This is one approach, you'll need to read the test to see what they are doing.
http://www.diyaudioprojects.com/Tubes/6418-Tube-Preamp-Headphone-Kit/
http://www.diyaudioprojects.com/Tubes/6418-Tube-Preamp-Headphone-Kit/
An inefficient way is to put a lot of idle current thru the fet and reduce the source resistor to a very low value. This will flatten the battery quickly though, and need a big heatsink.
I can't be bothered with the specifics of this, it is more trouble than it is worth. Just use an LM386 power amp chip after a preamp triode, that's easiest.
It's been a long day...Love the attitude. You're going to work out well here.
Welcome!
Chris
The use of two tubes is an aesthetic design choice. I don't need the LEDs coupled on to the B rail either.
Is there any purpose to coupling the output at one anode to the grid of the next for two stages of amplification?
Respond if you want, but I may or may not respond for a few days. It seems I'm doing something that Einstein once described as "hunting for birds in the dark in an area with very few birds".
I, this entire time, have been trying to create a circuit that I could put in an enclosure and call my own. That's the reason I haven't gone out, bought a premade kit and just assembled and soldered it. Well, seems like I've hit the point where the plans carry little or no feasibility and everything I try to draw up or do differently end up creating another error, so I'm going to take a couple days to reevaluate whether I want to continue trying my hand with these projects and amplification ideas.
Regarding the schematic Chris posted earlier (power supply), with two 100uF and one 100nF caps for ripple filtering, can the 100nF be omitted safely?
The 100nF cap is a decoupling cap that should be placed close to the supply side of the plate resistors. There's no good reason to omit it. They're dirt cheap!
Chris
Haha. Nevermind that statement, I found them, but they had to be backordered. I was sitting to myself thinking "you have 5,200 of everything else in stock!"
and for whatever reason, apparently American convention is to make believe the nano-farad convention doesn't exist. I can't honestly be bothered to wonder why.
<snip>
But for example, why is it I can't just put a bunch of resistors on the tail end of the circuit to lower its impedance?
Would that work (at the cost of sending power through the floor)?
That makes more sense.Vacuum Tubes are inherently Hi impedance devices. As Kris explained to you earlier, they can be viewed as an object who's resistance between the Cathode and the Plate is varied by voltage changes between Cathode and the Grid. Since they operate with relatively high voltage and low current they are high impedance devices.
BJT's, are current controlled devices that work with much lower voltages and conversely with higher currents. They are much lower impedance devices than vacuum tubes.
I understand that, and that was not what I was asking.The value of the plate load resistor is related to the conductance of the tube but Kris covered this with you already. I see no point in rehashing it.
I've lived there, and I've been learning from not only it, but other sites, but the key to understanding is experimentation, and I don't have a wide selection of components to work with, so most of my questions are fulfilling that role.As I've stated repeatedly, our tutorial section covers all of this in great detail. Please visit it.
Your amplifier was not intended to be a power amplifier. For this reason a transformer is not an option for you.