B-52 AT100

[adam8419]

I've got a US version of the B-52 AT100. I live in the UK so the voltage is different. I was going to use a voltage transformer but could I just change the AC fuse and not use an external transformer? I had a look at the schematic and I couldn't see anything else that would need changing but I am new to tube amps so could be missing something important.

[olddawg]

I an assuming the amp does not have a voltage selector switch on the back. Look and see if the power transformer has 240 volt taps on the primary. If it does you can rewire your 240v mains to them. If it only has 120v taps you will need an external step down transformer.

[Enzo]

The schematic shows a single primary winding, and I have one open right in front of me at the moment. There are not duakl primaries, which woulod be necessary for switchable mains voltage.

YOu will need to get either a step down transformer for it, or get a B-52 240v power transformer and install it in the amp.

[adam8419]

ok, i'll go with a step down transformer for the time being and look into a power transformer as a more permanent solution. Thanks for your help

[clydey]

today on ebay uk i have just bought a 240v - 110v stand alone transformer
i think the seller has about 9 left
£14.95 collect in person or an xtra £12 carriage
they are 2.25 kva dual output samsons
dial in transformer samsons for a look
cheers

[Steve Conner]

Good call clydey...

RS also used to sell autotransformers that could maybe be mounted inside the case of your amp, if there was any room. I have a 100VA one kicking around somewhere, but you'd probably need a 200.

An autotransformer is lighter than a regular one of the same rating, but it doesn't isolate from the mains. That's usually not a problem.

Block | Transformers | Transformers | Auto Transformers | Portable Step-Down Auto Transformers SAT series |SAT200

[clydey]

one of the techs had replied to a post of mine regarding testing equipment and recommended a b&k precision 520b in/out of circuit transistor tester.
i bought one last week brand new old stock for £136 including shipping from usa. this one needs the 110 volts supply hence the purchase. just waiting on the tester
ps i do have the diode test on my meter
cheers

[adam8419]

The amp draws 450w so i'd need the 500VA version of the RS transformer posted wouldn't I? The ebay one is cheaper but the RS is more compact which would be handy for gigging.