Signal "gate" on L/MONO?

[mpderksen]

I'm the Bass player at a new church, and they asked me to help them set up their sound. They have a Stage4 KB, goes to a DI box - XLR to the snake, to the board. I plugged a TS 1/4" -> XLR cable into the L/Mono port in back. The only way to get tone/signal was to hit the keys pretty hard. (I think this is called "velocity"?). If I imagine hitting a key soft=1, and REALLY hard=10, I have to press at about a 5 to get a sound. Less than that, it's dead. Harder than that, it's no louder. 5-10=sound, 1-4=zero.
It's like there is a noise gate that required a certain velocity before it sends a signal.... I'm familiar with active/passive basses, but that's just a volume/db correction, not a complete cut off.
We "fixed" it by plugging into the Phones port instead. While it's technically working, I don't like the idea of not having it correct.
I don't have it with me, so I can't really check anything until Sunday, like which software version it's running.
Maybe this is at the board and the L/Mono puts out a lower signal that isn't meeting a required threshold?

If I left off any details that can help you help me, just let me know.

Cheers,

Michael Derksen

[gitarrenzupfer]

Hello Michael,

from a technical point of view, I can only think of one explanation for the behavior you describe (several factors come into play):

1. The mixer probably actually has a gate activated on the channel (did you check the "velocity" with the Keyboards Mastervolume fully up/down ?)
2. The DI box used attenuates the signal significantly (possibly even with -20 / -40 db pad switches engaged)
3. The headphone output is significantly louder compared to the line outs, therefore above the threshold of the gate, which is maybe why it "worked" like that.

So I would check the following at the next gig:

1. Mixer - Gate activated (maybe there was a hum problem with asymmetrical connections in the past)?
2. check Pad switches on DI box activated (possibly also check gain on the mixer)

Good luck...

[mpderksen]

This is helpful, if I may tag a follow-up question to your reply?

I did check the DI box is at Zero attenuation.

If you can describe how to check the velocity on the keyboard for that channel? (I suspect this is a potential solution). I am unclear how to compare the relative signal output from the L/Mono vs the Phones. I downloaded the manual, but it's massive and I'm not sure what I am looking for.

Can I plug a basic TS instrument cable from the KB to my bass amp and see if I get a signal? That would isolate the mixer/board, right?

Hello Michael,

from a technical point of view, I can only think of one explanation for the behavior you describe (several factors come into play):

1. The mixer probably actually has a gate activated on the channel (did you check the "velocity" with the Keyboards Mastervolume fully up/down ?)
2. The DI box used attenuates the signal significantly (possibly even with -20 / -40 db pad switches engaged)
3. The headphone output is significantly louder compared to the line outs, therefore above the threshold of the gate, which is maybe why it "worked" like that.

[FZiegler]

What OS is your Stage 4 on? The first versions had an issue IIRC where the two channels had an inverted phase. If you sum that up into mono (with the mono button), you'll erase almost everything. (edit: which will result in a very low, hollow signal; it's line level nevertheless and may have a very different level with sounds that aren't very symmetrical)

Update the instrument to the latest OS.

And check if - when playing out mono - the better result is not to sum the two channels up but to just connect one and leave the instrument in stereo mode.

[gitarrenzupfer]

Can I plug a basic TS instrument cable from the KB to my bass amp and see if I get a signal? That would isolate the mixer/board, right?

Yes, but be careful 'cause your bass amps input isn't build for line-levels (turn down your gain knob) !