ART Tube MP

[mattkw80]

I bought my brother one of those $29 ART Tube MP's for Christmas.

We messed around with it for an hour and a half tonight.

I can't figure out what the OPL button is doing ???

Also - does the +20 button have to be on for all mics, this seems to be the case.

[scrubs]

You might want to read the manual. Also, read up on gain staging.

OPL is the output limiter. It keeps the output signal from clipping. If you turn up the gain enough, it will kick in.

The +20 dB does not have to be on. It depends on the sensitivity of your microphone and how you have the gain structure set up.

[mattkw80]

Originally Posted by scrubs

You might want to read the manual. Also, read up on gain staging.

OPL is the output limiter. It keeps the output signal from clipping. If you turn up the gain enough, it will kick in.

The +20 dB does not have to be on. It depends on the sensitivity of your microphone and how you have the gain structure set up.

Read the manual 3 times. (Well, the little scrap of paper that is supposed to be a manual)

I know what OPL stands for, and is supposed to do.... I just can't hear it happening !

Maybe that's the point, maybe I'm not supposed to hear anything when it 'kicks in' ?

I guess I was expecting to hear some kind of 'pumping' or 'ducking' of the level.

[Robert D]

Yes, not hearing it is a good thing. Rather than listening for it, try looking at your interface metering to see if it's working. With OPL off, set the gain high enough to overdrive the interface, then turn on OPL and see if it is applying limiting so that the audio interface is no longer in the red.
BTW, this is only a test, not a recommended way to operate the thing. The OPL function should be an insurance policy against overs. Headroom is the goal.

[mattkw80]

Originally Posted by Robert D

Yes, not hearing it is a good thing. Rather than listening for it, try looking at your interface metering to see if it's working. With OPL off, set the gain high enough to overdrive the interface, then turn on OPL and see if it is applying limiting so that the audio interface is no longer in the red.
BTW, this is only a test, not a recommended way to operate the thing. The OPL function should be an insurance policy against overs. Headroom is the goal.

I was still able to clip the audio device. (M-Audio Project mix I/O) with the OPL button on.

Oh well, like you said, just a bit of insurance on the output.

I'll just set me levels carefully, and not worry too much about the OPL button.

Thanks for your response.

[songright]

Yeah, but that button looks so pretty, and that vu mater that doesn't do ANYTHING (at least on mine.) They do something pretty special to the sound...especially vocals...I've tried laying down tracks with and without it, and the tracks that have the tube have that sparkle effect. Great sound for the value. Mine first one is over 7 years old now. Just replaced the tube. I take it out live as well.

[mattkw80]

Yeah - it does add a little sparkle.

And it's really nice on Bass.

And the VU meters on this one, also do nothing.