Amp Nomenclature for Newbies

screefer

Tele-Afflicted
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Feb 28, 2016
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kildonan
We're all newbies at some point, eh?

I'm about to start my second build and despite extended reading, I still struggle with concepts and terminology.
With no previous exposure to electronics, I find it amazing that, in amps, there exists AC and DC current in the same wire, at the same time, and going in different directions.
Current flow, apparently, is opposite to electron flow. We send things to ground but that is where the electrons come from!!

Here's my premise...
If we look at Tele-Paster's recent 5f1/5f2a thread, we notice 1k views and 36 replies. Let's assume 50 of those silent views are folks like me two years ago before my first build. Folks who wish to jump in to amp building but have trouble understanding/following the lingo.

If they (I) had a source that attempted to clear up the lingo then that would, maybe, encourage folks to jump in.

So for their edification (and mine), what terms could be related to, explained, or simplified to that end?

For example..
Control grids are called GRIDS but screen grids are called SCREENS. They are both grids
Across means parallel.
Power resistors are Plate resistors
Power rail resistors are dropping resistors

please add more...:)
 

owlexifry

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Feb 10, 2021
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276
Location
Adelaide, Australia
I still struggle with concepts and terminology.
With no previous exposure to electronics, I find it amazing that, in amps, there exists AC and DC current in the same wire, at the same time, and going in different directions.
Current flow, apparently, is opposite to electron flow. We send things to ground but that is where the electrons come from!!
if you haven’t already, i recommend giving this website a good read through:


rob explains things very well for the layman
 

dan40

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Aug 19, 2015
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Location
Richmond Va
Power resistors are Plate resistors

Many circuits, such as old Fenders, used standard 1/2 watt resistors on the plates but you could certainly choose to use a larger wattage power resistor for reliability. Plate resistors in the preamp do not deal with as much current as the dropping resistors used in the power supply.

Power rail resistors are dropping resistors

The resistors used in the B+ rail do drop voltage and decouple each stage so this is the spot that 2-3 watt power resistors are generally used. Many older amps got away with using standard 1 watt resistors in this spot but many builders these days choose to use a larger power resistor here for reliability and better heat dissipation. The screen grids on the power tubes is also another spot where you would want the higher rating of a power resistor because there can be considerable current on the screen grid when pushing the amp into heavy overdrive.
 
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Wally

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Mar 17, 2003
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Lubbock, TX
and at the top of the list of sections
there….

I see that AIken refers to control Grid as ‘grid’. He uses screen grid and suppressor grid for the other two grids in a pentode..,or beam tetrode. for simplicity with regard to that type of tube. In a triode, there is only one grid. When speaking of pentodes or beam tetrodes, I prefer to use ‘control grid’ to guarantee the lack of confusion. Ommv.
 
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