# The 'Simple' Problem that isn't (Op-Amps & TF's)

#### JJCrossbow

Joined Feb 22, 2012
3
Hey guys, I know I am new and this sounds like asking you to do my project for me but I assure you of 2 things, coming here is just once source of helping me find a solution and I already have some ideas on how to solve, but no solid answer.

Onto my problem, my project is: Analogue Based Gyroscopically Tracking Stereo Panning Headphones and my question regards the panning section of the circuit. (The last part remaining! This gets solved and my project gets built!)

This isn't particularly a complex response, but it definitely requires lateral thinking

Question: Recreate the following transfer functions using only analogue components (NO PIC's!)

Album of Transfer Function Graphs

My progress:

1. R2 and L2 are inversions of R1 and L1 respectively so creating them is easy enough If I know how to make R1 and L1 (using a inverter)

2. The linear gain and flat response section of R1 is simple enough with a linear gain op amp wit a 5V power supply so it clips.

3. Zener diodes as most likely going to be have to be utilised in some way to make the 'down' slope and used to create the offset seen in L1.

4. Someone mentioned a rough solution can be realised using FET's and Zener Diodes but didn't expand on how.

Anyway, that is pretty much everything I can think of, I'll add to this post if I think of anything else. Thanks in advance for any help you might give me!

#### JJCrossbow

Joined Feb 22, 2012
3
Solved: Win

#### jimkeith

Joined Oct 26, 2011
539
This is one approach--avoid zeners--use active clamps to establish limits--use summing amplifiers to establish thresholds

2nd circuit corrects goofs in the first

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#### jimkeith

Joined Oct 26, 2011
539
Note that the 324's come four to a chip