Question about stages
Moderators: pompeiisneaks, Colossal
Question about stages
I am fairly new to the amp building game, but I would like to know more about how to identify stages in an amp circuit. There is lots of talk about Gain stages, pre-amp stages, phase inverters, etc. How do I identify those stages in the circuit? What am I looking for? I've included the schematic from Nik at Ceriatone and wonder if someone can tell me where each stage is located.
			
			
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						Re: Question about stages
Take a look at a real schematic, it will be simpler to follow for what you are after. Go to the trainwreck files section and look at the schematics there.
 
By convention the stages read from left to right.
To find your stages look out for this:
each stage will be separated by a coupling capacitor which has to block the DC / B+ at the plate of the tube and only pass the AC signal on to the next stage.
Those coupling caps are like the doors to your next stage and the pF / uF value of those coupling caps can really impact the sound and performance of the amp too,
best,
tony
			
			
									
									
						By convention the stages read from left to right.
To find your stages look out for this:
each stage will be separated by a coupling capacitor which has to block the DC / B+ at the plate of the tube and only pass the AC signal on to the next stage.
Those coupling caps are like the doors to your next stage and the pF / uF value of those coupling caps can really impact the sound and performance of the amp too,
best,
tony
Re: Question about stages
Fully awesome beginner thru intermediate book: The Guitar Amp Handbook by Dave Hunter.
			
			
									
									
						Re: Question about stages
Actually I don't know how to read real schematics very well and only find them confusing. I guess I was hoping someone could label them on this layout so I could get a rough idea.
			
			
									
									
						Re: Question about stages
Been reading that book and have learned tons, but still I don't know how to identify the various stages of an amp just by looking at it. I can see where the preamp stages are and the power stages but where is the phase inverter in a given stage or identifying a plate resistor?
			
			
									
									
						Re: Question about stages
jckid649 wrote:Been reading that book and have learned tons, but still I don't know how to identify the various stages of an amp just by looking at it. I can see where the preamp stages are and the power stages but where is the phase inverter in a given stage or identifying a plate resistor?
Phase inverter in the Ceriatone layout you posted is right before the output tubes, which is typical. From left to right, count over to the third noval (nine pin) tube socket ...... it's closest to the octal (eight pin) output tubes.
Re: Question about stages
Thanks. Is there any kind of info out there that can help a novice identify each part such as a plate resistor or a cathode bypass capacitor in any circuit in laymens terms?
			
			
									
									
						Re: Question about stages
Daves book is great but he still uses a vocabulary that is a little beyond a novices reach on some topics
			
			
									
									
						Re: Question about stages
You really need to learn to read a schematic.  A layout tells you how to physically place the parts; the schematic tells you what is happening electronically.  Until you can read a schematic and understand it, you will never progress past the paint by numbers stage.  Find a book or tutorial on basic electronics--there should be tons of that on the web.  Once you start to learn it, then some things--like plate resistor--will become self-evident.
			
			
									
									
						Re: Question about stages
Yes here is some info.
			
			
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						Re: Question about stages
Also we have a sticky in the Tech section called reading material on steriods.
https://tubeamparchive.com/viewtopic.php?t=9023
			
			
									
									
						https://tubeamparchive.com/viewtopic.php?t=9023
Re: Question about stages
Get a 5F1 schematic and sleep with it.  No PI but learning every component on the 5F1 will give you a foundation to start from.  Usually "stages" are from left to right.  Plate resistors connect directly to plates which are almost always drawn as the upper-most symbol in the tube-stage.  Plates are drawn as a line or a rectangle.  Cathodes usually an upside-down L and usually on the bottom.  
http://www.el34world.com/charts/Schemat ... _schem.pdf
			
			
									
									http://www.el34world.com/charts/Schemat ... _schem.pdf
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Re: Question about stages
I learned by having 
1. Clear gutshot
2. dead on layout
3. schematic.
4. That graphic Mark posted of the JTM board components names
			
			
									
									1. Clear gutshot
2. dead on layout
3. schematic.
4. That graphic Mark posted of the JTM board components names
Signatures have a 255 character limit that I could abuse, but I am not Cecil B. DeMille.