Stupid question about running valve amps on generators live

mburekenge

I am a total ignoramus on many subjects, but electricity is up there with the best of them.

i have an upcoming gig where the power will be supplied by a crappy generator.

ive played this venue before with my Carr Rambler, and it was a bloody nightmare. As the power fluctuated so did the volume and tone of the amp. Massively.

As I'll be mic'd anyway, would there be any advantage in taking a lower wattage amp like my Victoria 5112, or am I just as screwed either way.

ah the joys of living in a developing country lol

ecc83

The other danger is that the voltage could rise high enough to damage the amp and that is more likely with a lower powered amp than a high one. Our pistol club (when you could shoot pistols!) was on a massive ex R navy genny and we had to keep 2 bars of a fire going to load it. If some bod unplugged it lamps would blow!

I would buy a 500va Variac and a cheap voltmeter and keep it all close by and monitor the supply.

I would also worry about earthing!

Dave.

ToneControl

Can the amp run from a UPS
(Uninterruptible power supply)?
e.g. http://cpc.farnell.com/webapp/wcs/stores/servlet/Search?pageSize=25&st=ups&catalogId=15002&categoryId=700000010270&langId=69&storeId=10180

I bought one at my last house, after the voltage went down to 130V one day, and destroyed the motherboard in my  expensive dual-Xeon  workstation

the better ones have a massive lead acid battery, and if the voltage goes out of a range, they switch to the battery
the bigger batteries will last longer

ToneControl

and I'd be very worried running a decent amp like a Victoria from any small generator, AFAIK it's all dirty power

btw if the battery is big enough,  you can just pull the plug before you start the gig
some of them do have an audible alarm you'd need to disable (beeps) when  providing power from the battery

worth investing in one for your home anyway if you live somewhere that has power cuts

andy1839

I've done a few outdoor marquee gigs powered by generators and used two Joyo battery powered preamp pedals with an AB switch into two PA channels switching between lead and rhythm sounds, with all my pedals on batteries too.  

All in it was about £60 for the Joyos and an ABY pedal, and amazingly didn't sound like a wasp in a box. 
I found using a Line6 M13 multi FX was badly affected by the fluctuating power but the PA not so much. 

I just didn't trust that my valve amps wouldn't come to harm, but that might be me being a bit too precious about them.  

I tried using a Mesa F50 and a Budda SD18 at my first generator powered gig and the budda blew two fuses (hasn't blown one since) and the Mesa sounded terrible. 

mburekenge

Thanks for the input guys... i have a voltage stabiliser in my home studio. I learned the hard way after my useless Furman devices were not man enough for the heavy duty Kenyan power spikes, and fried 16 channels of expensive a/d d/a conversion.

the band manager is speaking to the venue today, and is going to try and get a separate generator for the band... they run the whole venue of a generator so I guess the extra draw from the band was the issue last time. I'll keep my voltguard on for sure!

cheers

ICBM

I would buy an old Peavey Bandit (or another amp from the same series), a Line6 Spider or a Blackstar ID for a gig like this. My experience with repairing various amps that have suffered from mains supply problems is that these three will be immune from damage - and will probably sound more consistent at the gig too. The first two will cost you less than a repair to one of your good amps if the worst happens.

mburekenge

Thanks @icbm. It's a great idea... won't be able to do it in time for the gig though. Just can't get stuff easily here, then by the time you factor in shipping from the uk etc the price goes up again. Maybe i''ll grab one next time I'm in the uk.

ICBM

I also forgot, in Africa they use Roland JC120s a lot for the same reason - that's why they became the 'sound of Africa' - it started when they were one of the only really good solid-state amps... I remember reading that from the guitarist in the Bhundu Boys. See if you can borrow one .

For this gig I'd probably use the Carr and run it in Triode mode, if you don't have any other option - it's less hard on the power valves in case of voltage spikes. Taking the voltage stabiliser is an excellent idea if it will cope with the demand.

ecc83

ID, good idea (and NOT just saying that) The digital and pre amp supplies are regulated and I know the main PA, which is not, will not mind a fair amount of overvolts since they are tested, quite brutally to cope with mains + 10%.

Dave.

ICBM

ecc83 said:

ID, good idea (and NOT just saying that) The digital and pre amp supplies are regulated and I know the main PA, which is not, will not mind a fair amount of overvolts since they are tested, quite brutally to cope with mains + 10%.

That presumably means that the ID60 (or 260) is a safer choice than the ID100, since being the same actual power module it should be able to take about 50% more overvoltage before anything bad happens.

An interesting point about the old Peaveys is that the 220/240 version has a voltage selector, and it's surprising how many I've seen come in set to 220V. Never seen one damaged like that though - I always set them to 240 to be on the safe side of course.

Sorry, slight thread hijack!

mburekenge

Thanks a lot gentlemen. Much appreciated.

mburekenge

I Should also add that the quality of the Kenyan musicians is exceptionally high. Despite using some crap to uninspiring gear, they sound great.

i had a bass player in the studio the other day using a crappy encore bass into a behringer practice amp... he sounded unbelievable in the room. (luckily I split the signal with a Moogerfooger before the amp, and ran it  through a hefty valve preamp and an 1176 into the converters)

im sure that 99.99% is in the fingers... but with my hack like playing,  I need all the help I can get - hence the boutique amps