Measurement of electron charge $q_\textrm{e}$ and Boltzmann's constant $k_\textrm{B}$ by a cheap do-it-yourself undergraduate experiment

A simple circuit consisting of 4 low noise operational amplifiers with voltage noise lower than $1~\mathrm{nV}/\sqrt{\mathrm{Hz}}$ and one four-quadrant multiplier with full scale accuracy 0.5\% gives the possibility to determine the fundamental constants $q_\textrm{e}$ and $k_\textrm{B}$ with an accuracy better than 5\%. The Boltzmann constant is determined by measurement of thermally averaged square of the voltage of a capacitor and also by the spectral density of thermal noise of resistors. The electron charge is obtained from properties of shot noise of a photodiode illuminated by a lamp. For both the measurements we are using one and the same set-up. The cost of the 3 integrated circuits gives the possibility to realize the experiment in every high-school or university in the world. The analytic calculation for the pass-bandwidth avoids the necessity to use standard instrumentation as oscilloscope and sine-wave generator. We use only a LCR-meter, and a voltmeter, that is why the budget is less than 137 \$.