Equipment issues - venue power?

Cols

Various technical problems during my last gig; the 6 button footswitch for my Marshall DSL stopped working, and the other guitarist’s EHX Synth-9 pedal refused to function.  Not a complete disaster, but it did need a bit of swift replanning.

Tried everything again at home and it’s all working fine.  The venue was a lovely and very ancient pub; is it possible the venue power could have caused this?  Everything else running off the mains - amps, PA, lighting - was fine.

ElectricXII

I don't know about your footswitch, but EHX 9 series pedals (I've had a B9 and have a C9) can be very picky about what power you give them. So much so that I don't power my pedal from my T-Rex Fuel Tank, and use the EHX wall wart instead.

Stratavarious

Check cables…

Cols

Stratavarious said:

Check cables…

Yeah, second thing I tried after “Maybe if I switch it off and on again”.

Danny1969

Unlikely to be the mains supply IMO, more likely just a combination of the DSL flaky switching system and a fault with the EHX  or the supply to it.

Most low voltage devices (inc the switching circuit in the Marshall) can easily handle variations in the mains because the supply is internally regulated voltage wise and has reservoir caps to keep the supply steady. 

Cols

The key things here are:

1.  Two pieces of unrelated equipment flaking out
2.  Both working perfectly again when tested later at home

One of them throwing a temporary hissy fit would be explicable, but both conking out AND then showing no fault back home is a bit of a coincidence.

Danny1969

Cols said:

The key things here are:

1.  Two pieces of unrelated equipment flaking out
2.  Both working perfectly again when tested later at home

One of them throwing a temporary hissy fit would be explicable, but both conking out AND then showing no fault back home is a bit of a coincidence.

I can see where you're coming from but DSL channel switching circuits often go intermiitent and generally then completely faulty. I've repaired a few myself. Even some DSL's used at home that have never been gig'ed often go wrong. Shame because they are good sounding amps but that channel switching system is over complicated and prone to problems.

The EHX I have no experience of but any professionally designed piece of gear can handle fluctuations in the mains supply. If the mains had stopped completely then the heavier current stuff like the PA would have been the first to complain and go off.

Nothing actually runs on the raw mains supply in principle except things like electric kettle elements and washing machine motors. All actual electronics runs on rectified,  smoothed and regulated DC voltages derived from the mains. A lot of equipment doesn't care if the mains voltage drops to 120V .. it adjusts the width of the pulse width duty cycle to keep the output voltage the same. So your laptop charger is happy on 120 or 240 etc .. laptop still gets a steady 19V. Something with a linear supply has an input voltage to the regulator that's  higher than the wanted output voltage. Then incoming mains voltage can drop a fair bit before the regulator can't maintain the wanted output voltage

You can get spikes on the mains which can cause noise on digital circuits, and that can cause the old glitch but stopping working completely like you said generally means the mains has stopped completely for some reason. Had it done that then the rest of the gear would have gone off as well. I have seen a digital desk be damaged by the mains going off while operating but that was because it was an early one with a hardrive. 

ESBlonde

The Key9 and MEL9 are susceptible to noise if not run on an isolated power supply, they are useful. But I’ve not experienced problems of them not working at all.

maltingsaudio

Wouldn’t like to comment on the synth pedal but my thoughts on the dsl pedal is probably down to some dirt or condensation in the jack connection, the voltage on the switching is so negligible , and the power for the pedal is supplied by the amp which I assume worked ok ,the house mains is unlikely to affect it. Probably the journey home being g in the warm  and a stout re plugging cleared the fault.

Cols

That could be it, it was a cold night.

Just for some extra detail - the behaviour was that when the amp was on standby at the gig, the footswitch worked normally.  As soon as I turned it on (half power or full power, made no difference) the lights went off on the footswitch and it wouldn’t work to change channels or anything else. 

Danny1969

Cols said:

That could be it, it was a cold night.

Just for some extra detail - the behaviour was that when the amp was on standby at the gig, the footswitch worked normally.  As soon as I turned it on (half power or full power, made no difference) the lights went off on the footswitch and it wouldn’t work to change channels or anything else. 

That sounds like the amp has a fault. You might find it's fine some nights, sometimes it's not. In my experience the channel changing circuit plays up a bit now and then before it stops completely. There are different models of DSL so the circuit varies a bit so this is a general description of what I've seen.

I hope I'm wrong but in meantime forewarned is forearmed as they say.

oh_pollo

Cols said:

 

The venue was a lovely and very ancient pub;

Could be electrical. Could be ghosts.

Cols

It seems to be a known issue.  The footswitch works with a chip which needs to communicate with another one inside the amp; the mono cable carries DC power to the footswitch and a digital signal communicating between the two.

Oddly, the solution seems to be a stereo cable.  No-one knows why.

https://marshallforum.com/threads/marshall-dsl-40cr-footswitch-problem.118621/