My Average Line Voltage Is 122.5 Volts

I have been measuring my line voltage everyday 3 times a day for a month and my average line voltage is 122.5 volts. So I will defiantly be building a bucking transformer circuit for my VTA ST 120 to save my tubes.

I use a Hammond 167U5 which is rated for 15 amps. Complete overkill but it only cost a few dollars more than a lower rated model. I have it wired so it drops 2.5 or 5V depending on the supplied voltage that day. I use a switch to control the different voltages. It’s actually more like 2.8 and 5.6V.

Earl wrote:I use a Hammond 167U5 which is rated for 15 amps. Complete overkill but it only cost a few dollars more than a lower rated model. I have it wired so it drops 2.5 or 5V depending on the supplied voltage that day. I use a switch to control the different voltages. It’s actually more like 2.8 and 5.6V.

I was looking at this one at 6 amps Hammond 166Q6

https://www.mouser.com/ProductDetail/Hammond-Manufacturing/166Q6?qs=zAx27f%252BWkoElcPca8RQ65g%3D%3D

Some have suggested the Hammond 166N6 at 4 amps but that transformer may run a little to hot for my liking.

https://www.mouser.com/ProductDetail/Hammond-Manufacturing/166N6?qs=dhCoiiGcT1IAXD2gHZeluA%3D%3D

I opted for Hammond 167U6 for my bucker.

LeGrace wrote:I opted for Hammond 167U6 for my bucker.

Went and looked at the specs for the Hammond 167U6 and it's perfect for this application.

It’s nice and heavy and this transformer should hold it's own with any gear you use with it.

Saved to my favorites.

Link:

https://www.digikey.com/en/products/detail/hammond-manufacturing/167U6/455329?utm_adgroup=Power%20Transformers&utm_source=google&utm_medium=cpc&utm_campaign=Shopping_Product_Transformers&utm_term=&utm_content=Power%20Transformers&gclid=CjwKCAjwx6WDBhBQEiwA_dP8rUqE13kSir0jVapKAyrGJ8RwoRm9W4wz-_3wUbZiDfIJZrQg3uqgNBoCY-8QAvD_BwE

Spec Sheet pdf

https://media.digikey.com/pdf/Data%20Sheets/Hammond%20PDFs/167_Series-Rev2018.pdf

Why not just use a $50 5Amp variac?

Rbertalotto wrote:Why not just use a $50 5Amp variac?  

I would do that if I did not have some disabilities. I have an inner ear disease that on occasion causes extreme vertigo and sometimes I become very dizzy and clumsy. I need a fixed bucking transformer so I don't accidentally bump a knob or switch like a variac that would destroy my amp if the voltage was turned up to high. Plus I already have an old variac that i'm not using anymore for this reason. Sadly it's the product of getting older and having to adjust to certain realities.

Higher line voltage here sometimes up to 126 but normally 124 plus. Pre-Variac, two red plate disasters...post-Variac, zero. I prefer the Variac maybe duct tape the knob in place.

DavidR wrote:https://www.amazon.com/dp/B000FBF08Q/?coliid=IU9VDYAMCXA9A&colid=292PN48OYLYA8&psc=1&ref_=lv_ov_lig_dp_it

I asked Bob about these and he mentioned tube amps liking a sine wave and most of the affordable conditioners don't do this so I didn't proceed even though I had one in the house.

DavidR wrote:https://www.amazon.com/dp/B000FBF08Q/?coliid=IU9VDYAMCXA9A&colid=292PN48OYLYA8&psc=1&ref_=lv_ov_lig_dp_it

I asked Bob about these and he mentioned tube amps liking a sine wave. Most of the affordable power conditioners don't do this so I didn't proceed even though I had one in the house.