamp or compressor while connected?

fieldstu wrote:

It means do not plug or unplug cables with phantom power on it


Sorry I am not fully understood smile

So, physically plugging and unplugging while phantom power on is not something that I do,

But, I 'can' leave my TRS cables connected to the Analog inputs (line level) of UFX and
powering on and off of my hardware preamp and compressor would not harm UFX's analog line level input of 1

Correct...?

6 Reply by ramses (edited by ramses 2022-08-20 12:03:37)

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Re: Would it ok to turn off Hardware preamp or compressor while connected?

The difference with Phantom power is, there you transfer 48V power to the connected condenser mic.

With normal connections (unbalanced/balanced) you should not have an issue, if you power off/on the connected device.

But also here I would be careful and at least turn your monitoring down …
If the input is in your monitoring, the audio impulse might be quite high and the resulting “plop” in the monitors / phones loud.

I would test this with the highest reference level offering most headroom.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14
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Re: Would it ok to turn off Hardware preamp or compressor while connected?

ramses wrote:

The difference with Phantom power is, there you transfer 48V power to the connected condenser mic.

With normal connections (unbalanced/balanced) you should not have an issue, if you power off/on the connected device.

But also here I would be careful and at least turn your monitoring down …
If the input is in your monitoring, the audio impulse might be quite high and the resulting “plop” in the monitors / phones loud.

I would test this with the highest reference level offering most headroom.

ok smile thanks! I was just worried, because DigiCheck NG showed a huge pop.. but of course I did muted LINE in 1 and also I always make sure that my monitors are muted too whenever I power on/off hardwares. thanks.

Well understood. (*This pop I am referring was due to Neve 1073 phantom power switch)

  • Registered: 2020-08-14
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Re: Would it ok to turn off Hardware preamp or compressor while connected?

ramses wrote:

The difference with Phantom power is, there you transfer 48V power to the connected condenser mic.

With normal connections (unbalanced/balanced) you should not have an issue, if you power off/on the connected device.

But also here I would be careful and at least turn your monitoring down …
If the input is in your monitoring, the audio impulse might be quite high and the resulting “plop” in the monitors / phones loud.

I would test this with the highest reference level offering most headroom.

*Oh just to clariy, my concern was only whether I might damage Analog line input of UFX mk1 back of the unit smile whenever I switch on and off phantom power of Neve 1073 preamp smile

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Re: Would it ok to turn off Hardware preamp or compressor while connected?

There is no difference, it's all the same on recording interface or external preamp.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14
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Re: Would it ok to turn off Hardware preamp or compressor while connected?

ramses wrote:

There is no difference, it's all the same on recording interface or external preamp.

I am extremely sorry to repeat myself,
but I am aware that I have to be careful about phantom power being on when I turn my hardware gears on and off when feeding into Analog input of UFX,

'but'

Would you please explain and elaborate,
why, even though the levels are fairly low, whenever I power on,
- synthesizer (Korg Triton, volume fairly medium)
- hardware stereo compressors (gain at 0, Neve 33609 stereo compressors/ input and output at 0, Avalon 747 compressors)

I see a little, and sometimes big 'pop' on DigiCheckNG, which means there are sudden 'pop'..

So these pops I am very worried about...
Because I want to keep my analog inputs as safe as possible...?


Are these 'powering-on/off-hardware' commonly make these little/big pops...? and I should be totally ok with it?!


Thanks!

Does it have to do with sudden powering 'current'/'voltage'...? Should I worry about it?
I am so sorry.. I just could not find the answer on the net...

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Re: Would it ok to turn off Hardware preamp or compressor while connected?

How high is the voltage of this “plop”?
If it is below +19 dBu = 6,9V, then you do not need to worry at all as the analog inputs support up to 19 dBu according to manual.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14
  • Registered: 2020-08-14
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Re: Would it ok to turn off Hardware preamp or compressor while connected?

ramses wrote:

How high is the voltage of this “plop”?
If it is below +19 dBu = 6,9V, then you do not need to worry at all as the analog inputs support up to 19 dBu according to manual.

Sorry for my ignorance,
But whenever I power on Avalon 747 stereo compressor: pops around -30dBFS on digicheck NG
33609 compressor pops around -20dBFS

and Korg Triton powering on around -5~ -3dBFS <-- (pretty big pop I can tell)


So, I was just worried smile

13 Reply by ramses (edited by ramses 2022-08-21 19:06:46)

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Re: Would it ok to turn off Hardware preamp or compressor while connected?

You are mixing analog and digital signal levels. It's not possible to convert dBFS ("zeros and ones") to dBu (Volt).
And we need to talk about input levels in dBu/Volt if you want to know whether you overload/damage your inputs.

Next, do you mean -3 dBFS RMS or peak value? If these should be RMS values, then the peaks are louder.

I would propose to measure the input voltage with a Volt meter, but I am uncertain whether those meters would be too sluggish for that purpose to catch the peaks.

Well, sorry, maybe somebody has a better / easier answer for you than me.

What I tried to achieve is to collect information so that we know about what input levels we talk concretely.
If it should turn out, that his is below the max. input level of the analog input, then you wouldn't need to be worried,
you would only have to turn the volume of your main monitors or headphones down.
Or to use attenuators to fix level mismatches. https://forum.rme-audio.de/viewtopic.php?id=25399

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