I am back with another problem

During my gig last night i lost sound on 2 occasions - the first was the worst where i had to reboot my laptop!

Half way through my gig - As soon as i switched on a light
via my lighting panel (prolight power panel - i have 2 of these which i connect my lights to via IEC sockets)
http://www.djstore.com/item/lighting_control/procont05.htm

I lost sound!!

There was no noticable power loss on any of my equipment - the only thing that happened was i lost USB connectivity to my Vestax VCI-100 midi controller, however when i tried to change a track with my mouse, nothing happened (no sound) which tells me the NI audio kontrol also lost usb connectivity -
rebooting my laptop solved the problem -

The second occasion - (whilst using the remote of my smoke machine to push out some smoke) i lost power again, this time it was easier to recover as i pulled out the usb of the Vestax and i recovered!

To be honest this incident has really upset me as a) this has never happened before b) i have invested in some pretty good gear and ensured that things like this shouldn;t happen.

the rest of the evening was a damper as i was so paranoid that i would lose sound again i was to scared to turn on/off any more lighting effects!!

To summarise
- The amp and general power of all of my other devices did not show up as having any problems
- I don't know if it is coincidental but each time this happend i was turing on/off a light with my prolight power panel).
- both times this happened it seemd to blow out USB connectivity to my laptop?
- on the laptop side i use a macbook pro with a NI Audio Kontol soundcard which in my opinion and experience are the most reliable pieces of kit on the market (in the laptop dj arena)

the venue was a school hall - i plugged my equipment into normal mains (as they don;t have dedicated sockets for Dj's etc)

Any ideas guys???


p.s.
the most annoying this about this is i played the same gig (school disco), same time last year, with a crappy laptop, direct connection to Cambridge audio home amp, still using the prolight power panel and a cheap usb mixer without any problems whatsover - now i have invested 3k into my setup this happens.....

Maybe the switching panel is causing spikes!
Do you run all the sound gear on the same supply/extension as the lights?

Jim

Always best to run the PA and lighting on independant supplies...

It sounds like a voltage drop that caused the USB to momentarily loose connection and some progs like otsav need to be rebooted if they loose a device....

Other than that got me stumped....

Nik

One tip is to have the laptop battery in situ during gigs then if you lose power momentarily the battery will take over.

A couple of weeks ago I lost power twice during the evening - only for a split second and on the 2nd occasion I noticed one of the waiting staff tapping his foot on the wall just above the socket - yep a dodgy wall socket. If I hadn't had the battery in I would've had to reboot the laptop.

The only thing you need to do is run the laptop at home between gigs to drain the battery and then recharge it during the next performance. If you don't do this then the 'memory effect' comes into play ie if you continually charge a fully charged battery without allowing it to drain occasionally it won't hold the charge for very long.

You are correct Paul, but this does not help any self powered USB devices and hubs...

Thanks for the advice guys.

In answer to some of the questions & recomendations -

I use the same power source extension lead for all of my equipment - In future i will use 2 - 1 for sound and the other for lights.

I always have the battery in the laptop and ensure that the laptop is fully charged before gigs and also ensure that the battery is working, i don't believe loss of power to the laptop should affect USB connectivity when the battery automatically kicks in, but in the wonderful world of computers, anything can happen i suppose!!!

Check your power settings for your laptop, when it goes on battery it may disable your usb ports.
I know by default mine disables the ethernet port.

Also when you start using 2 extensions try to plug them into different outlets (not the same twin socket).

Jim

Noise in the power was causing the USB Devices to disconnect..

this then also caused your software to get all upset

and this forced you to reboot the laptop mid gig...

If you visit staples or PC world you can get a UPS for about £50 or a more expensive one with better mains filtering..

Use one of these with all your computer devices to keep them safe from this kind of problem..

Switching mains often causes spikes on the mains which upsets some equipment.

Otehr than running noisy equipment on one mains socket and the rest on another you could buy a filtered extension lead for your PC. They are cheap enough and would be cheaper than a new PC !

Nigel Electronics Engineer.

Is the smoke machine powered through the IEC switch pack aswell?

No, the smoke machine was the only effect which was connected directly to the Extension lead -

It may have been a weird coincidence but as soon as i hot that smoke (remote) button - my sound went!

Sounds to me like its an issue with the way the things are plugged in (as already said)

The only advice i can offer is -

Plugs your lighting and smoke machine into one extention lead

Mixer cd player etc in the other


Many many years ago, i had a problem when the smoke machine was used it clicked through the speakers - This was resolved by changing the way i wired things up - lights in one extention etc.


Id try that first and update us afterwards.

Hi All, first time posting

A similar issue happened to me when i hit the smoke machine whilst doing some school discos at Christmas - it caused the power amp to give out a massive buzz/mains hum on the right speaker and then cut out with its Protect and Clip lights permanently on. It also smelled as if it was burning. The smoke machine was even plugged into its own extension and in its own socket (separate from other lights + amp, etc).

Actually I ought to find out what happened to that amp (its owned by the school), as it was sent away at the end of December under warranty (less than 2 months old at the time). I'm running on my own backup amplifier at the moment.


David

This is classic mains noise going into the amp.
Its down to cheap and poor design of the power supply in the amp.
I put 100nf capacitors across the big electrolytics to stop this problem.
The big electrolytics are inductive at high frequencies and so let spikes through and this can destroy transistors or even otehr components.