ST70 Line Voltage?

Well I was just looking for advice regarding what to use to drop the line voltage into the ST-70. my intention is for equipment protection, not concerned about voltage regulation in a strict sense.

so now a little confused. seems like either a Variac or a step down transformer (bucking) would work; just looking for a simple method. the size of a transformer, from what I have seen, would be more desirable than a larger Variac. I have space issues. I am open to either.

I put together a bucker with a toggle switch to select -3 VAC or -6 VAC (about for each). My voltage some days is as high as 128VAC, never lower than 122 VAC.
Mouser #:546-167U6 transformer

sorry for the insanely large photos, don't know how to reduce their sizes

I'd just go with a bucking trans and forgot about it - I use my Variac on my test bench and it is big. Also if you bump or accidently move the knob on the variac is a concern. Just my 2 cents

[quote="cci1492"]I put together a bucker with a toggle switch to select -3 VAC or -6 VAC (about for each). My voltage some days is as high as 128VAC, never lower than 122 VAC.
Mouser #:546-167U6 transformer

sorry for the insanely large photos, don't know how to reduce their sizes



Nice work!

A few volts can make a big change of voltage internally. Here's a comparison of 115.1V vs 120.6V and what happens internally for my M-125 amps. The biggest change is 43V from only a 3.5V change of line voltage.

tubey1 wrote:I'd just go with a bucking trans and forgot about it - I use my Variac on my test bench and it is big. Also if you bump or accidently move the knob on the variac is a concern. Just my 2 cents

That's been my thought all along. Thanks for the input. Now to find one.