Rewinding 165va to 127

[elogicca]

Is there any issues with winding a 165va transformer down to 127? it's an off the shelf hammond?

[Al_The_Man]

Do you mean 165VA or 165VAC?
If VAC, Not usually, you can either try and determine the turns/volt ratio ahead, by winding on 5~10 turns of enameled wire, gauge does not matter,
And measure the resultant AC.
Or take a guess and figure 2t/v and give it a try, trouble is it is a pain if you take off too much.
Al.

[elogicca]

12v 20 amp to 9v 15 amp

[Al_The_Man]

the VA rating will remain the same, whatever you do to the winding, the problem comes when you want to decrease the voltage and increase the current for a given VA, in that case the winding may not be rated for that current, but if you are dropping the voltage and running at a lower current, or increase the voltage and decrease the current, then you are still within the VA rating of the transformer. (9x15 is less than 12x20).
Al.