Mains power and L1 model IIs

Hi Guys,

I wonder if a tech-head can help me explain a sympton suffered by a UK based L1 model II user?

My customer suffered a complete drop in volume from two model II systems while performing at a showcase gig yesterday. After a few moments both units came back to life. Both L1s were being driven hard and the analogue input led was occassionally flashing red. The L1s were being fed a signal from a Mackie CFX12 mixer.

The customer and I had a chat and it became apparent that both L1s were being fed from the same mains socket which should deliver 220volts/13amps here in the UK. The three keyboards, mixer, minidisc player and guitar pedalboard were also fed from the same mains source and there were a further six bands/acts in the venue and probably on the same mains ring.

Could it be that the loading on the mains would have caused the L1s to suffer a mains related issue and a drop/cut in signal? Both L1s are fine today at the customer’s home and have been fine previously.

Any thoughts gratefully received!

Best wishes, Andy


I think you have it correct. The circuit probably became overloaded, the mains voltage dropped down, and the L1’s did not have enough power to keep going playing. For this to happen, the voltage needed to be in vicinity of 185 volts, or 20% below the usual mains voltage.

All the bands probably hit a note at once which drew a lot of power, dropping the mains voltage for everyone on that circuit. I would not be surprised of other bands had similar problems with their gear.


Hi Andy,

Is there any chance that there was a sound-pressure-level based limiter on the mains socket?

Hi Andy, thanks for posting my problem…There was no sound limiter at the venue, we pushed the L1’s at the sound check and one side cut out when it was driven hard, but the other side was ok, however, when it came to the performance,I turned the volumes down and as soon as we started playing our instruments-guitar and keys, the 2 L1’s cut out immediately, we tried again and I took the sliders down a touch again!!at this point the led’s on the L1’s were only in the green…and they cut out another twice…3 times in total!! Yes we were all on the one 13amp plug…??

All thoughts appreciated, this was our first public performance with the L1’s and has severly dented our confidence in them…I know how to set them up…a bit mystified here??



Hi Miles,

The other issue we haven’t yet raised on the forum was the total loading on the 30 amp ring main.

I recall you mentioned that as it was a showcase event there were a number of other bands in the same room. If they were all plugged into the same ring main then the total availability of power would be affected, hence the use of separate 32 amp or 64 amp three phase outlets outlets at bigger gigs.

You might also have been plugged into a spur off the ring, which, in essence is like a mains extension lead buried into the wall. Some or all of the other bands might have been on a ring but if say, you and another act were on a spur, and you needed more juice than they did, this could explain why the other acts did not appear to suffer the same issues.

In my experience it is surprisingly easy to overload domestic mains especially if lighting rigs using PAR 56, PAR 64 etc lamps are brought into the equation.

Are the L1s OK now?

Best wishes, Andy

Hi Andy, was going to try them out this afternoon as Jenni has a solo gig tonight. But if from what you say that its a mains power issue then hopefully we can learn from this and count our blessings that it wasn’t a corporate gig where the clients are not so understanding…! We were positioned in an “L” shape,and we were at the end section of the “L”, consequently the 4 other bands were more along the front of the hall and had a seperate “power supply” the ones with the big blue sockets…64 amp or something?? So we shared our power with another band on the “normal” ring main…all things considered when you analyse it, it’s a wonder we never got “fried”…just got to be realy careful about the power supply in future me thinks??

Kind Regards