How to test an amp for 230v/240v operation?

[Tonegeek]

I need a way to test my amp for 230/240v systems as it is going to the UK. What is the best way to do that in the US? This is when I wish I had the right step up transformer.

Part 2) The PT I am using has a 220v and 240v tap. My voltage selector switch only has 2 positions (120 and ?) so I am thinking I should use the 240v tap as I would rather have the voltage be a bit low than too high. - Hey, we all want our amps to sag a little, right

[Leo_Gnardo]

Might you have a dryer or air conditioner outlet that delivers 240V? If so you could use that. If not, it's probable that you can find 240V inside your breaker box as that's how electricity is delivered to most homes. You would have to - very carefully - wire a temporary 240V "hot to hot" line out to your amp. If you're lucky enough to have a spare breaker on each side of the AC line, put your test wiring "downstream" from the breakers in case you have a problem then you have some protection.

Once I had to do this to repair & check out a "cycle converter" for Keith Emerson. His Hammond ran on 50 Hz 240V, and in 60 Hz countries needed the cycle converter so that the organ would play in pitch. But it ran from 240V not 120 so I had to "tie in" at my own house. Hazardous, yes, but I got through it without burning or wrecking anything. And so can you.

Please be careful. I will not be held accountable if you shock yourself or blow the place up. IOW you can ignore my directions and test your amp when you arrive in 240V land.

Too bad you're not close by. I have a couple of 2KVA autoformers that can be used either way, bump up to 240 or down to 120.

[Reeltarded]

How much is it worth to test? Few bucks and a couple days by mail.

https://www.google.com/search?q=US+to+E ... ent=safari

Oh jees.. US to Euro step up transformer. Damn I hate me some ipad.

[Reeltarded]

What Leo said there is commonplace in a recording or show environment.

Easy but not for the novice, as stated. hehe POP! (goes the 12" screwdriver)

[Tonegeek]

I do have 220 in my shop but am a little hesitant to equate that with what you would find in Europe. And maybe it does not matter but our 220 is across 2 hot legs either of which can give you 110 to the neutral and then you have a separate ground. I don't think it is the same in the UK where you have 220 from hot to neutral. Maybe my concern is unwarranted and i can just wire the 220 legs to the amp and put the ground on the ground lug. Of course all safety warnings apply.

[jelle]

I would prob get a step up transformer. 500w should be enough for most things. I have a 2kW one, FWIW. Combined with a variac in front of the transformer, you will be able to dail in the exact voltage you need. I have the ground wire bypass this system and run straight from the wall to the strip that is regulated.

Be safe!

This one looks like a smaller version of what I use and is not expensive.

http://www.amazon.com/Goldsource%C2%AE- ... d_sxp_f_pt

[cbass]

What about 50hz vs 60hz

[pdf64]

Yes, the PT is likely to be a little more efficient at 60Hz than 50Hz, so if you step up to get 240V @ 60HZ, the secondary voltages will likely be higher than when it's used in the UK 240V @ 50Hz.
Also bare in mind that the step up transformer will add supply impedance which won't be present in the UK, it will likely sag more than it will in the UK.
Pete

[Leo_Gnardo]

I do have 220 in my shop but am a little hesitant to equate that with what you would find in Europe. And maybe it does not matter but our 220 is across 2 hot legs either of which can give you 110 to the neutral and then you have a separate ground. I don't think it is the same in the UK where you have 220 from hot to neutral. Maybe my concern is unwarranted and i can just wire the 220 legs to the amp and put the ground on the ground lug. Of course all safety warnings apply.

Euro power is balanced, they don't do hot/neutral like we do so you should be good to go. And yes 50 Hz over there, now you could rig up an oscillator and a whoppin' big power amp... (I've done that too, and it ain't pretty at all.) I wouldn't worry about it, just set your amp for 220/240 & go into your shop power. Just like everywhere else you'll find the AC feed in the UK varying from 210 to 250 depending on location & other gear drawing on the line. You'll also grow to appreciate those huge UK plugs that have (usually) 13 amp fuses right in the plug. You can swap down to lower value fuses if you like.

You're right to observe that the amp's internal voltages are what matters. A good place to start is monitor the filament line for 6.3 VAC. Funny thing, practically every amp I work on here in the USA has more than 6.3 on the filament line. (Old amps that "expected" 110-117 VAC power now get 120-125 VAC in most locations.)

One thing balanced euro power plays hob with is "protection circuits" built into some AC plug strips, Radio Shack for instance. If the protect circuit sees voltage between ground and neutral, it won't send power to the strip plugs. I found out in a hurry one morning in Cannes, and had to rip the protect circuits out of all the plug strips we brought over from the USA. Got through the gig with nobody getting a shock, and no equipment failure.

FWIW there are some studios, venues, and audiophile home installations in the USA that provide balanced 120 VAC power in an effort to beat down noise that arrives via the power line.

[pdf64]

The power line here isn't balanced; there's neutral (grounded at substation), live 240V, and ground.
Comes from a 3 phase 415V local distribution.
Voltage spec is 230 V+10%−6% (253–216.2 V).
Pete

[Leo_Gnardo]

The power line here isn't balanced; there's neutral (grounded at substation), live 240V, and ground.
Comes from a 3 phase 415V local distribution.
Voltage spec is 230 V+10%−6% (253–216.2 V).
Pete

OK then please pardon my misteak. What I learned, I got from Showpower. Their AC to performance stages was balanced, including the 120V lines.

In any case Tonegeek will be able to audition his amp powered by 220-240 VAC. Hopefully he will be able to skip the "tie in" process.

[Aurora]

FWIW - 230V balanced is termed an IT power network...... I think it is only us here in Norway, that uses that - the rest of Europe is hot/Neutral, called a TN net.....

[amplifiednation]

I would prob get a step up transformer. 500w should be enough for most things. I have a 2kW one, FWIW. Combined with a variac in front of the transformer, you will be able to dail in the exact voltage you need. I have the ground wire bypass this system and run straight from the wall to the strip that is regulated.

Be safe!

This one looks like a smaller version of what I use and is not expensive.

http://www.amazon.com/Goldsource%C2%AE- ... d_sxp_f_pt

That's pretty sweet. So in order to get the amp powered up do you use a Euro IEC cord or do you purchase a plug adapter? Like this one?

http://www.amazon.com/Power-Bright-3-Pr ... +converter