Bottlehead Forum

Bottlehead Kits => BeePre => Topic started by: grosen on January 27, 2021, 01:33:23 PM

Title: BeePre2 transformer wiring question
Post by: grosen on January 27, 2021, 01:33:23 PM

Hi all,

I jumped on the BeePre2 early and I'm looking forward to the build, but I had a question.  I'm one of those people who had a problem voltage sag-induced hum with my old BeePre.  My wall voltage is 117 - 120V most of the year, but routinely drops to 110V during the summer when the air conditioners are raging.   I use a variac to compensate, and that works.  But I was hoping to avoid that with the BeePre2, so here's the question: should I wire the transformer as if my wall voltage is less than 115V (p. 26 of the new manual), or as if it's between 115V and 130V (p. 27)?    It won't be optimal either way, but I'm wondering whether it's better to be over than under. 

Thanks,

Gideon 

Title: Re: BeePre2 transformer wiring question
Post by: Paul Birkeland on January 27, 2021, 01:47:54 PM

I would suggest wiring it for 120V for now.  If the summer hits and you get regulator dropout noise (which is already less likely from the new design), you could get a simple SPDT toggle switch to send the black wire from N to either set of terminals, so you can just flip the switch on the top plate if necessary. 

I definitely wouldn't build this in unless you absolutely need it though. 

Title: Re: BeePre2 transformer wiring question
Post by: grosen on January 28, 2021, 12:29:57 PM

Thanks, Paul.   I'll wire it for 120V and see what happens.