Problems with Xduoo ta-03s tube amp

[asgerllll]

So I recently bought this tube amp off of drop.com, problem is the amp needs 110V and the outlets where I live are 230V, I did not know this. Amp came with an US plug but I had an EU plug that I plugged in and blew the fuse. I then got at step down converter 230V to 110V, but I could not find a fitting 2A fuse anywhere close to me and a worker at the hardware store told me for an amp a 3A fuse would be fine. I replaced the fuse and plugged the unit into the power converter and then turned on. Thought I had fixed the issue but amp started smelling burnt and even let out a tiny bit of smoke before I could turn it off, it did not turn off by itself.

I am wondering if the amp is toast now or if there is any chance that it could still work, I have not tried plugging it in again because I have no idea what power I am supposed to use for it. I thought the 230 to 110V converter was what I needed, but obviously it started frying my amp... Anyone here with experience in using step down converters or with fried amps who has any idea what went wrong?

[The Dude]

So I recently bought this tube amp off of drop.com, problem is the amp needs 110V and the outlets where I live are 230V, I did not know this. Amp came with an US plug but I had an EU plug that I plugged in and blew the fuse......

You should have stopped right there (or before!). You applied 230V to an amp configured for 110V and obviously shorted something if it took out the fuse. Putting in another fuse without fixing the problem wouldn't solve anything, especially using a fuse that's rated higher than what the amp calls for. It's time to take the amp to a qualified tech.

[asgerllll]

You should have stopped right there (or before!). You applied 230V to an amp configured for 110V and obviously shorted something if it took out the fuse. Putting in another fuse without fixing the problem wouldn't solve anything, especially using a fuse that's rated higher than what the amp calls for. It's time to take the amp to a qualified tech.

Yeah I know I screwed up initially, but with the step down power converter I was applying only 110V and the amp still fried. I assumed I had the correct power and I could plug in the right fuse later when I could get one.
Power converter I used is a "Nedis 230 V AC to 110 V AC Converter" with 100 VA output power.

[The Dude]

The amp was already fried when you plugged 230V into it, which is why the fuse blew. It wouldn't matter what you did after that.

[asgerllll]

The amp was already fried when you plugged 230V into it, which is why the fuse blew. It wouldn't matter what you did after that.

Ahhh that makes sense, I thought the fuse saved it from frying because I could not smell anything burnt and the amp "on" light never turned on. I will look for a professional amp tech, thanks for the advice

[The Dude]

I suspect something shorted and the fuse blew on first power up because of overvoltage. The 3A overrated fuse is probably what let the smoke out the second time. If fused correctly, the fuse may have blown again before more damage was done.

[Helmholtz]

Agree with the Dude.

Twice the voltage will cause the power transformer to saturate making it look like short.
Also the filter caps and other components in the amp might have seen 800+V causing them to blow.

Apart from that a 100W electronic converter might not be suitable here.
What is the power output of your amp? Is there a plate that specifies mains input power and fuse rating? If the amp needs a 2A fuse, it might consume up to 200W.

Generally an electronic switching converter might not be compatible with a non-linear load like an amplifier drawing pulse currents.

Have your amp repaired and get a real step-down transformer of sufficient VA rating.

[The Dude]

Worse yet: This unit is pretty modern technology with USB in and digital audio decoding, so I strongly suspect the power supply is SMPS. It's not likely going to be a cheap fix. That is, of course, just a guess without seeing a schematic.

[Mick Bailey]

The spec says it's a linear PSU, so maybe some hope there. My own experience of US voltage amps operated on 230//240v is the mains transformer will at least have shorted turns (needing replacement) and likely there's a fair bit of damage to components on the secondary side.

[asgerllll]

The 3A overrated fuse is probably what let the smoke out the second time. If fused correctly, the fuse may have blown again before more damage was done.

Was a glass fuse so might have contained the smoke. The burnt smell was very metallic, which I am guessing is not a good sign

[Augustine]

Same thing happened to me, plugged in 240V without realizing that it was rated 110V. Found out that a resistor (R37) was fried. Unfortunately I couldn’t find the circuit diagram and cannot figure out the resistor value. Would appreciate if anyone can let me know it’s value or post a photo of the circuit board so I can read the value off the color band on it.