hi lwt,
This is the original source data, it works according to their specification.
Note what it says about the V gain less than unity.

E
View attachment 280582

What did you change apart from R12 value in order to make it work? Also, what I'm getting from this is that this is only a tone control circuit not a preamplifier right?

 

Why did you change the value of R12 from the value in the original circuit ? With the original value that stage would provide some gain. With the value that you used it would attenuate the signal.

Les.

That was a mistake on my part, nothing intentional!

 

Hi Eric, I am asking the TS. The high value of the emitter resistor in the output stage of the circuit in post #1 was the first thing I noticed that would cause the signal to be attenuated. The 2.2K value in the circuit in the link from post #17 make more sense as it would give a voltage gain of about 4.

Les.

 

2022 is the 70th anniversary of the Baxenall tone control circuit, which made your circuit obsolete.
Why don't you study the Baxendall circuit, because it is rather easier to understand?
https://sound-au.com/dwopa2.htm

 

hi @LesJones.
This is what the AC analysis shows for the full range of the Base and Treble controls.
E

 

I see that your copies of the original schematic have serious errors:

 

hi agu,
Post #25 have the original values as posted on the TS's link.
E

 

Would love to be able to design a circuit all by myself. Unfortunately I don't have the knowledge for that.

Yet the course you are taking would appear to assume that you should be able to do so by this point. You might need to retake the course. If you do, you would be in a position of knowing what you need to learn the second time around so that you are better prepared to focus and pay attention to the right things. The alternative is to limp through via excessive help from others and end up in a course you are even less prepared to succeed in.