Newb layout question

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Bane
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Newb layout question

Post by Bane »

I'm building my first amp. I'm building a 5e3 to get my feet wet before I dive into an 18 watt. I'm testing now and have run into a problem. I'm not getting proper voltage to my preamp tubes. I'm backtracking to to try and figure out where I went wrong and the first thing I'm seeing is I haven't done anything on the pins marked "Fil". I have no idea what "Fil" is. I've searched for the term and can't find anything. Can someone educate me please. Thanks in advance!
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JMPGuitars
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Re: Newb layout question

Post by JMPGuitars »

Welcome to the site!

Fil is short for Filament, meaning the heater wires. Tubes don't work without them.

Thanks,
Josh
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Bieworm
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Re: Newb layout question

Post by Bieworm »

Bane wrote:
Sun 05/16/21 7:24 am
I'm building my first amp. I'm building a 5e3 to get my feet wet before I dive into an 18 watt. I'm testing now and have run into a problem. I'm not getting proper voltage to my preamp tubes. I'm backtracking to to try and figure out where I went wrong and the first thing I'm seeing is I haven't done anything on the pins marked "Fil". I have no idea what "Fil" is. I've searched for the term and can't find anything. Can someone educate me please. Thanks in advance!
Fil = filaments or heater pins. On 12A.. preamp tubes it's pins 4+5 and 9 if wired parallel. And on EL84 output tubes it's pins 4 and 5.
Post detailed pics of your build + voltages measured per tube and voltages of the B+ line
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Bane
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Re: Newb layout question

Post by Bane »

Wow. That explains it!! Sheesh. That was a pretty big miss huh? Going back over my layout, looks like I go from the lamp to each tube. No idea how I missed that, and I feel like an idiot for it, but thank you guys!
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AussieTim
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Re: Newb layout question

Post by AussieTim »

There are no stupid questions, just stupid answers, we all have brain-fades sometimes and often those brain-fades lead to a eureka moment, and the lesson is never forgotten thus becoming a better learnt lesson than if thought we understood it in the first place.
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Bane
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Re: Newb layout question

Post by Bane »

Heaters are in, now on to the next problem. Thanks again guys. That was a real "doh" moment:)
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