Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: chocopower on February 19, 2018, 04:08:06 pm

Title: First power on question.
Post by: chocopower on February 19, 2018, 04:08:06 pm

New rebuild amp.
I have no variac, but i use a step down transformer (220v to 120v) so in the first power on, amp get lower voltage. I'm from Spain. 220vac here.
I use too, a current limiter bulb.
My question is:


220vac---step down transformer----bulb---amp


Or


220vac---bulb---step down transformer---amp




I only have 220vac bulbs, so i dont know how they could work after the stepdown transformer.


Thanks in advance.

Title: Re: First power on question.
Post by: sluckey on February 19, 2018, 04:21:30 pm

I suggest 220v to current limiter bulb to amp. Forget about the stepdown transformer.

Title: Re: First power on question.
Post by: chocopower on February 19, 2018, 04:39:22 pm

Thats the way i use to do... but this time im a bit worried about P.T. primary wiring. Is a old amp and wires are  bit confusing im primary side.
I'm 99.99% sure about my work, but in the catastrofic situattion i picked a 120v primary widding, i want to use the step down transformer.....


I realize that i'm being a bit paranoic, but ....

Title: Re: First power on question.
Post by: kagliostro on February 19, 2018, 05:51:40 pm

..... 220V line > Lamp Limiter > 220V/110V Step Down Transformer > Amp  (may be ???)


Franco