It's always been an issues but I got around it by using a mixer. But there is no way I can hook up a mic direct to the 1800 without it clipping. Even with dynamic mics... volume turned down all the way. is there a trick or something I'm missing. I would like to be able to record without a mixer. 

Sorry, I probably do not understand something...
You connect a mic to let say input 1, turn the gain knob 1 all the way left and you see "OL" lighting when you start singing/playing?

azslow3
Sorry, I probably do not understand something...
You connect a mic to let say input 1, turn the gain knob 1 all the way left and you see "OL" lighting when you start singing/playing?

Yup! :) I know there is a -10db on the back as well but nothing has ever worked. Just too hot! I see and downloaded the latest firmware (2016) last night but the unit function just fine other then the direct line in problem.
"not broken don't fix it" and I found nothing relevant about the update VS. clipping...   

Firmware can not help, the unit has no Digital controllable gain, the part before AD is analog.
Max mic input level for US in the specification is +14dBu (line inputs +20). I do not think there is dynamic mic which can produce it (without amplification). So very strange...
 

Are you sure the input is not a Hi-Z input and/or that you don't have phantom power turned on for a mic that doesn't need it?
 
I am not familiar with that specific interface but those are things that come to mind to check.

I have no idea, I know that I have few options. well two -10db on back of unit and volume controls on the front.
Phantom power is not on. :)
 
Even if I'm using ARC calibration and I plug in the condenser mic I have to keep volume knob to 0 when calibrating.
Also before I realized it was a condenser mic. ha! I was able to calibrate with volume set to 0 with no phantom power on.
Have you ever had one of those days... that lasted for a year or two... ?
 
thanks!
 
  

The us1800 is exactly the same as my us1641.
 
Is this new behavior or has this always behaved this way?
 
 
You obviously tried one of the other front XLR inputs, right. I can see one becoming faulty but not all 8 of them.  
 
For me a Sure SM 58 or 57 will be set without clipping when the channel gain is set between 12 to 1 o clock. 
I have plugged just about everything into every channel of my unit and it has never been an issue. 
Its one of it's strong points is the very flexible input and gain which for me exepts just about any signal from mikes, DI boxes and mixer outputs. 
At full anti clockwise there would be almost no signal at all. 
 
To test is this is not something wrong with the peak light system
Arm a track in Sonar and observe the level for the track, is it overdriven? 
 

Cactus Music
The us1800 is exactly the same as my us1641.
 
Is this new behavior or has this always behaved this way?
 
 
You obviously tried one of the other front XLR inputs, right. I can see one becoming faulty but not all 8 of them.  
 
For me a Sure SM 58 or 57 will be set without clipping when the channel gain is set between 12 to 1 o clock. 
I have plugged just about everything into every channel of my unit and it has never been an issue. 
Its one of it's strong points is the very flexible input and gain which for me exepts just about any signal from mikes, DI boxes and mixer outputs. 
At full anti clockwise there would be almost no signal at all. 
 
To test is this is not something wrong with the peak light system
Arm a track in Sonar and observe the level for the track, is it overdriven? 
 

It has always been that way, the preamps are too hot. I even contacted Tascam right after I bought it (NEW) from SW and Tascam never got back to me... Come to think of it they never have gotten back to me on anything. lol I would like to get away from a huge mixer that takes up half the room but... thanks! :)
 
 
edit: BTW that is with one mic or all channels in use. 

There's something not right, either with what you are reporting or with the device.

Hard to believe that all 8 channels would be defective. 
Where are you setting the channel input level knob? 
And is this with different mikes or just one type?