I have a ProChannel Preset I created which has nothing in it but the (turned-off) EQ (since I don't think you can delete that).  I make sure that loads that by default on all channels in my starting template.  No noise problems.  I was getting weird noise intermittently recently, however, from a wifi range extender.

Long time Sonar (and previous Cakewalk xx) user here, but obviously first post :). I had the exact same issue, eventually also tracked down to the Pro-channel. I changed Audio interfaces, operating systems, multiple sonar revisions in between and no change. I contacted support and after 6 weeks of getting them to try and engage beyond 'please send me this output'...upload...no response for a week....send multiple emails asking for an update....get apologetic replies for delays etc. but NO answer or concrete suggestion for anything I hadn't already tried and listed in the emails, I just gave up. It is on the surface a very low level signal but I am more worried about harmonics and it's effect on audio further into the audible spectrum when added into the processing chain for the track, also when it happens across multiple tracks it starts to become more of an issue.
 
I love Sonar itself but the Pro-Channel is dead for me, as is Cakewalk support (this was my 2nd time using them in over a decade of purchasing their products, not very impressed).
 
Here are some visuals of what I captured in Insight and Nugen with no audio playing (no inputs either, I work purely with softsynths).
 

 

ahriakin@whisperbetweenworlds.com
Long time Sonar (and previous Cakewalk xx) user here, but obviously first post :). I had the exact same issue, eventually also tracked down to the Pro-channel.

Hi Derek. Welcome aboard so to speak. Can you clarify under what circumstances you're seeing the noise spectrum you posted?
 
The Prochannel by itself should not (and does not in my experience) generate any signal. So far this thread has established only that the PC76 U-type Compressor module generates quiescent noise with no input signal. But the spectrum I'm seeing is much different from the one you posted (I can post a screenshot later).
 
I just want to make sure you're really seeing the same issue, and not something else that needs to be investigated separately.
 
If it's just the PC76 that's causing concern, that's easily avoided and shouldn't scare anyone away from using the Prochannel in general.
 
 
 

That looks like emulated mains hum.

Quite a lot of plugins add fake mains hum because some of the "character" of the original hardware was the intermodulation it added between the audio signal and the electrical noise the circuit created. Waves often even give you the choice between mains hum at 50 or 60 Hz.

tlw
That looks like emulated mains hum.

Quite a lot of plugins add fake mains hum because some of the "character" of the original hardware was the intermodulation it added between the audio signal and the electrical noise the circuit created. Waves often even give you the choice between mains hum at 50 or 60 Hz.

When I reviewed the Waves Aphex Aural Exciter I asked why they included noise in it. They said that in critical listening tests, when they blind A/Bed versions with and without noise, several engineers said the version without noise "didn't sound right." However, they had the good sense to make the noise switchable. I prefer it without the noise 

I like puzzles, and I like testing things. So here's what I did, starting from a new project.
 

• Created a track with the ProChannel enabled, the PC-76 U-Type compressor set to the default position, and all outputs assigned to the master bus.
• Cloned this track 200 times (and found out Noel wasn't kidding about speed optimization...)
• Set the master bus meter to the 90 dB range.

 
I could not hear anything, nor did anything register in the meter. So I tried the same thing again, except with the PC-76 input up all the way, output up all the way, infinite compression ratio, no attack, full release. There was still no signal in the master bus.
 
Then I turned up the input gain on all channels to maximum and all channel faders to maximum. Still no signal in the master bus. Turned the master bus gain up full...still no signal.
 
You'd think that if the PC-76 generated some kind of signal, stacking 200 of them with everything turned up to full would reveal it, but there was nothing. The only thing of interest was that if you click on the meter screw while holding Ctrl+Alt, you can change its position. However, this still didn't make a difference (and I have no clue what this does...). No matter what I did, there was no signal on the master bus.
 
I'll try again later with headphones instead of speakers and a headphone amp I can turn up really loud. I'm not saying there isn't anything, but the conditions described didn't reveal anything.
 

Anderton
I like puzzles, and I like testing things. So here's what I did, starting from a new project.
 

• Created a track with the ProChannel enabled, the PC-76 U-Type compressor set to the default position, and all outputs assigned to the master bus.
• Cloned this track 200 times (and found out Noel wasn't kidding about speed optimization...)

 
(...)

Hi Craig, would you repeat the same experiment with PC4K ?  I had  c. 16 tracks and somehow PC4K switched itself on without my knowledge. I heard strange noise when all echos were off and transport stopped. Quick investigation pointed to PC4K.

If it's not showing in a spectrum analyser and the peak value on the track isn't showing any signal then I wouldn't expect cloning the track to have an effect. I was seeing a clear and measurable tone on just one channel although it needed about 60dB of gain to be audible. And it was definitely the ProChannel.

Kylotan
If it's not showing in a spectrum analyser and the peak value on the track isn't showing any signal then I wouldn't expect cloning the track to have an effect

 
Well, the key was your saying it was a very low-level signal that you could hear only if you added about 60 dB of gain. If something that's an inherent characteristic of the ProChannel or the PC-76 produces noise, then to eliminate the variable of whatever is adding the 60 dB of gain, it seemed logical to stack a couple hundred ProChannels in parallel. That would be equivalent to amplifying the signal by over 20 dB. Then there was the additional amplification of turning up all the faders, turning up all the input gains, turning up all the compressor outputs, etc. I would think if noise was being generated by the PC-76 or the ProChannel itself, any residual signal would become clearly audible under those circumstances but that's not what I experienced. As to it happening in only one channel, I assume that the code for all ProChannels and PC-76s is identical.
 
Obviously I'm not duplicating your exact setup because I don't know the details...for example, what's adding the 60 dB of gain, whether the transport is running or not, etc. But it seems the above would indicate that any noise is not from the ProChannel or the PC-76 by itself. However, I didn't get a chance to check with headphones although that introduces the variable of the headphone amp in the audio interface, and the audio interface itself will have a noise floor and the potential to pick up interference via the USB line. So to eliminate that variable, it would be best to try and stick solely to the SONAR environment, and try to create a situation where the noise registers at SONAR's output.
 

I did mention my setup above - no transport, no input assigned, no input monitoring, no plugins. Literally I can just open up any project, add a track, drag the Output dial in the ProChannel, and that signal's right there.
 
Sorry for the file size, but here's one of my lovely screencapture GIFs showing my reproduction case in a fresh project.

 
You can see the noise is very quiet, but when the FX bin then contains a guitar distortion pedal, an amp sim, a cab sim, there's enough gain to push that up into the audible range. (It's not the gain that causes the problem, just the thing that alerted me to its existence. That, and the bug which switched on ProChannels across a bunch of my tracks.)