I have a problem that recurs

Hey!! First, thanks for listening.
 
The first time I bumped into this issue was here...
http://forum.cakewalk.com/m/tm.aspx?m=3103460
 
I was recording at a house where 2 different mics seemed to make a clippish sound on the same channel fed into my Tascam. The wave form seemed normal below zero but limited above zero. I tested the Mics at home and they both worked great when using only those mics.
 
I went out two Sundays ago and recorded 18 tracks for the first time. I was using new equipment too. I was using the RME UCX with an Audient ASP880 and s tascam 2488. I was syncing the RME to the Tascam. 
 
The RME was clock sync'd using the SPIDF to the Tascam.
The Audient was locked to the RME using the Word Clock Cable.
 
Is this a clock sync issue maybe? The last time the problem occurred the RME was locked to tascam, but that was the end of the chain.

This time,
The Mics that had issues included
The MXL Guitar Cube direct to RME UCX PreAmp.
The KM184 to the RME Quad Mic Pre to the RME UCX
Gary's dynamic vocal to the Tascam 2488 (this even writes to a different hard drive!!).
 
Here is a sample...
http://stabilitynetwork.blob.core.windows.net/g-tunes/20150315_Susan_distortionsample.mp3

The Times the various Mics had issues didn't overlap.

In November, the issue only showed up on channel three of the tascam and it happened for two different MXL condenser Mics. This time, it also happened on a dynamic, not one I own. I suppose I should ask to make sure it wasn't a condenser since it would have had phantom power through the Tascam.

The problem tends to show up at louder moments, but it is random. It happened on a couple of quiet moments too.

Hi Geoff,
I've never used devices being sync'd with a clock, that's above my pay grade.  But this particular problem doesn't seem to me like it would be a clock problem.  clock problems are typically gong to cause timing issues, I don't think they can cause amplitude issues, but I could be mistaken.
 
I had a similar problem (again!) with this situation just recently and it was driving me nuts.  no matter what preamp I used, no matter which microphone I used, my recording in Sonar was limited at -7dB.  I adjusted my MOTU software and increased the gain on the inputs, I made sure my MOTU software's compressor was off.  I tried turning it on even, nothing seemed to stop it from doing this.  and the -7dB limit was distorted as well.
 
so I rebooted my MOTU and that solved it!  for some reason the MOTU had gotten into some kind of mode where it was not allowing full range output through the firewire bus.
 
So, first I'd say make sure you reboot your Tascam and RME and it wouldn't hurt to reboot the computer and see if that clears it up.  I think it probably IS a power issue, but not necessarily household (120V) power.  it's likely internal where some component has gotten saturated from a degraded resistor or capacitor and is not operating at full capacity.  rebooting will sometimes get it back in the correct working order, sometimes not.

I suppose it is useful to add I used a different laptop in November from the one used last week. In November I used my daughter's, last week I used mine. I have used mine recently with the RME UCX to make a recording at a bar that went fine. It was not sync to other devices that night.

Paul P
Have you looked at the raw tracks in a simple wave editor ?

Yes. I used Wave Shop and it was the same.

All off my stuff works great in simpler setups. I use the Mics regularly. I've made recordings for decades. The problem only happens when running tons of gear and then erratically.

I'm starting to think I need a battery supported power supply.

Thanks for your help, Paul. I'm thinking it's power supply in the house. Garages are often rated to 30 Amps but living rooms can be as low as 15. My gear alone pulls 6 (laptop - 2, tascam 2488 -2, RME UCX, Quad Mic Pre, DBX Compressor and Audient 880 - 2). With all the amps, pedal boards, and the Bose Tower, it's possible we were just pushing the limits on the living room.
 
My 'studio' is on my garage circuit (I'm in a room over the garage) so I've got 30 to play with here and that's why I don't have issues here. Most of the time when I do gigs, I'm recording Acoustic stuff where 8 channels does the trick and this takes me down probably below 4 Amps. It's hard to say what pushes it over and why.
 
It's also just a guess. I'm presuming that the pre-amps are like the environmental frogs that start getting sick before anything else shows an issue. I'm not really sure this should be the case.
 
Again, Thanks for all the help I've gotten on this. I'm totally bummed, because, of course, when I haul my gear across town to make an 18 track recording I REALLY want it to come out!!

 
I was hunting around for a reason a mic's output could be more towards one polarity than the other and came up with two possibilities.  One is if a circuit is clipping one side of the waveform (like a diode clipper) the other is a natural occurance as mentioned in this SOS article :
 
"The other element involved in this is that many acoustic sources inherently have a 'positive air pressure bias' because of the way the sound is generated. To talk or sing, we have to breathe out, and to play a trumpet, we have to blow air through the tubing. So, in these examples, there is inherently more energy available for the compression side of the sound wave than there is for the rarefaction side, and that can also contribute to an asymmetrical waveform."
 
Maybe your mic being close to your amp gets it into this situation, especially when loud ?.  It shouldn't be a problem if the signal half isn't short because it's clipped but rather the other side is tall because it's being blown on by the speaker cone (hopefully not too much so that it causes clipping on that side further down the line).  I can't tell from your pictures if your waveform is clipped on the Cube at guitar=10 or if it's just lopsided.  What do the peaks look like ?
 
Does this only happen when micing a guitar cab ?
 
I don't know what the effects on you gear would be if you approach 15a draw on your household circuit.  If the living room in question is normal, it's outlets are probably on the same circuit as outlets in adjacent rooms, like a dining room or entrance.  So there could be even more things plugged into your circuit.  You have a total of about 1500w to work with on a single 15a circuit so you could add up your equipment and see how you're doing.
 
 

 
http://www.cyberpowersystems.com/products/ups-systems/intelligent-lcd-ups/CP1500AVRLCD.html
 
I don't think this can help with an overloaded circuit.  It has a capacity of 900w for three minutes.  I think it's only meant to keep a computer alive long enough to shut it down gracefully in the case of a power outage or during a very short interruption.
 
If you're drawing too much from the circuit, the only solution is to bring in another circuit.  You could use a 12ga extension from another room, like from a kitchen counter outlet which are normally on separate circuits.  But then you'll risk creating a ground loop by having two different grounds for your setup and having equipment on separate circuits jointed by audio cables (if that happens, you can lift the ground on one end of the audio cable, not the equipment supply ground).
 
 
 

 
I just came across this thread dealing with a MXL Drum Cube Pro :
Strange Waveform from MXL Drum Cube Pro
 
Look at this snare hit :
 

 
Looks familiar !  There's something pretty weird about these mics. They can't take high level in one direction.
 
If you like the sound of the mic, maybe you could still use it for quieter stuff.