Bottlehead Forum

Bottlehead Kits => Legacy Kit Products => Foreplay III => Topic started by: John Roman on September 27, 2011, 04:32:29 AM

Title: Just to confirm heater resistor
Post by: John Roman on September 27, 2011, 04:32:29 AM

I have an Extended Foreplay III and am in the process of converting the output tubes to 6sn7's. I want to keep the 12au7 as the shunt regulator. The heater supply resistor is currently .62/5w .  That resistor should be changed to .22/5w? Correct?

Title: Re: Just to confirm heater resistor
Post by: Paul Joppa on September 27, 2011, 06:21:53 AM

My notes say 0.15 ohms for 1.5 amps (0.6+0.6+0.3) assuming your power line is close to 120 volts.

Title: Re: Just to confirm heater resistor
Post by: John Roman on September 27, 2011, 06:41:07 AM

Thanks Paul!