switching Class D amp to 110v, do I need a new fuse?

[BassPimp66]

Class D gurus wanted.

I have a markbass MB1000 class D power amp running at 220v. I want to take it to the US and run it in 110v.

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OK, I found the jumper wires and tutorials from other threads.

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But, I don't know what value I need to change the fuse. It's not given on the user manual.
The 220v fuse is a 6.3 A (slow). Any idea what I should change it to for the US?

Thanks.

Edited March 16, 2013 by BassPimp66

[icastle]

To make things difficult (sorry ) some amps don't actually require a fuse change and Markbass are very 'picky' about releasing information about doing these conversions yourself.

Any warranty you may have on the amp will go out of the window as soon as you touch the chassis with a screwdriver.

Most amps that do require a fuse change to allow 110V operation seem to shift from a T6.3A to a T10A.

My gut reaction would be to play safe - try the amp with the existing T6.3A and, if it blows, change it for a T10A.

[BassPimp66]

[quote name='icastle' timestamp='1363479950' post='2013310']
To make things difficult (sorry ) some amps don't actually require a fuse change and Markbass are very 'picky' about releasing information about doing these conversions yourself.

Any warranty you may have on the amp will go out of the window as soon as you touch the chassis with a screwdriver.

Most amps that do require a fuse change to allow 110V operation seem to shift from a T6.3A to a T10A.

My gut reaction would be to play safe - try the amp with the existing T6.3A and, if it blows, change it for a T10A.
[/quote]

Cheers! I will try that.

[flyfisher]

Regardless of the operating voltage, the amp will require roughly the same amount of power to operate. Thus, broadly, if the operating voltage is halved, the current will be doubled.

If the fuse is rated at 6.3A for 220v then this should be adequate when operating at full volume. If the voltage is change to 110v and the amp is only used at 'moderate' volumes then the 6.3A fuse will likely be fine. But if the amp is used at full whack, a 6.3A fuse may eventually blow and this might happen in the middle of a gig.

Ideally, when converting to 110v operation, the fuse should be changed to the rating recommended by the manufacturer. This should be fairly easy to find out, I would expect. It will do not harm to the amp to leave the 6.3A fuse in place, but It does leave the risk of a mid-gig failure.

[Phil Starr]

6.3A at 110V is marginally under 700W. Even class D isn't 100% efficient so your fuse could blow if you run at high power with any distortion effects or a lot of compression. However if you run 'normally' ie less than flat out with a clean input from the bass and without overdone fx then even if you run into limiting from time to time your average power drain is likely to be less than 100W so a slow blow fuse is unlikely to blow. They are heat devices and they will cool in the gaps between notes. They also deteriorate over time so a new fuse is less likely to blow than an old one.

If the fuse is easily accessible I think I wouldn't worry about having a 700W fuse in my amp, I'd just carry a box of spares and make sure I replaced the fuse once a year. It's going to be pretty loud after all if your average power is 500W! If it became a problem I'd go for a 10A fuse. Again I wouldn't worry, the fuse only really does anything if there is a real problem with a short circuit or catastrophic breakdown inside the amp, It's there to stop things catching fire really, if your amp is drawing a continuous current of over 6A then there really is something wrong and your amp won't be working anyway.

If I was moving to the States permanently I'd check with Markbass and have it converted though.