Audition recording distortion, atypical wave patterns

[paulh2621331]

Hello - not sure what I am wrong here, I am using a warm audio wa-47 mic and a scarlet 2i2 3rd gen preamp - get some distortion especially when pausing/stopping. I attached a sample of my waveform, it does not look normal...recorded in mono 

[SteveG_AudioMasters_]

Can you provide a bit of the audio? From what I can see in the waveform at various points, it looks as though you may have a grounding issue with a mic cable...

[paulh2621331]

I warmed up the mic for over an hour, just to make sure that's not the issue.

Recorded again, with the WA-47 mic, same result and I am uploading audio and waveform.

I also recorded a test on my old CAD mic - seemed to be fine and I did not even bother warming the mic up. Attaching that audio as well as waveform.

You mentioned a possible grounding issue - my desk is glass with some metal parts, could that cause audio problems?

Thank you

[SteveG_AudioMasters_]

Okay, I've had a careful look at the waveform now. Let me draw your attention to one part of it (the end bit - the word 'three' amplified for clarity):

What you are seeing there isn't a grounding issue as such, but a pretty large shift in the DC level of the output, looking for all the world like a damped LF oscillation. This is not that unusual to a small degree with valve mics, but this is definitely too much - it's shifting about all over the place. So I looked up what others have reported about these Warm Audio mics, and it would appear that you're not alone in having difficulties, especially with the valve in them - they are a bit notorious, as are a few of the other components. What is a little bit strange though is that this is a transformer-output mic, and the transformer should isolate anything with a frequency that low from the valve itself - so basically this is far from clear, and as far as I can go without having the mic itself to look at.

The good news is that most of the comments seem to indicate that W.A. are generally pretty helpful about issues with these mics, so it's definitely worth contacting them to see what they say.

[paulh2621331]

Thank you - I will follow up with Warm Audio and let you know what happens. 

[paulh2621331]

Update - I notified Warm Audio and forwarded my audio to them - they asked me if I was close to the mic when recording because in their words "it is a very hot mic". I have similar issues when keeping distance and turning down the gain

[SteveG_AudioMasters_]

I think they'll have to try a little harder than that. They should stop making excuses and actually investigate what happens. I think that you've proved reasonably satisfactorily that it's their mic - assuming that you just plugged the CAD into the same preamp...

[paulh2621331]

They are sending me a replacement tube - I will let you know how that goes

[paulh2621331]

Warm Audio sent a replacement tube but nothing changed. I sending the mic to them so they can check it out. They said "Since this problem not being a tube issue is incredibly unusual, it's possible we may not be able to fix the issue. We can however promise that it will be extensively tested at no cost to you"

-I wonder if it could be the power supply or something non-microphone related. I'll update once they tell me the outcome. Thank you.