How do I convert my 110V B+K amp to run on 220V power?

[mixersoft]

I've got a B+K AV5000 power amp from the US, runs on 110 60Hz AC power. Now I have moved to china (220V 50Hz), and the thing keeps blowing the circuit breaker when I plug it into the step down transformer.

Can someone tell me if it is easy to convert to 220 power? Or should I just try to sell it an buy something locally?

TIA.

[jaycee]

Unless the power transformer inside the unit can be rewired for 230V operation, then no.

Easiest way to tell, open the unit and find out if there are 2 primary wires or 4. If there are 4 and they are wired in parallel at the moment, then they can be wired in series for 230V use. If there are only 2, then the transformer is only designed for 120V input.

I'm assuming here that you are familiar enough with electronics to be able to do this. If not, then sell it and buy a new amp.

[SoNic_real_one]

Most likely you won't have 2 separate 120V windings connected in parallel (that you could connect in series to make 240V). That wold be to easy (just take care of the proper phasing)
You have 2 options:
1. Open the amp, remove the transformer, rewire the primary coil (double the number of turns with a smaller wire). Reinstall the transformer.
2. Use a down-converter autotransformer or transformer with the size appropriate for the maximum power written on your amplifier.
You cannot use "converters" that have solid state devices inside, you need transformers (heavy, massive iron core and copper windings thingies).

[cliffforrest]

Originally posted by SoNic_real_one
Most likely you won't have 2 separate 120V windings connected in parallel (that you could connect in series to make 240V). That wold be to easy (just take care of the proper phasing)
You have 2 options:
1. Open the amp, remove the transformer, rewire the primary coil (double the number of turns with a smaller wire). Reinstall the transformer.
2. Use a down-converter autotransformer or transformer with the size appropriate for the maximum power written on your amplifier.
You cannot use "converters" that have solid state devices inside, you need transformers (heavy, massive iron core and copper windings thingies).

That really is not very smart advice!

1) suggesting that unskilled people rewind a power transformer is daft and dangerous!

2) OP has already stated that it blows te breaker on his autotransformer.


The manual can be found here

easily found in Google and it includes info that the line voltage is switchable. So open the lid and look for jumpers, switches.

[wboyd]

From page 11 in the above posted pdf file:

Line voltage 120/220/240 VAC switchable

There is probably a simple switch inside....worst case you will have to desolder and resolder a couple of connections on the AC side of the transformer.

If you don's see a switch...look on the side of the transformer for a wiring diagram. If there is no diagram, I bet the transformer has some sort of ID/reference number on it.

Don't make it a complicated thing....if all else fails...call the manufacturer.

[carlmart]

Originally posted by mixersoft
I've got a B+K AV5000 power amp from the US, runs on 110 60Hz AC power. Now I have moved to china (220V 50Hz), and the thing keeps blowing the circuit breaker when I plug it into the step down transformer.

Can someone tell me if it is easy to convert to 220 power? Or should I just try to sell it an buy something locally?

If the amplifier does not have a switch on the back indicating 110/220v it's quite unlikely it will be bi-voltage. All amplifiers released in the US are only 110v, probably because a transformer for two voltages would be difficult to design and not compromise the amp output.

Look on the back if there's a plate with the amp consumption, in amps or watts. The step down transformer should be equal or exceed that number.

[mixersoft]

Hi all,

Thanks for your input. Here's what I know

• I have the AV5000 series 1, the sticker on the back says 120vac 60Hz
• I called the mfg, and tech support said any "service center" could switch it to 220v, but they have are no service centers outside of the US. He was reluctant to say any more to an end user like me
• I opened up the amp and the primary coil of the transformer has 5 wires connected as follows:

red ----- [+] --- + ----red -----) ( -------
+ ----white --) (
) (
120V open ---- gray -----) (
) (
+ --- black ----) (
black ---- [-] --- + --- brown --) (------


From the notes above, I suspect there are 2 primary coils wired in parallel, with the gray wire going currently connected to nothing. I am going to try to borrow a voltage meter to confirm this.

But can someone help me confirm that to make the switch to 220V, I just wire the 2 coils in series? Also, I'm not sure how to deal with the phase issue.

Assuming Red/Black is one coil and White/Brown is another coil, do I just connect Black+Brown or something like that?

Many thanks for your help

[AndrewT]

the phase issue and any other mistakes in re-wiring can be addressed safely by using a light bulb tester between the mains socket outlet and the modified equipment mains plug top.

If the bulb lights, the equipment has been wired wrongly.
If the bulb flashes briefly and goes off then check you have 220Vac at the input of the equipment and that you have the correct voltage at the secondaries.

Once you know that all is OK, plug the modified equipment direct to the mains socket outlet.

[djk]

Do you even know if the transformer is rated for 50hz?

The AV5000II is stated at being 120V/240V ready, and it is quite a bit heavier than the AV5000 that is marked 120V.

The original may not be 50hz rated.

[mixersoft]

I don't know the answer to that. Is 60 vs. 50Hz a big issue for a power amp? I thought that was only and issue for electric motors. I will wait for an answer on this one.

BTW, my line "diagram" didn't survive the posting, so I am uploading a photo showing the 5 leads from the transformer primary connect to the AC mains.

Is it reasonable to assume that when set for 110V, those are dual primary windings, connected in parallel and in phase?