Distorted audio on an old transistor radio cassette

[Craig]

I just want to ask a question here about the configuration of transistors VT2 and VT3. What is it used for, what is it's purpose? I'm not offering a solution just trying to refresh my memory. I'm old. lol Thanks guys

 

[dorke]

The VT2 -VT3 configuration pair is a differential amplifier ("long tail").
It has 2 inputs : (one is used for feedback of the output through R31 to TR3 base),
and 1 output : to feed the final stage from TR2 collector through C25.

You may think of it has a "simplified" op. amp.