[Oedipus Rex]

Hi,

I got myself the Japanese version of the Stax srm-007tA and was wondering what kind of voltage converter should I choose and how much power would it need (the amp says 55W but that seems kinda low). Also, does anyone know a good place to buy one?

Hopely soon I can get a subjective idea whether there are differences between electrostatic amps

 

[spritzer]

Just change the voltage internally. This has been documented here countless times since all Stax amps use the same primary setup.

 

[Oedipus Rex]

Quote:

Originally Posted by spritzer /img/forum/go_quote.gif Just change the voltage internally. This has been documented here countless times since all Stax amps use the same primary setup.

Hmm, after over an hour of searching, the only information about changing the voltage internally was that stax has "recently" made it difficult by "cutting wires".

Maybe you could point me to one of these countless documents please? It would be really cool if I didn't have to buy a transformer.

kind regards

 

[spritzer]

These are the jumpers that need to be soldered in:

1,3,6 is definitely 100 volts

2,4,6 is definitely 120 volts

3,5 is definitely 220 volts

2,5 is definitely 240 volts

If there are any missing wires from the transformer then you need to add those. Use the proper wire size and voltage rating. Please do not try this though if you don't know what you are doing...

 

[Oedipus Rex]

Thanks for the info!

Quote:

Originally Posted by spritzer /img/forum/go_quote.gif Please do not try this though if you don't know what you are doing...

I have absolutely no Idea what I'm doing

So would this kind of gadget work:
JA0300 : 300VA Japanese voltage converter230V to 100V (3 pin or 2 pin Japanese plug outlet)

 

[spritzer]

That would work.

 

[Oedipus Rex]

Quote:

Originally Posted by spritzer /img/forum/go_quote.gif These are the jumpers that need to be soldered in: 1,3,6 is definitely 100 volts 2,4,6 is definitely 120 volts 3,5 is definitely 220 volts 2,5 is definitely 240 volts If there are any missing wires from the transformer then you need to add those. Use the proper wire size and voltage rating. Please do not try this though if you don't know what you are doing...

Ok my amp finally arrived

How can I tell if there are any wires missing? Do I have to take the whole thing apart. I took a few pictures from the inside, is it possible to determine from these whether the wires are cut or not?

Thanks!

 

[Bullseye]

You can also buy a step down transformer if you don't want to solder.

 

[Oedipus Rex]

Quote:

Originally Posted by Bullseye /img/forum/go_quote.gif You can also buy a step down transformer if you don't want to solder.

It seems that step-down transformers from 230V to 100V very rare, I asked around and you cannot buy that kind of step down transformer anywhere in Finland. I was only able to find one source in the net selling such, and the cost was around 100 Euros shipped.

 

[spritzer]

You can easily find stepdown transformers on ebay for 100v and they are quite cheap. Most come from Asia though so shipping, VAT etc...

Now for the amp, the wires are all there and you need to make the adjustments on that little PCB fixed to the side of the chassis. There are a number of versions of these PCB's so I have to see a picture of it to know what the next step is. You will have to solder and desolder a bit though.

 

[Oedipus Rex]

Quote:

Originally Posted by spritzer /img/forum/go_quote.gif You can easily find stepdown transformers on ebay for 100v and they are quite cheap. Most come from Asia though so shipping, VAT etc... Now for the amp, the wires are all there and you need to make the adjustments on that little PCB fixed to the side of the chassis. There are a number of versions of these PCB's so I have to see a picture of it to know what the next step is. You will have to solder and desolder a bit though.

Ok, I found some on Ebay, thanks! (though most transformers that are addvertised as 100v are actually 110v when you take closer look?)

Btw, does it matter how powerful transformer I take as long as it has more watts than what is listed in the amp (55 Watts) .. so would there be any difference whether the transformer is 80W or 300W

best regards

 

[spritzer]

I would use at least double the rated current draw for some extra headroom so a 100W unit would be enough. You can use smaller but one never knows how accurate those ratings are.