vintage ampeg gear supposedly blows FOH generator at festival

[belgamrood]

hi



i have a question for you guys, let me sketch out the setting first



im from belgium, mains are 220V here

i play in a band, and we play exclusively ampeg

i play bass on a 78 SVT and my guitar player has a 78 V4B

both amps have internal conversion to 220v, i don’t need external transformers/supplies etc

last weekend we played on a outdoors festival

halfway through our set the whole marquee fell without power

everything but the lights on stage went out

needless to say this sucked big time

all our amps went off and we were left with no sound

the organization later told us it was because of the old amps we play

some interference with the generators

i have to say this was a medium sized festival, with two stages, about 5000 people attending

i don’t know the specifics of the generators they use

anyway, after 5 minutes the power was back on and we could continue our set

the amps were working flawless as before



at no point did any of our amps blew their fuse, they were intact

i would think that if theres a shorting in the amp, the power would keep falling out on the festival?

its hard for me to believe that this gear, that has been working since 1978, all of a sudden now makes problems for the electricity at this festival?

i keep my amps serviced by an oldskool tech that puts a lot of love in them, everybody that matters in the music scene goes to this guy, the pros and the hobbyists, for this reason. he knows his poopie



is there a way i can find out if it was my gear?

if so, is there something i can modifiy/change so this not happen again?

if not, is there a way to find out what the problem was?

the festival tech mentioned something about vintage amps giving huge peaks. i find this hard to believe. if a band like SLEEP can play live through quadruple stacked SVT’s and 3 fullstack green amps, ALL TUBE, and have no problems whatsoever, why would a standard setup of 1 SVT and 1 V4B give troubles



ive been bummed out for a couple of days, because i love the vintage tone, and i love my classic gear

i had an `SVT VR and a reissue V4B and sold them both in favor of my vintage gear.



looking for any knowlegde/help on the subject





best regards

filip

 

[P-oddz]

It sounds to me like the fault of the festival and their generators in place. I wouldn't worry about your gear suddenly being the culprit of electrical surges just because it's older, that sounds really flaky to me.
I would guess they just overloaded their supply.

 

[two fingers]

Anything I can think of that would have tripped anything on the generator would have also blown (at least) a fuse in the amps if the amps were the culprit.

My gut feeling is that the explanation you were offered was ridiculous.

 

[bobcruz]

I don't know a thing about electricity but I know BS when I hear it, and what they told you was pure BS:

 

[Old Garage-Bander]

hi



i have a question for you guys, let me sketch out the setting first



im from belgium, mains are 220V here

i play in a band, and we play exclusively ampeg

i play bass on a 78 SVT and my guitar player has a 78 V4B

both amps have internal conversion to 220v, i don’t need external transformers/supplies etc

last weekend we played on a outdoors festival

halfway through our set the whole marquee fell without power

everything but the lights on stage went out

needless to say this sucked big time

all our amps went off and we were left with no sound

the organization later told us it was because of the old amps we play

some interference with the generators

i have to say this was a medium sized festival, with two stages, about 5000 people attending

i don’t know the specifics of the generators they use

anyway, after 5 minutes the power was back on and we could continue our set

the amps were working flawless as before



at no point did any of our amps blew their fuse, they were intact

i would think that if theres a shorting in the amp, the power would keep falling out on the festival?

its hard for me to believe that this gear, that has been working since 1978, all of a sudden now makes problems for the electricity at this festival?

i keep my amps serviced by an oldskool tech that puts a lot of love in them, everybody that matters in the music scene goes to this guy, the pros and the hobbyists, for this reason. he knows his poopie



is there a way i can find out if it was my gear?

if so, is there something i can modifiy/change so this not happen again?

if not, is there a way to find out what the problem was?

the festival tech mentioned something about vintage amps giving huge peaks. i find this hard to believe. if a band like SLEEP can play live through quadruple stacked SVT’s and 3 fullstack green amps, ALL TUBE, and have no problems whatsoever, why would a standard setup of 1 SVT and 1 V4B give troubles



ive been bummed out for a couple of days, because i love the vintage tone, and i love my classic gear

i had an `SVT VR and a reissue V4B and sold them both in favor of my vintage gear.



looking for any knowlegde/help on the subject





best regards

filip

I agree with everyone else that the venue either was trying to place blame on you or they are just clueless about electricity.
The only difference between new gear and vintage gear is that the vintage gear, if it is tube equipment may need more power from the generator than solid state gear. But this is not your fault.

The venue did not properly size the generator for the job.

Regardless of new gear or old, they should properly size the generator and breakers on each branch of the generator circuits for the expected total power usage, and then they should have at least twice that capacity.

What probably happened is that someone else came along and needed power and plugged into the generator thus overloading it.

Old gear does not do anything to the circuit where it is plugged in that newer gear doesn't do, except for tube vs solid state current requirements.
What would have been their excuse if you had a brand new tube amps plugged in?

 

[Al Kraft]

My guess would be that these folks are used to sizing their generator/power requirements for the newer generation of equipment which frequently draws less power. Without making this a class this vs class that discussion, I think we can all agree that class D amps operate at higher efficiency and draw less average power than the older generation equipment required to produce similar SPLs.

Knowing nothing more than we do at the moment, I would say the organization was simply trying to play offensive ball and place the blame on you before you had a chance to ask why their power capacity was insufficiently sized and placed your equipment in jeopardy. As long as your gear works fine now, I wouldn't put too much stock in what the organizers said.

.

 

[Geri O]

Short and simple answer (from a guy who techs generators for live production shows when the so-called "generator tech" can't be found)...

The fault was not with your equipment. Period.

Whomever is in charge of the generators is an idiot or they are idiots, whatever the case may be.

For the typical festival requiring generator power to even happen, there's far more power-hungry devices and requirements than your vintage tube gear.

Stop being bummed out. Right now.

The end.

 

[belgamrood]

thanks everyone for the replies

i think im gonna have a chat with the organisers

 

[Old Garage-Bander]

thanks everyone for the replies

i think im gonna have a chat with the organisers

If you can, you might want to have their electrician there to explain how he came to the conclusion that everyone would be using solid state amps, and how he arrived at the generator load without inquiring about the equipment that was going to be used.
And good luck getting answers to any of that.

 

[ezstep]

No theories about tube watts vs. ss watts affecting the drain on the power supply?

 

[agedhorse]

Short and simple answer (from a guy who techs generators for live production shows when the so-called "generator tech" can't be found)...

The fault was not with your equipment. Period.

Whomever is in charge of the generators is an idiot or they are idiots, whatever the case may be.

For the typical festival requiring generator power to even happen, there's far more power-hungry devices and requirements than your vintage tube gear.

Stop being bummed out. Right now.

The end.

As a technical production manager with extensive generator experience myself, I agree 100% with Geri O.

Their problem was absolutely and completely unrelated to your gear. Simply not possible.

 

[Milo Spleen]

Doesn't make sense to me. It works fine, then doesn't work, then works fine. Doesn't sound like your equipment effected it to me.

 

[JimmyM]

The organization is scapegoating you and your guitarist for their generator failure so they don't get blamed and not asked to return.

 

[anderbass]

You should talk to soundman that mixed your gig, he probably caused the overload by pushing the PA's low-end/subs louder halfway through your gig.

 

[belgamrood]

You should talk to soundman that mixed your gig, he probably caused the overload by pushing the PA's low-end/subs louder halfway through your gig.

very interesting

where do you get this idea? is it possible, have you had this happen yourself once? do you have experience mixing live bands in similar settings?

reason i ask is because youre the first one to give a specific reason for the events

i am very interested what the base of your argument is

 

[Mr. Foxen]

Might be that they considered the output watt rating not the draw rating. The opposite of what people do when trying to sell stuff on ebay.

 

[beans-on-toast]

The lower the frequency, the more power it takes to reproduce those notes. If the sound guy cranked a sub or the low end or even turned up the volume level too high, the demand for power could have increased beyond the capacity of the generator.

The power requirements of the '78 SVT is 570W at full rated power. The fuse in an SVT is 10A @ 120VAC or 5A @ 240VAC (the same fuse is normally used at 220VAC). The power requirements of the '78 V4B is 280W at full rated power. The fuse in a V4B is 6A @ 120VAC or 3A @ 240VAC. So the power requirement is 850W for the two amps when producing rated power. But amps need a little more power. Note that Power = Voltage X Current. The fuses in the amps are rated for a higher current draw than the average current that the amp will draw at rated power. This allows for a higher current draw when the amp is turned on, for peaks, and a comfortable power headroom safety factor so that the generator is not overtaxed. The requirements of other appliances tied into the generator such as the PA system and lighting should have been considered. In general, PA's require more power than the amps because the output power is higher. Calculations have to be performed to ensure that the generator can meet the worst case requirements and have a reserve available.

The guy doing the power management didn't do his homework properly and was clearly looking for someone else to blame. The fact that everything was fine before and after the outage tells me that it wasn't your amps that were at fault, it was something else. As a musician, you are expected to show up at a gig with your equipment, someone else has the task of supplying power and making it work.

 

[Al Kraft]

The lower the frequency, the more power it takes to reproduce those notes. If the sound guy cranked a sub or the low end or even turned up the volume level too high, the demand for power could have increased beyond the capacity of the generator.

The power requirements of the '78 SVT is 570W at full rated power. The fuse in an SVT is 10A @ 120VAC or 5A @ 240VAC (the same fuse is normally used at 220VAC). The power requirements of the '78 V4B is 280W at full rated power. The fuse in a V4B is 6A @ 120VAC or 3A @ 240VAC. So the power requirement is 850W for the two amps when producing rated power. But amps need a little more power. Note that Power = Voltage X Current. The fuses in the amps are rated for a higher current draw than the average current that the amp will draw at rated power. This allows for a higher current draw when the amp is turned on, for peaks, and a comfortable power headroom safety factor so that the generator is not overtaxed. The requirements of other appliances tied into the generator such as the PA system and lighting should have been considered. In general, PA's require more power than the amps because the output power is higher. Calculations have to be performed to ensure that the generator can meet the worst case requirements and have a reserve available.

The guy doing the power management didn't do his homework properly and was clearly looking for someone else to blame. The fact that everything was fine before and after the outage tells me that it wasn't your amps that were at fault, it was something else. As a musician, you are expected to show up at a gig with your equipment, someone else has the task of supplying power and making it work.

+1...while there could be at least half a dozen other possible explanations, this mirrors my initial thought (which I stated rather cryptically in comparison) and is where I would still place my money for the safe bet.

 

[jlepre]

 

[RSBBass]

Even if your gear did pull more power there were only the two of you using amps. Are you seriously trying to tell me there were no four piece or bigger bands with multiple amps playing. Pure BS.