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.

I want to add that the various channels do not have a problem at the same time and I only have issues like this when mobile... away from home... and recording sixteen or more channels while a full band plays. What are the symptoms of not enough power? Do the preamps starve first?

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.

Thanks Beagle! It is so strange it occurred both on the Tascam, which writes it straight to its own hard drive, and from the RME which sends it over USB to the computer. It seems unlikely for the two items which are sync locked but otherwise independent to give evidence of the same problem. Unless the problem is somehow global in nature.

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.

 
There are a lot of variables in your setups.
 
Have you made some sort of table/grid listing all of them ?
 
So far it looks like you've used different mics going into different preamps going to different recorders and have had problems in all cases.  There has to be a common denominator somewhere.
 
Have you looked at the raw tracks in a simple wave editor ?
 
Eliminate as much as you can from your setup.  Have you tried to reproduce the problem with a simpler setup ?  You may have to set up everything again as it was, see that the output is wrong, then remove or swap things until the problem goes away.
 
 
 

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.

 
I can't see you making progress with this if you can't reconstruct a setup that causes problems.
It could be anything, and probably something you don't expect.
 

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!!

 
This image shows that the guitar cube mic really can't handle volumes. I was using my Fender 4x10 DeVille and the SM57 handled it fine but the Guitar Cube couldn't handle it at all.
 
Now with the guitar at 3, the Guitar Cube did ok.
 
I next recorded a Shure SM86 condenser to compare with the guitar cube. The Shure did fine, the guitar cube did not.
 
I flipped the channels the mics were plugged into and the same result, the Guitar Cube was a problem.