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Author Topic: Fender Sunn Model T Power Supply rewire for UK  (Read 129 times)

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Fender Sunn Model T Power Supply rewire for UK
« on: March 23, 2019, 10:33:41 am »


I?m after some advice and knowledge from any of the amp technicians and amp builders on here! I was kindly pointed in this direction by @watson after asking the same question on a Facebook group.

I have just received a Fender Model T from the states (I live in UK) it?s currently wired for 120v/60hz US power supply. I wanted to ask about converting to UK 230v/50hz.

From the Fender schematics supplied on their site (see pic). It suggests this is relatively straight forward with rewiring the links to the power transformer and swapping fuses to T2A.

My question is apart from rewiring the input to transformer set up and replacing T4A for T2A fuses. Are there any other things to consider? Watson suggested the hz change causing the amp to run ?hot? but from the schematic chart saying 50/60hz under every voltage alternative I?m assuming the hz change from country to country was considered when building the amp.

Are there any known effects this power supply change will have on the amp regarding sound or anything else?

Obviously this is something I want to do properly without any issues or effects on the amps performance. From the schematic it seems that it was considered from day one that the amp could be set up on different voltage systems but always worth checking if anyone has done this and has any input on carrying out this job.

Also as I want to use the amp immediately and I?m not going to tackle to task myself are there any things to consider when buying an external step down power supply transformer? There are so many out there it?s hard to know what tech specs are important to consider.

Many thanks for any advice in advance!


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Re: Fender Sunn Model T Power Supply rewire for UK
« Reply #1 on: March 24, 2019, 10:00:18 am »

I'm not really familiar with the Fender Model T, so take anything I say with the appropriate amount of caution.

I agree with you that the 50/60 Hz designation implies that line frequency should not be an issue. I wouldn't worry about that.

Have you measured your line voltage? In your place, I would, just to make sure as to which would be preferable, 230 or 240. Other than that, as you say, it does look to be pretty straightforward.

When I lived in Italy, some thirty years ago, we used transformers to run all of our gear. The only thing that had any issue was my TEAC 4-track. The difference between 50 and 60 Hz made it run slow, so all of the recordings I made there are now sped up. Other than that, we had no problems at all, certainly none with any of our amps. I wouldn't hesitate to use it with a step-down transformer.