Qu-16 questions and help

[kngaParticipant]

Hello!

1.) We are band playing, and when we do our soundcheck we Multitrack record, and then play back so we can listen what it sounds in front of speakers. As I have 2 keybords pluged into ST1 and ST2, when I played back multitrack recording, those two channels didn’t heard (Yes, I changed Preamp from Local to USB). And when I do that, on ST2 colour in preamp section goes blue, but it says X, not USB.

2.) We use Qu-pad to MUTE FX between songs, when singer is speaking. Our guitar player mutes it. I have CUSTOM 1 layer opened, just with FX section to mute it. But it’s a bit problematic because MUTE button is small and sometimes hard to press it normally. Can I change this somehow?

3.) I also use Qu-pad on Ipad 1 to EQ and stuff, but I often have problems with connecting with mixing console. I have DHCP enabled on Qu-16. Ipad 1 often doesn’t find Qu-16 when I try to connect, so then I turn router off and on again, or plug ethernet cable again, and then it somehow works. Are there any suggestions on how should I make it ready at first try? Do I first turn router on, then connect ethernet cable with Qu-16 and then enable DHCP, and at last try to connect on Qu-pad? How do you do it?

4!!!.) Yesterday I had first accident with Qu-16. Our double bass is connected to small Boss GEM7 equalizer, and then to mixer. Always when I plug in/out jack cable from GEM7, channel goes CLIP, even though GEM7 is turned off. Jack cable is also very sensitive, if I touch the end of it, channel goes CLIP (I tried different cables, but it’s same). So yesterday I pluged jack cable out of double bass, and jack cable fell down on the floor, but I didnt look at mixer, and channel was in PEAK all the time (I guess several minutes, before I noticed). Today I compared this channel to others, and it sounds exactly the same and also signal is amplified same as on other channels. So, how can I know that channel wasn’t harmed? And what can I do to prevent those things to happen again? We were playing in strange place, electricity was bad, microphones were shocking us when we touched it with mouths, small equalizer was shortly turning off/on (the light was blinking). Was this a problem?

Thank you for your help a lot! I hope I didn’t destroy preamp on one of my channels!

Greetings, Alen

[cornelius78Participant]

1: Are you using USB-A (socket on top of mixer: Qu-Drive) or USB-B (socket on back of mixer: multitrack streaming to/from computer with running a DAW?) The Qu-Drive is limited to 18 channels, which you might have as your 16x mono + ST1 which would explain why you don’t get anything on ST2.

2: Perhaps put the FX rtns (or sends) in a mute group and mute it from a softkey? I know the button is not really bigger, but being in a different location on the iPad’s screen with a bit more space around it might help.

3: If you’ve got the router acting as DHCP server you’d turn that on first so it’s ready to start handing out IP addresses. Then turn on the Qu so the Qu gets an IP address from the router. Then you’d turn on the iPad so the iPad gets an IP address from the router. Then launch the qu pad app. If on the Qu you go into Setup>Control>Network you can see the IP address, subnet mask and gateway that the Qu has been assigned. If you go into the iPad>Settings>Wifi> and tap the blue arrow next to the wifi network the ipad’s connected to you’ll see its IP address, Subnet Mask and Router assignments. The numbers for “Subnet Mask” and “Router” on the Ipad should match the numbers for “Subnet Mask” and “Gateway” on the Qu. The IP address should have the same numbers for the first 3 octets but the last numbers should be different (eg “192.168.1.5” and “192.168.1.6”) If for some reason things aren’t matching up like they should you can renew the IP lease on the iPad, turn things off and on again etc.

An alternative would be to disable DHCP server functionality on the router and DHCP client functionality on the QU and iPad, then manually assign IP addresses to everything. As long as everything is on the same subnet mask (255.255.255.0, assuming you’re using 192.168.1.x for your IP addresses,) and the Qu and iPad both point to the router’s IP address as their gateway/router then it should be fine. TBH this is my preferred method: there’s less chance of something going wrong. Then, as long as the QU, the router and the iPad are up and running with network connectivity before you launch the Qu-Pad app, the app should be able to see the Qu.

4: Re jack cables: the reason for the clip when you plug it in and out is because of the arrangement of the T(R)S on the cable and the socket. As they’re all in line, as you plug it in/unplug it there’s a moment when you end up with the active tip touching the earth sleeve, which is what creates a pop and can (depending on how hot things are) clip an input. This is one reason why I like XLR arrangements: 3 separate pins means as long as the cables wired properly this doesn’t happen.

Re clipping and damage: in theory it’s possible to damage a preamp by putting a signal that’s too hot through it (eg the output of a several thousand watt poweramp directly into a preamp would not end well; I know it’s an extreme example to illustrate a point, but I’ve seen it done before. A drummer unplugged the input from his passive floor wedge (which was unfortunately on a TS socket, not Speakon, and plugged it into his IEM beltback. He didn’t realize the signal was speaker level, not line level, and he fried the beltback. Thankfully he didn’t have the buds in his ears at the time.) From what I’ve read though you’d need a reasonably hot signal (eg a poweramp output) to permanently a modern preamp.

If you want to test your preamps, grab a signal generator (or any source really) and y-split it to two preamps (a working one and the potentially-not-working.) Turn the gain up on both channels so the gain pots match on the touch screen (eg 9 o’clock seems to be 6dB,) ignore the meters. In theory the meters on both channels should be the same if both preamps are working properly. If you want to be a bit more accurate, you could then pfl the channels one at a time and run a multimeter over the phones socket. If the multimeter shows both channels being the same, then either both channels are fine or they’re both broken.

For preventing this in future, one rule is to have everything plugged in before you turn anything on. Then when you do power up, amps/active speakers get turned on last. For turning off, do the reverse: amps off first. Obviously when plugging things in on an individual basis it’s the channels should be muted, especially if +48V is involved. Finally, Neutrik make a “Silent Plug” that uses a magnetic switch that mutes the plug when it’s being plugged in/unplugged, which I’ve heard good things about.

Re Venue’s dodgy power: there’s not much you can do if it’s not your venue. If you’re being shocked when you touch a mic there’s an earthing issue somewhere. Older buildings, especially those that have been converted, eg an old warehouse to a club, can be all over the place in terms of wiring. Try to keep all your audio gear on the one circuit, and try not to share circuits with things like air conditioners and old dimmer racks. Invest in a power conditioner to stabalise voltages (especially important with digital gear: I’ve read of certain digital amps outputting digital noise at 0dBFS when the input voltage dropped too low.) A UPS is probably useful too.

Sorry for the essay, HTH.

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