Fireface 800 distorting

Hi,

This has been driving me nuts for a while.

I use a condenscer mic w a power supply, going into a custom tube preamp, connecting w a trs cable to an older fireface 800 that was modded by black lion audio. i have tried connecting the preamp to the fireface in different ways but was advised to go quarter inch to quarter inch into the line level in the back of the fireface. but no matter how i connect the preamp to the fireface (even putting lo gain setting in fireface software), i am getting distortion on my mic signal, even when the wav is lower volume (or not going into the red on the meter on my daw). I'm a musician, not a studio engineer.

I sent the fireface to the repair shop and they found nothing other than repairing something which was causing clicking. i sent the mic back to adk two times across the country. they fixed the capsule the first time but the second time found nothing. i just had the tube preamp serviced w new tubes.

i have plugged the mic directly into the fireface and it does the same kind of thing. the signal just shoots up into the red. for lack of a better term, the sound has no "dimension" or lift. like no brake pads or shock absorbers on a car.

can it be the power supply in the FF? the capacitors? they would have found that at the rme repair place i guess.

i have a lot of projects in the works. i'm singing good vocals that sound distorted. started happening about 3 or 4 months ago.

maybe if i took the FF and ran it over w my car a few times, that might fix it? maybe a sledgehammer?

i'm going to make a few more calls monday, and an engineer friend maybe come in the next few days to look.

any thoughts? I know it's an older device that uses firewire, but it was giving me real nice dimensional vocals.

thanks,

Paul