Help with analog circuit design

ANDONG

Joined Dec 5, 2023
2
Design an audio signal amplification circuit using a triode.It is required to amplify the signal without distortion:

1. the signal source voltage is 10mV and the signal source internal resistance RS = 500Ω;

2. Amplification 1000 times;

3. Load resistance RL = 8Ω

Ian0

Joined Aug 7, 2020
9,531
Design an audio signal amplification circuit using a triode.It is required to amplify the signal without distortion:

1. the signal source voltage is 10mV and the signal source internal resistance RS = 500Ω;

2. Amplification 1000 times;

3. Load resistance RL = 8Ω
The absolute maximum gain you will get from a triode valve is the value of μ.
There are no triodes with μ>125.
You would struggle to get a gain of 1000 from a pentode.
No triode can drive an 8Ω load. You would need a transformer.
Read Merlin Blencowe's book if you are interested in valve design.
https://www.waterstones.com/author/merlin-blencowe/1076386

WBahn

Joined Mar 31, 2012
29,885
Design an audio signal amplification circuit using a triode.It is required to amplify the signal without distortion:

1. the signal source voltage is 10mV and the signal source internal resistance RS = 500Ω;

2. Amplification 1000 times;

3. Load resistance RL = 8Ω
Where are these requirements coming from?

What does it mean "without distortion"?

There WILL be distortion, you need a spec on how much distortion is acceptable (which included indicating what kind of distortion).

ANDONG

Joined Dec 5, 2023
2

Papabravo

Joined Feb 24, 2006
21,029
This is homework help, not homework done for you. You need to show your best efforts at developing a solution. A good start would be telling us what you already know.

crutschow

Joined Mar 14, 2008
34,074
2

BobTPH

Joined Jun 5, 2013
8,686
The absolute maximum gain you will get from a triode valve is the value of μ.
There are no triodes with μ>125.
A regenerative RF circuit can attain ridiculously high gain with a single triode or transistor.

But certainly not with no distortion.

Ian0

Joined Aug 7, 2020
9,531
A regenerative RF circuit can attain ridiculously high gain with a single triode or transistor.

But certainly not with no distortion.
I learned transistors first, and valves later out of curiosity “what are these weird high-voltage JFETs in glass tubes all about?”.
I have heard of regenerative circuits, but the TS did say “audio”, and regeneration (usually from microphones) in audio is not usually a good thing!

panic mode

Joined Oct 10, 2011
2,682
no amplification is possible without distortion. i think the question is worded poorly and should be clearer (no clipping etc.)

Papabravo

Joined Feb 24, 2006
21,029
Good 2!!

I thought about making that reply, but I decided against it since I may be on thin ice with the mods for some of my other posts that garnered less than congratulatory responses.