Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Tone Junkie on March 07, 2012, 01:49:13 pm

Title: understanding chokes
Post by: Tone Junkie on March 07, 2012, 01:49:13 pm

Ok Im building a 100 watt amp I dont build many of those I would like to use a hammond 159q choke i like the way they sound in a marshall style build but the specs are 7H 150 MA. 500vdc is a 150 MA to low because the power transformer is 290 MA.
Thanks Bill

Title: Re: understanding chokes
Post by: sluckey on March 07, 2012, 02:00:01 pm

Most typical 100W amps don't run the output tube plate current through the choke so you will be fine unless you're building something unusual.

Title: Re: understanding chokes
Post by: Tone Junkie on March 08, 2012, 01:32:00 am

Thanks Steve just standard marshal type power amp.

Title: Re: understanding chokes
Post by: HotBluePlates on March 08, 2012, 05:24:59 pm

I've got a project going right now which has 2 chokes. One handles the whole-amp current, and is rated for 200mA (for 2 6L6-style output tubes, 3 preamp tubes).

The other choke handles only preamp current. It is vastly overrated at 75mA (again, handling 3 small tubes), but much cheaper than a sensibly-rated part custom-made. It might even be vastly overrated for your amp, in the typical Marshall position feeding the screens.

Title: Re: understanding chokes
Post by: Tone Junkie on March 09, 2012, 01:41:30 am

Cool HotBluePlates tell us how its coming along as you go.
Bill