I'm attempting to design an amplifier for a class project. I do not want someone to necessarily solve this for me but just provide some insight. First, the design requirements: Requirements: Input impedance > 10k Ohms output Impedance < 500 Ohms Gain > 1000 V/V Vcc = 18 V Swing = 12V p-p f_low: 100 Hz f_high: 1 MHz load : 2k Ohms Background: At first, my partner and I tried just using some capacitor coupled Common emitters followed by an emitter follower. In spice we got the results we designed for but in the lab we had some very strange behaviors. No matter the input to the circuit (magnitude and frequency), we were seeing around a 5 MHz noise signal with about 100 mV on the input and 6 V on the output. We abandoned that design assuming there were some strange factors at play that we don't know how to account for due to all of the coupling and shorting capacitors. Our next design choice was to use a differential pair. This has the advantage (in my mind) of not needing as many coupling capacitors. The strange part about our design is that Vcc is 18 V instead of the normal +/- 9 V that you normally see. I have attached my ltspice schematic which simulates well. When we built the circuit though the first stage differential performed as expected. Then, when we added the second stage we had some clipping so we decided to check our DC bias values. We found that the current was splitting very unevenly on the first diff amp stage which of course causes issues down the line. Questions: Is this design just plain dumb? Is it even possible to design a differential amplifier with discrete components? We checked the Hfe of all the transistors available and matched them as best we could. When I try simulating with different beta values the gain is attenuated slightly but not as much as what we were witnessing. Any other general advice? Thanks! EDIT: those collector resistors should be 30K not 32K.