Check out the YouTube video for more details:

What is it?

Turns out this is a 3 channel high output impedance DC to 1.5Khz amplifier. I'm not an expert on when you might need something like this, but two use cases I could imagine:

• Testing ceramic capacitors DC bias capacitance change with voltage.
• Driving small piezo / ceramic transducers.

If you have other ideas please let me know! Below are some pictures, and test results.

Inside Peek:

Approximate Specification:

Being an amplifier, I figured I should try to understand its performance. This is specifically a 3 channel fixed gain amplifier with adjustable DC offset. So after measuring the DC offset range, the only two remaining important parameters were frequency range and output impedance.

So after sweeping a signal generator through it, and measuring the output voltage drop under some loads, I came up with the resulting "datasheet" below.

Schematic

Below is a simplified schematic based on the major components on the board. The power supplies are simplified, but the critical AC/DC components are presented well enough to produce a simulation that matched the lab data collected.

Simulation

Using LTSpice, The circuit was simulated. The frequency response was close the the measured value, so it appears the schematic is close to accurate.

One more unknown piece of test equipment has now been documented into the forever living internet.