Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: davidwpack on February 26, 2019, 10:57:48 am

Title: Branch circuit?
Post by: davidwpack on February 26, 2019, 10:57:48 am

I think I know the answer but is there any problems branching the filament circuit? In other words running the transformer's filament wires to a terminal then running 1 set of wires to the tube filaments and another set to the lamp? Not sure I want to try it yet but I think I may be able to do a neater run of wire this way.  Danke ye!

Title: Re: Branch circuit?
Post by: sluckey on February 26, 2019, 11:10:26 am

No problem at all. I've had to do this on several builds, mostly because of using salvaged PTs with too short leads. Looks better than splicing wires IMO.

Title: Re: Branch circuit?
Post by: vampwizzard on February 26, 2019, 11:15:16 am

agreed. The main reason its done paralleled is to save on the amount of wire. not that heaters fail on you often but you'd be easier to diagnose any issues more easily as well.

Title: Re: Branch circuit?
Post by: davidwpack on February 26, 2019, 11:29:00 am

Thanks guys!

Title: Re: Branch circuit?
Post by: jjasilli on February 26, 2019, 06:51:40 pm

Yes, and note that a typical filament string carries a lot of current, requiring heavier gauge wire.  With "branches", you may have the option to use thinner gauge wire, where less current is flowing.

Title: Re: Branch circuit?
Post by: davidwpack on February 27, 2019, 08:43:20 am

Yeah, I ran 22g to the lamp and 20 for the filaments.