Help needed

[Daryll]

So I got to the gig last night , plugged everything in like I have done hundreds of times.
Hum from the speakers , quite loud, but independent of channel volume , so I swapped leads , just the same , so I unplugged the VMS 4.1 at hey presto , just the normal slight hiss from the speakers , so I unplugged the USB from the laptop , plugged the VMS back into the crossover and loud hum again , so guess I have a faulty VMS , got through the evening on the left channel only , no sub , just the one top and the Horizon 1300 amp , and I had to put up with the hum , no one noticed in the pub ,I was surprised how much bass I could eek out of the 8" tops , no either the output stage of the VMS has a fault , of something else , I will try the booth output later , failing that I new controller is needed ASAP.
Your thoughts ans suggestions are welcome.

set up is as follows.....Laptop....VMS 4.1.....crossover......Horizon 1300 ( tops)......berry EPQ2000 ( subs)

Cheers

Daryll

[Excalibur]

Sorry to hear that. Without sight/sound of the problem, it's basically guess work.

All I can suggest is trying to replicate the fault, and remove it by elimination. I would not be amazed to find it works perfectly today at home.
Sometimes, faults are related to venues. Earth loop somewhere? My Proels have an earth lift which can be invaluable.
Check the VMS power supply perhaps? Good luck, keep us posted.

[DazzyD]

Like Peter says, without being there and seeing the fault first hand then it's pretty much guesswork. You need to work out which item in the chain is faulty. Can you run a different setup that allows you to take individual items out of the chain to work out the faulty item? If not, is there any way you can incorporate a ground loop isolator or DI box in your setup as this may help?

[Daryll]

Thanks guys , I am off down the garage to "set up" and trace the fault , if all else fails there is a nice Denon MC 3000 for sale not too far away , plus I have just ordered some phono to XLR to try the booth output , and two TSR jacks to XLR in case I get the denon, more annoying than anything else.

Cheers

Daryll

[Daryll]

Well this is embarrassing , I have a simple DMX controller , just for weddings , first dance , slowly rotating white gobo , with a transformer ( see where this is going.....) , the transformer looks almost the same as the transformer for the VMS 4.1 , however they are not interchangeable , so a quick swap and taa daa , one fully working disco , I need to see my roadie and explain the difference.....

Cheers

Daryll

[Excalibur]

Embarrassing, but simple and cheap to fix!

Check the VMS power supply perhaps? Good luck, keep us posted.

The non-interchangeable transformer is not unheard of, as you've found out. My two ways round it are to put the power supply for my VMS in the bag with the laptop. Secondly, both VMS 2 AND 4.1 use the same type of transformer, and I carry a spare.

From my experience, these controllers can throw up some baffling and annoying faults if the power supply isn't plugged in, which is why I suggested checking there.

I don't know what a s/h MC3000 costs, but personally, I'd look at a VMS 5 first. It's a combination of the best bits of the 2 and 4.1, and I want one. Can't justify it, but I want one.