Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: cfortner on August 02, 2023, 07:41:12 am

Title: Two heater circuits - grounding both?
Post by: cfortner on August 02, 2023, 07:41:12 am

Hi,

for my new amp with six KT120 I bought a transformer with two independent heater windings, 6,3V 12A and 12,6V 2A.

Now I‘m wondering if I have to ground both windings with two 100 Ohm resistors or only one of them.

Any suggestions?

Title: Re: Two heater circuits - grounding both?
Post by: sluckey on August 02, 2023, 07:43:54 am

Each winding needs a ground reference. This means four resistors.

Title: Re: Two heater circuits - grounding both?
Post by: cfortner on August 02, 2023, 09:12:13 am

Thanks a lot!

I found a hifi amp with 6,3V and two 25,2V (two tubes in serial), where was written NOT to ground the 25,2V windings, only 6,3V.