1 (edited by alexander.kb 2021-12-22 15:18:06)

Topic: UCX II technical glitch

Hi all,

First post here, I just received my first RME interface - a UCX II, bought from a major retailer (discounted as it was display stock). SW 24. I have it sending and receiving ADAT from the Motu 828 Mk3 below. RME is master and sending clock via word clock.

Everything seems in great condition. I've given it a few test runs and everything was working like magic... until...

I noticed one random occurring issue, has happened a few times now: The metering screen will go a flickering black and white, audio and clock out will drop.
Strangely the buttons and encoder continue to work fine and all menus internal appear as normal.

It happens very intermittently and is fixed by turning off and on...

I hope someone can help me diagnose and solve the issue. What do I do?

Images of normal and glitching. Apologies for the poor quality:
https://ibb.co/6NL9rjw
https://ibb.co/fnwQNfF

2

Re: UCX II technical glitch

Unfortunately there is no way around returning the unit for service. Sorry.

Regards
Matthias Carstens
RME

Re: UCX II technical glitch

I received my UCX II last week, coming from an UCX. What a great audio interface! Nice improvement in usability.

I noticed well audible plop noises at power on/off and crack noise at a change of sample rate.
Much better than the UCX but still well audible.

Are these effects the normal behavior? Thanks.

4 (edited by ramses 2021-12-23 10:48:42)

Re: UCX II technical glitch

Hi bejoro,

AFAIK you have noise reduction on "power-on" only for
- headphones outputs on all recording interfaces
- on analog outputs only for the bigger interfaces like 802, UFX, UFX II, UFX+ (+)

(+) See also my Excel Line 85 ("Damping of the switch-on crackling")
See Excel in this blog article: https://www.tonstudio-forum.de/blog/ind … B-MADIfac/
Direct link to Excel File: https://www.tonstudio-forum.de/index.ph … -04b-xlsx/

Could maybe be solved by connecting an ADI-2 DAC/Pro through ADAT (DAC+Pro) or AES (Pro only)
and assigning that channel in TM FX (UCX II) to "Main Out".

As I think that you have both devices you could try that.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13

Re: UCX II technical glitch

Hi Ramses,

Thank you very much for the quick and detailed reply.

Matthias (MC) wrote that the UCX II has the same soft power on/off like ADI-2 DAC/PRO. That's why I asumed the UCX II would be silent at power on/off and maybe also during sample rate changes.

So, if I understand you correctly, the plop noises at power on/off and crack noise at sample rate changes are normal behavior?

I just want to be sure that my new UCX II is not defective.

Yes I have also two ADI-2 PRO FS R BE here but I use the UCX II for measurements and the ADI-2 PROs for my demo (and my enjoyment of course). Two completely different use cases. Thank you anyway for the suggestion, good to know I have options, you'll never know.

6 (edited by ramses 2021-12-23 11:15:03)

Re: UCX II technical glitch

Not sure about noise during sample rate changes.
Just playing a game at 44.1.
If I change the sample rate of the UFX+ (clock master) from 44.1 to 48kHz (WDM driver part),
then the sound simply turns silent, when I change it back to 44.1 the sound comes back without any noise in front of it.

Setup: UFX+ (App using WDM part of MADIface ASIO driver)  --- AES ----- ADI-2 Pro FS R BE (clock slave, through AES)
MADIface driver: 0.9736

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13

Re: UCX II technical glitch

Thank you, that was fast.

Maybe Matthias or another UCX II user can say something about it.

I noticed the noise at change of sample rate in CC mode listening to music, different tracks, different SRs. Maybe that's important.

I will have to test this over ASIO. I have used USB/ASIO only for measurements and in this case I have a fixed SR.

8 (edited by ramses 2021-12-23 11:35:59)

Re: UCX II technical glitch

Checked now by playing back music with MusicBee (uses ASIO driver).
No noise when switching to double or quad speed music content and back to single speed.
Finally I switched back clock rate in driver settings from double speed back to 44.1.
Short pause of around 1 sec then again sound from game through WDM driver.
When being in a different sample rate the sound from game (in 44.1) is simply turned off.

Sry, no time to check with UFX+ in CC mode or with ADI-2 Pro alone.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13

9 (edited by bejoro 2021-12-23 14:00:27)

Re: UCX II technical glitch

Thanks a lot for your efforts, but I assume UFX+ and UCX II are very different devices.

I flashed the latest UCX II firmware 39/24/19 - 12/2021. A little confusing after flashing, because the UCX II still reports 24/03-2021 in Hardware/Diagnostics but FUT reports the actual firmware and "up to date". I wished RME would change that.

I used USB/ASIO and JRiver MC on Windows and the same behavior as in CC mode, output 1/2 to active monitor.

Crack/plopp at change of SR.

So, still my question, are these plopp noises with power on/off/SR change the expected behavior or is my device defective?

10

Re: UCX II technical glitch

I will check with my UCX II, but please don't expect that before 27...

Regards
Matthias Carstens
RME

Re: UCX II technical glitch

Thank you Matthias, that would be great. Next week is quite sufficient. 

Neither I nor my customers have ever had a defective RME unit.
I just want to play it save.

Frohe Weihnachten und geruhsame Feiertage!

Re: UCX II technical glitch

Some details of the setup:

Main out (1/2): 4 dBu
Main volume: -18 dB

Direct connection 1/2 to power amp/active monitors: 75 dB at listening position.

Good audible plopp noises at power on/power off.
Good audible crackling noises at change of sample rate (in CC mode, Linux/ALSA, in USB mode Windows/ASIO).

Audible crackling noises at change of track in CC mode Linux/ALSA, not tested on Windows.

ADI-2 PRO FS R BE is dead silent in all situations.

13

Re: UCX II technical glitch

I think the pop sound is normal. It is audible but muffled and far from an issue. Seeing your setting you could have it more than 10 dB lower in volume by adjusting the power amp, and if that is not possible by adding attenuators in-between. The pop-sound has the same level/volume at +13 and +19 dBu, which would make it already 15 dB more quiet with external attenuators. You said it yourself, the UCX II seems better in this regard than the UCX, so I doubt there is something wrong.

But the 'crackling noise' I can not reproduce at all. Neither by power on/off nor by changing sample rates in Windows, either via Settings dialog nor JRiver.

I use the latest firmware (which includes CC 19) and driver 1.219, buffer size 256, but the older firmwares did also not show such issues. Makes me wonder if your USB subsystem is working correctly. I also wonder how a 'change of track' which is just start/stop playback, could produce such a sound.

Regards
Matthias Carstens
RME

Re: UCX II technical glitch

Thank you very much for the feedback.

The pop sound at power on/off is not disturbingly loud. I just wanted to make sure the unit is ok. There is no crackling sound at power on/off.

I had already installed the latest firmware (UCX II firmware 39/24/19 - 12/2021) and latest Windows driver 1.219. Btw, UCX II HW diagnostics still reports 24 - 2021/3 and not 2021/21 but FUT reports the actual firmware and "up to date".

Regarding the crackling sound, I tested on an RasPi4 with Linux/ALSA (mpd, upmpdcli) and on an older Notebook which I primarily use for room and speaker measurements, Windows 10 21H1, USB 2.0 only. I was playing a track with 44.1 kHz and changing to a track with 96 kHz produced a good audible crackling sound (also back or other sampling rates). Both with RasPi4 over network and Windows Notebook with JRiver MC24 from USB flashdrive (I will update to MC28 and test again).

I assume with USB subsystem you mean the USB interface and/or USB device drivers?

I will try to investigate this even more systematically and also compare to my ADI-2 PROs again.
It puzzles me that you have no crackling sound at all.

15

Re: UCX II technical glitch

Me not - that is how it should be (and always is also with our other interfaces). Do you still have the UCX? That would be the perfect comparison. An ADI is not as it has less channels and uses a different USB transmission method under Windows.

BTW, the info displayed is correct as it only relates to the DSP version. And that one is from that exact date, it did not change with the latest FUT.

Regards
Matthias Carstens
RME

Re: UCX II technical glitch

Strange, I subscribed to this thread but I do not get any e-mail notifications.

It was not my intention at all to question the quality of RME products.

I have already sold my UCX.

I will check the crackling issues again and report back.

What do you mean by "USB subsystem"?
Any hints regarding this investigation?

17 (edited by bejoro 2021-12-29 15:32:44)

Re: UCX II technical glitch

Tested with 1/2 and 3/4 as main out, XLR, two different power amps, 1/2 or 3/4 completely turned down.

Windows 10 21H1, Driver 1.219

Driver Settings: changing sample rate produced well audible crackling sound.

Also crackling sound over phones when changing sample rate (also with power amp disconnected).

Analog input meter shows the crackling sound on different channels, sometimes only one or two channels, sometimes all 8 channels.

Any ideas?

Edit:
Crackling sound over phones is louder in high power mode.

Edit:
USB disconnected, only phones or only power amp.
Changing the sample rate in device menu "Options - Clock" produced the same crackling sound.

18

Re: UCX II technical glitch

bejoro wrote:

Driver Settings: changing sample rate produced well audible crackling sound.

This kind of description is not helpful, just confusing. Changing the sample rate is not possible in the Settings dialog with a running playback. ASIO will grey out the menu, WDM will be screwed. Correct test is to have an analog input signal routed via TM FX to an analog output and listening to it. Sample rate changes should be performed in real-time by the hardware with a very short mute (0.5 s), and no crackling. Watch theTM FX level meters if the crackling is shown somewhere.

In JRiver I have a playlist with songs of different sample rates, for example 44.1 and 48 kHz, but also 192 kHz. Playing all the tracks (via ASIO) the sample rate changes in realtime as needed and with zero crackling.

If you can do none of the above then maybe the UCX II is broken.

Edit: your last comment sounds like the TM FX routing test failed...

Regards
Matthias Carstens
RME

19 (edited by bejoro 2021-12-29 18:47:14)

Re: UCX II technical glitch

Now I am completely lost. I did not change the TM FX routing, everything default.
I changed main output to 4 dBu, main and phones volume, phones high/low and mic gain.

When I change the sample rate in Settings without playback it is crackling.
When I change the sample rate in device menu (USB disconnected) it is crackling.
When I change songs in JRiver (ASIO) with different sample rates it is crackling.
When I change songs in CC mode (Linux) with different sample rates it is crackling.

Obviously I am too stupid. A step by step guide would be helpful. Maybe there is a misconfiguratiin but I can't see it. It would be a disaster if the UCX II was broken.

20

Re: UCX II technical glitch

Not sure why you think you're stupid - those were good tests. And the only explanation I have now is that the unit is indeed defective. Warranty...

Regards
Matthias Carstens
RME

Re: UCX II technical glitch

Thank you Matthias, unfortunately that's a disaster.

I will try one last test, load the factory settings and try again.
Is there another device reset I could perform?

22

Re: UCX II technical glitch

No, that plus current firmware is all one can do.

Regards
Matthias Carstens
RME

Re: UCX II technical glitch

Is it a click when changing sample rates?  I have that.  The click is louder at +19 than +13.  I also have adi2 pro fs r and babyface pro fs.  The babyface has a click that is not as loud.  There is not a click on the adi 2 pro.   The click is also on my mackbook pro with the UCX II.  The click is on headphone and speaker outs.

24 (edited by bejoro 2021-12-31 14:43:07)

Re: UCX II technical glitch

MC wrote:

No, that plus current firmware is all one can do.

I have loaded the "Factory" setup. I just used the device menu "Options - Clock" to change the sample rate and unfortunately the crackling noise still happens.

The volume of this crackling noise is independent of the volume setting of main/phones.

The volume of this crackling noise seems identical at 4 dBu and 13 dBu and is significantly louder at 19 dBu. With phones the volume of this crackling noise is lower with the "low" setting and higher with the "high" setting.

With my setup it is not only a clicking sound, it is a disturbing crackling noise. I have the UCX II directly connected to my power amps. This crackling noise might be less disturbing if you have further attenuation devices (pre amp, mixing devices) in front of your power amp or monitor speakers.

Matthias, please excuse the question, but are you clearly of the opinion that there is a hardware defect and it is not a firmware glitch?

Re: UCX II technical glitch

I took a closer look at the problem with the interference signal when switching off and on and switching from the sample rate from 48 to 64 kHz on my RME UCX 2 and recorded it on a second audio interface of a competitor using a WAV file.

In both cases the loudness of the interfering signal is approx. -33 dBFS according to the RME DIGICheck.

Since this interfering signal is very quiet, I can live with this problem very well and see not a defect on this audio interface.

It would be more problematic if the interference signal were as loud or louder than the usual useful signal.

Re: UCX II technical glitch

It seems your UCX II is not defective.

The crackle of my UCX II is almost as loud as the useful signal, especially with 19 dBu or with "high" setting of the phones output.

27

Re: UCX II technical glitch

Andreas1 wrote:

I took a closer look at the problem with the interference signal when switching off and on and switching from the sample rate from 48 to 64 kHz on my RME UCX 2 and recorded it on a second audio interface of a competitor using a WAV file.

In both cases the loudness of the interfering signal is approx. -33 dBFS according to the RME DIGICheck.

Since this interfering signal is very quiet, I can live with this problem very well and see not a defect on this audio interface.

It would be more problematic if the interference signal were as loud or louder than the usual useful signal.

It would be helpful to check this recording. Can you upload it somewhere?

Also from the description I don't believe Bejoro talks about the same issue/signal. But having the recording would clear that.

Regards
Matthias Carstens
RME

28 (edited by bejoro 2022-01-01 12:58:37)

Re: UCX II technical glitch

Inspired by Andreas1 I tried another test.
Connected UCX II 1/2 OUT to Analog IN of ADI-2 PRO.

I hope I have configured this correctly. Please let me know if I my setup is flawed.
I have used DIGICheck 5.941 (Win10), it is easier to read the level meters than on the ADI-2 PRO.
Is DIGICheck fast enough to measure such short events correctly?

UCX II, Main Out 1/2: +19 dBu, Volume: 0.0 dB
ADI-2 PRO Analog IN, +19 dBu, 96 kHz (AD/DA mode), AD Filter: SD Sharp

No playback via UCX II (USB disconnected, USB mode).

Changing sample rate in device menu "Options - Clock":
Peak L: -43 dBfs
Peak R: -50 dBfs

Power ON:
Peak L: -48 dBfs
Peak R: -48 dBfs

Power OFF:
Peak L: -41 dBfs
Peak R: -43 dBfs

As said, with my power amp directly connected to the UCX II the crackle at sample rate change is very disturbingly loud, not extreme but at 4 dBu still almost as loud as the useful signal. The same for phones out (used headphones for testing: Sennheiser HD650)

I am trying to avoid having to send my UCX II back for repair or exchange because I need it very badly. But if it is defective, I will have to respond very soon, and this prolonged downtime would be a disaster.

Re: UCX II technical glitch

The values from my device are similar.

bejoro wrote:

As said, with my power amp directly connected to the UCX II the crackle at sample rate change is very disturbingly loud, not extreme but at 4 dBu still almost as loud as the useful signal.

I could also well imagine that one of the cables is defective or that you are not testing the test device in isolation from the other devices. Because with me such a crackle noise is not to be heard and also not perceptible in terms of measurement technology.

Re: UCX II technical glitch

MC wrote:

It would be helpful to check this recording. Can you upload it somewhere?

Unfortunately not. If I could have uploaded audio files to this server, I would have done it.

31 (edited by bejoro 2022-01-02 11:15:15)

Re: UCX II technical glitch

Andreas1 wrote:

The values from my device are similar.

bejoro wrote:

As said, with my power amp directly connected to the UCX II the crackle at sample rate change is very disturbingly loud, not extreme but at 4 dBu still almost as loud as the useful signal.

I could also well imagine that one of the cables is defective or that you are not testing the test device in isolation from the other devices. Because with me such a crackle noise is not to be heard and also not perceptible in terms of measurement technology.

Thanks, as mentioned, crackle also with headphones.

Edit:
Thank you again, Sorry I forgot to mention that I tested it with headphones only, the UCX II was completely isolated, nothing else connected besides headphones (and power supply of course  smile )

Re: UCX II technical glitch

@MC
Any comments about my measurements? Is the setup correct?
I could make a recording using Global Record of DIGIcheck and provide it for download.

33

Re: UCX II technical glitch

Please do.

Regards
Matthias Carstens
RME

34 (edited by bejoro 2022-01-04 10:15:51)

Re: UCX II technical glitch

Sorry for the delay. I am extremely busy this week.
I will make and send the recordings as soon as possible.
You will get an e-mail with download links soon.

Re: UCX II technical glitch

You've got mail. smile

36

Re: UCX II technical glitch

Your recordings match exactly what I get with my unit, so yours is not broken. I have several comments:

- First of all this is a click (sample rate change) and pop (power off) sound, a single event. Crackling means several clicks/ pops over a longer time. So there never was a 'crackling noise'.

- The values noted above are peak values. The loudness of these is better represented by RMS values, which are much lower, especially with power on/off.

- The click on sample rate change happens only when changing from single to double or quad speed. 44 to 48 or 176 to 192 is completely click-free. The reason is a reset of the clocks and ADC/DAC which is unavoidable.

- I noticed a loud click when changing from 128 to 176 kHz. That seems not ok, but is not an important issue. No one has music in 64 or 128 kHz sample rate, so this setting is never used for music playback.

Which brings me back to my post 13. You clearly have a big level mismatch between UCX II and power amp, and you need to make sure your music is played at normal levels, up to 0 dBFS. If I turn up the volume at my power amps so that the mentioned noises become audible, playing music will make my ears bleed. And that is also clearly shown by the numbers that you posted. How can a click at -50 dBFS be as loud as the played music? There is something fundamentally wrong here.

I would strongly advise to try attenuators at the UCX II output if you can't reduce the sensitivity of the power amp.

Regards
Matthias Carstens
RME

37 (edited by bejoro 2022-01-05 11:48:01)

Re: UCX II technical glitch

My UCX II has the same loud crackle also over headphones, as mentioned.
I have described the level situation in my previous posts.
My power amp is already attenuated.
Maybe the measurements are wrong, flawed setup.

I used the device menu to reproduce the effect for testing.

The loud crackle on main out and headphones happens also in usual listening situations like sample rate change caused by a track change from 44.1 to 96 etc.

38

Re: UCX II technical glitch

Sorry, forgot the headphone:

The click of sr change over headphone changes with the output ref level (6 dB louder at High Power), because then the amp gets a 6 dB higher level from the DAC, which is the one producing the click. It is more audible with higher sensitive headphones, as the volume control is digital, so no way to attenuate this (except for using the Low Power option).

The pop on power on/off is independent from the ref level because it is coming directly from the output stage. There is no mute relais for the phones output, so a certain pop noise is expected, but low in volume, so not dangerous. This is the same as on all our other interfaces. The volume of that pop depends on the used headphone. Low sensitivity ones show less pop (barely audible).

Please note the UCX II is not a HiFi oriented unit (as the ADIs) for totally click/pop free home use, but a production tool for the studio/music making. As such cost and space consuming features like headphone output relais are not part of this (all these) products.

Regards
Matthias Carstens
RME

39

Re: UCX II technical glitch

One more thing: I just compared the old UCX against the new one. Power-on pop is a bit lower, both ok. Power-off is much lower (better) with the UCX II. SR change is pretty similar.

That said we will have a look again. We were able to reduce the sr change click via firmware in several cases, maybe it can be optimized here as well.

Regards
Matthias Carstens
RME

Re: UCX II technical glitch

A question: At SR 44.1 or 48 The analog input meters linger between -102 and -104 when setting SR 192 they are between - 77 and -79 nothing connected?

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

Re: UCX II technical glitch

Happy_amateur wrote:

A question: At SR 44.1 or 48 The analog input meters linger between -102 and -104 when setting SR 192 they are between - 77 and -79 nothing connected?

Im Handbuch unter der URL https://www.rme-audio.de/downloads/fface_ucx2_d.pdf auf Seite 115 ist dieses Thema unter der Überschrift "40.6 Rauschabstand im DS-/QS-Betrieb" sehr gut beschrieben.

Re: UCX II technical glitch

Takk Andreas! Jeg hadde det et sted i bakhodet. Får visst ikke lest den manualen mange nok ganger smile

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

Re: UCX II technical glitch

MC wrote:

One more thing: I just compared the old UCX against the new one. Power-on pop is a bit lower, both ok. Power-off is much lower (better) with the UCX II. SR change is pretty similar.

That said we will have a look again. We were able to reduce the sr change click via firmware in several cases, maybe it can be optimized here as well.

Thanks, that would be great.

Today the power supply of my UCX II failed. No LED, different euro cable tested - dead.
Very disappointing.

Re: UCX II technical glitch

MC wrote:

The pop on power on/off is independent from the ref level because it is coming directly from the output stage. There is no mute relays for the phones output, so a certain pop noise is expected, but low in volume, so not dangerous.

Do the UCX II analog outputs have power-on pop suppression? How does it compare with the UFX II/+?

Fireface UCX II, BabyFace Pro, Fireface UFX, Fireface 400

Re: UCX II technical glitch

See my Excel in this blog, line 88
https://www.tonstudio-forum.de/blog/Ent … B-MADIfac/
Direct link to Excel file: https://www.tonstudio-forum.de/attachme … 4-08-xlsx/

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13

46 (edited by Manuel 2022-06-02 09:48:49)

Re: UCX II technical glitch

ramses wrote:

See my Excel in this blog, line 88
https://www.tonstudio-forum.de/blog/Ent … B-MADIfac/
Direct link to Excel file: https://www.tonstudio-forum.de/attachme … 4-08-xlsx/

Got it, many thanks, that answers my first question. Do you know if the UFX II and the UCX II use the same pop suppression technology? In other words, are there any differences in the quality of the power-on pop suppression between these two models?

Off-topic but why not put your list on Google Sheets? It's so much easier to work with than Excel, especially for searching text, and users could bookmark your document which means any changes you make are immediately available to everybody who has the link. This eliminates the need for users to scour the forum for a link to the (hopefully) latest version of the Excel file. Besides, Google Sheets has built-in version control, which should make your life easier.

Fireface UCX II, BabyFace Pro, Fireface UFX, Fireface 400

47 (edited by ramses 2022-06-02 09:48:55)

Re: UCX II technical glitch

I like the content / my intellectual property to be placed there, where I have access to it and a solid backup.
From there I upload this content to a platform which I trust -> the forum.
I personally do not like cloud platforms and use them only for very few cases where it also makes sense to me.

You can download the Excel free of charge, can modify a local copy to your demand, what do you want more ...

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13

48 (edited by Manuel 2022-06-02 10:00:41)

Re: UCX II technical glitch

ramses wrote:

I like the content / my intellectual property to be placed there, where I have access to it and a solid backup.
From there I upload this content to a platform which I trust -> the forum.
I personally do not like cloud platforms and use them only for very few cases where it also makes sense to me.

You can download the Excel free of charge, can modify a local copy to your demand, what do you want more ...

Fair enough, although you could still work in Sheets and download the file as .XLSX once every month just to have a safe local copy. I mean, it's not sensitive data since you are sharing it publicly, and you can't prevent anyone from uploading your file to Google Sheets and sharing it that way (hopefully crediting you for the work). I think most people would prefer the Google Sheets version for the convenience—just my 2c. Regardless, nice work.

(anyway, forget that, let's stay on-topic)

Fireface UCX II, BabyFace Pro, Fireface UFX, Fireface 400

49 (edited by sbcrikey 2022-06-02 15:20:25)

Re: UCX II technical glitch

ramses wrote:

See my Excel in this blog, line 88
https://www.tonstudio-forum.de/blog/Ent … B-MADIfac/
Direct link to Excel file: https://www.tonstudio-forum.de/attachme … 4-08-xlsx/

great spreadsheet Ramses! might I suggest a minor change to line 88 by saying "crackling/pop" when describing the power-on noise? I only bring that up since there was some discussion about describing the sound.

I was also going to ask @bejoro if he had any FX enabled when performing his tests. My thinking is that with enough reverb or echo, a pop could possibly sound like a crackle???

-Steve

Re: UCX II technical glitch

I had no FX enabled when I was performing my tests (default settings).