Using a US Mesa in the UK - potential issues?

[guitarbloke]

(apologies in advance for the newb questions which are about to follow!)

So my Roadster is due to arrive on Monday, but I have loads of questions which I hope you guys can help me out with

I'm in the UK, but the amp is a US model Roadster head (2007) and so is coming with a step-down transformer which the previous owner says he's been using without issue for a couple of years.

Now I don't know much about these things, but are they safe, or can they cause amp damage? Do they cause any additional background hum? Are there some models of step down transformer to stay away from? Should I make sure that the one I receive is a particular type/power rating?

Can the amp be modded easily (i.e cheaply) to take UK power? Or would a new transformer be in order? (I 've heard that new transformers can be pricey)

With regard to the fuses - according to the pics I've seen, the rear of the amp says "4a 120v SloBlo" by the fuse. However in the UK I can only find 4a 250v SloBlo/Slow Blow. Would using this 4a 250v fuse cause a problem? I vaguely touched on this in a previous post recently but I didn't quite ask the right questions.

Finally, just out of curiosity, have there been any further revisions of the Roadster since 2007? I can't find anything to indicate this online, but thought I'd ask

I think that's all my questions - for now!

Thanks for your help!

 

[r_cod_81]

I got a US rectifier preamp yesterday and a 240-to-120 V converter from Maplin for 40 quid. Just make sure that it can hande the power requirements of the US amp. It is absolutely silent when all running though.

Swapping the power transformer is possible but a new transformer will probably be more expensive than a voltage converter.

Re: fuses, It is the current rating that is important. As long as you have a 4 amp fuse you should be fine. If you're really concerned you should be able to find 120V fuses from somewhere like Farnell or RS is Maplin don't have more 'unusual' rated components.

 

[domct203]

If you plan to play the amp at band/gig volumes you should use a 1000W rated transformer.

Going by the fuse rating, the amp could theoreticly draw 480W before the fuse would fail (120V X 4A = 480W), and being a Slo-Blo design, is capable of allowing much higher surges from the amp.

Don't skimp on the power supply to the amp, it is that important! Also consider a good quality power conditioner to filter EMI/RFI and provide surge protection. I would get a 120V model that will protect from over-voltage as well, and place it between the stepdown transformer and amp.

Dom

 

[guitarbloke]

Thanks guys. Wow, 1000w sounds like a lot - would 500w definitely not be enough then?

Is there anyway of calculating how much power is needed from the step down transformer?

 

[elvis]

The biggest danger is blowing the minds of the Brits with some hard-core American amp technology

 

[BaklavaMetal]

i had the same problem, 8 months ago i bought a US dual recto head. i bought a 300w (couldnt find a 500/600w here in croatia, only 1200 and that was too expensive)stepdown transformer, and i haven't had any problems, except one blown fuse a month ago. replaced it with 3,5A fuse (they didn't have 4A) and it's been working without a glitch ever since. i've been checking the transformer for overheating, but it barely even warms up after 3 hours of playing.

by the way, i'm not talking about playing at bedroom levels

 

[94Tremoverb]

500W is fine even at band volume. Fully cranked the amp draws less than 400W, and you're unlikely to actually drive it that hard anyway - that would be into full power stage distortion and insanely loud. If you keep the clean channel clean you're unlikely to go much above half that. The fuse is rated at 4A/120V because that is *above* the maximum current draw of the amp, except under fault conditions.

There is absolutely no issue with using a 250V fuse in place of a 120V one, that's simply the maximum voltage that the fuse is rated as being safe for. Higher is better.

 

[guitarbloke]

Thanks to all of you, that info is really reassuring!

I'm now really looking forward to trying her out over the weekend!

 

[BoogieJem]

I've been using a US spec MKIV in the UK with a Maplins step down transformer (500W I think) for 10 years wiith no problems.