Hi,

I will be recording very loud sounds with high SPL microphones which have a pretty hot output. I was wondering if i turn the gain all the way down would the pre amp still clip before the gain staging yet show that the signal is bellow 0dbfs on the meter.

What I really asking is if my meters show that the signal is not clipping with low gain settings, could the pre amp itself clip before the gain stage?

I am aware of using pads to reduce the gain before the preamp however is it really necessary if the gain is very low showing a low waveform?

I hope that makes sense

I used a MXL Gold 35 on a jazz BD and it over loaded the mic pre of my SD788T. I could not turn down the gain enough to get a clean signal. It was a fairly quiet BD. The meters did however show the OVER Load.

Thanks very much, that makes sense. However I wonder if distortion is still possible if the meters are showing a signal below 0dbfs

What mic are you using?
The 788T's meters seem good. The RING always flashes red at -1db and above, if set that way. Otherwise you can set it to flash red even earlier. That is not distortion though, only an indication that the signal has hit that level. I run my 788T up to inside the -1db and it is not distorted.

On the 788t, you can set the Inputs to Line Level and still turn on the 48V Phantom for the input. They did this specifically for high SPL signals

if the levels show below 0dB you should be OK. Most preamps actually have some gain even at the lowest setting.

If it does, the distortion is probably taking place at the microphone, in spite of the high spl spec.

That's good to know. THANKS

I have cmc 6's that were right up to a trumpet and they had a severe dc offset from high sound pressure I think but am not exactly sure why.

Like others have said before:
If you set it to line + P48 it's impossible to overload with mic signal. If it sounds distorted with that setting it's because the mic itself can't handle the SPL.

BTW: The level meters show the post-pre-amp level that goes to the tracks and you can set the 788 so the rotaries control the pre-amp gain and not the fader level (which controls the level that goes to your track). Make sure you set that right otherwise you might be overloading the pre-amp even though your level meter is low or totally fine.

The colored ring will turn red when your pre-amp level is overloading. Orange shows limiter activity. Green means level below limiter threshold.

You'll find details in the manual.

Waveforms from brass instruments are often asymetrical, sometimes wildly so. It's just the nature of the instrument.


If it SOUNDS distorted but your level is not near clipping on the mic preamp/recorder, then you are distorting the output electronics of the microphone.

Actually it wasn't distorted at all, it was asymmetrical with the top half having a lot going on with the bottom half showing hardly 50% of the waveform height.

Totally normal.

The picture of that waveform got distributed to both the mic and recorder manufacturers. Everyone at the time was stumped

Nice to know THANKS

I've noticed it on trumpet and trombone many times over the years.

Sound Devices would be stumped because they specialize in audio for video and don't do as much music; Schoeps would be stumped because they're more analog people who don't spend much time looking at waveforms.