[dayneger]

Hi guys,

Hugh once told me this should be possible, but it's not totally clear to me how this should be accomplished, and unfortunately my GK-1R binder is buried at an absolutely unknown location in a storage locker.    Having blown up several capacitors with my AKSA 100N as a result of not knowing that the center taps had to go to ground, I admit that I'm a little chicken to get it wrong again.

Could someone post some instructions for the rewiring?

Thanks!

Dayne

[AKSA]

Hi Dayne,

No problem - just rewire the transformer, which has TWO windings in series for 230V operation, so that the windings are in parallel, for 115V operation.

On the primary side, there are four tags on the trafos, left to right, marked beneath 0V 115V 0V 115V ES.  That last tag is an electrostatic (copper) shield around the trafo windings.

Presently, you should have a link between the center 0V and 115V tags, so that it's set up for European voltages.

Now, you simple run a link from 0V left miss a tag to 0V right (this is now 0V for US mains) and ANOTHER link from 115V left  miss a tag 115V right (this is now 115V for US mains).

ES tag is left connected to chassis just as before - no change.

The order in which you connect 0V and 115V tags to mains active or neutral is in fact unimportant.  All that is important is that you connect the two 0V tags together, and the two 115V tags together, to make to composite tags for mains connection.  This parallels the two identical primary windings, ensuring the trafo operates cool and safe.

Hope this helps,

Cheers,

Hugh

[dayneger]

Hi Hugh,

Wow, can't hope for a faster response than that!  Thanks for the description, makes a lot of sense. 

Just to be sure, for my AKSA 100N I'm using the Avel Lindberg Y23 series transformers (the ones where I didn't know that the middle secondaries went to ground, which introduced me to the smell of exploding capacitors  ).  I'm assuming I can leave the secondaries where they are again and just run the primaries in parallel?

Sounds like you had a great time in Indonesia!

Dayne

[Soundsgreat]

Hi,

I know this is a old thread,but I thought instead of posting a new thread for the same problem I can post it here and ask for a solution !!

I have a GK1 pre which my friend from US gifted (he was using it in the US,Now he's permanently shifted to India),Naturally I cannot use it here without a Voltage converter  !! But Am hesitant to use a Voltage converter !! Several reasons but main is the frequency while US is 60Hz Ours is 50Hz so even though the Converter does the voltage conversion there is no way in hell it does the same for frequency !!

So I was thinking of getting a torroid done here locally  !! I wanted to know the voltages and current rating for the same, I tried every where and even asked my friend to ask Hugh bout the same ! But so far no luck  !!

As a last resort Am posting here hoping to find an answer ! Could someone please help me here ?? Am desperately waiting for the Unit to play in my system  !!

Any help in this regard will be greatly appreciated ! Either some mods for the existing trans (Made by Victoria Magnetics,If needed can provide the serial Number too ) to make it work for 230V or the voltage and current details to get a new one made !! anything please.........

Regards.

[whubbard]

Hi,
Are you using the stock transformer that came with the GK-1?
Someone correct me if I'm wrong, but the transformer doesn't care about the frequency, so really its just 230V or 115V.

If you just need to set it up for 230V, just follow what Hugh said earier, but do the opposite.

-West

[AKSA]

Thanks West, correct!

Soundsgreat,

Australia, like India, uses 230-240V 50Hz.  The GK1 transformers are wound from grain oriented silicon steel with very low magnetic loading for superior regulation.  It will have no problem at all with 50Hz;  you don't need a toroid.

Left to right;  0V to Neutral 230Vac, connect the next 115V tag to next 0V tag, then 115V second last tag to Active 230Vac.  ES connects to the chassis and thence to the IEC mains entry module power earth.

Hope this helps, happy listening!

Cheers,

Hugh

[Soundsgreat]

Hi,

First off, thanks a lot West and Hugh for replying so fast  !!

West yes I Am using the stock transformer (at least that's what I think ) !

Someone correct me if I'm wrong, but the transformer doesn't care about the frequency, so really its just 230V or 115V.

Well I don't know,Please don't get me wrong !! But the frequency is as much important as the voltage,otherwise the transformer starts to Hum( due to frequency mismatch) which can lead to lot of other artifacts that can degrade the sound !! I mean see its as simple as this,In the US the Voltage cycles are 60 (60Hz) where as in India and other countries its 50 ! so essentially a 50 cycle one cannot be used or replaced for a product which works on 60 cycles ! I hope you get the idea !

The GK1 transformers are wound from grain oriented silicon steel with very low magnetic loading for superior regulation.  It will have no problem at all with 50Hz;  you don't need a toroid.

Hugh I think there's been some misunderstanding !! The transformer is not a E&I (from your descriptions) and does not have double primary winding that you mention !! it only has one primary winding with Ground (Green),Phase (Dark Blue),Neutral (Dark Blue) !!

So its not possible to:

Left to right;  0V to Neutral 230Vac, connect the next 115V tag to next 0V tag, then 115V second last tag to Active 230Vac.  ES connects to the chassis and thence to the IEC mains entry module power earth.

On the primary side, there are four tags on the trafos, left to right, marked beneath 0V 115V 0V 115V ES.  That last tag is an electrostatic (copper) shield around the trafo windings.

!!


I have attached the pics of the trans for the reference purpose, Either Am missing something or Am reaaaaaally stupid and not able to figure out !!

Please do let me know the next course of action !!












Regards

[whubbard]

Well, thats not the stock transformer.
I think Hugh should handle the technical details...

The 'stock' ones:


-West

[jules]

Hi SG,

odd ... a toroid and am I correct in understanding that there's only one?

You're probably best off getting a pair of the correct trafos from Hugh if that's acceptable to him. They are only small and postage shouldn't coat too much.

There should be separate outputs [and voltages] for the tube filaments, low tension and high tension.

A transformer doesn't have any inherent frequency built into it so the point West makes is valid as far as 50 - 60Hz goes.

Jules 

[AKSA]

Hi SG,

Jules and West are correct, that transformer is an off the shelf version from Victoria Magnetics, in Norcross, Georgia.

God knows how the guy got the boards, without the transformers, don't recall that one......

You really need the original transformers, two are required at $AUD50 each plus shipping.

Email me privately if you would like the ratings.

Cheers,

Hugh

[Greg Erskine]

A little bit of info on frequency with regards to transformers.

http://au.answers.yahoo.com/question/index?qid=20080802055615AAax672

[Soundsgreat]

Hi,

Thanks to Hugh and all for replying  !

West As I told I never bought these directly,it was gifted by friend to me !! so I have little or no idea bout where he bought what !! so as for me these are the stock trans  !

odd ... a toroid and am I correct in understanding that there's only one?

 Jules there two of those ! I just took pic of one  !!

There should be separate outputs [and voltages] for the tube filaments, low tension and high tension.

Yes but offcourse ! it has a 150V,15V and heater supply ! there is no probs with the trans or the specs of it ! It was being used in the US before he came to India !! so there's absolutely no reason for me to believe that the trans has a prob or otherwise !!

transformer is an off the shelf version from Victoria Magnetics, in Norcross, Georgia.

God knows how the guy got the boards, without the transformers, don't recall that one......

I have no clue or idea !!

How much would shipping cost ?? if I plan to junk this trans and order from you ??

Have sent a PM regarding the rating info !!

Greg thanks for the link !! thats one of the problems with the frequency mismatch ! but there are others including the hum and other that I mentioned earlier !!

Regards.