The Telharmonium dated from the "if only we had gain" era of pre-electronics. The thing was a huge collection of sizable AC generators running at different frequencies, run through a keyboard, and mixed with transformers. With no way to amplify a small signal, there was no way to downsize the thing. Once amps were invented, the Hammond Organ, with its tone wheels, was the same concept in a piano-sized package.

History of pre-transistor electronics:

- If only we had voltage.

- If only we had current.

- If only we had rectification.

- If only we had gain.

- If only we had frequency.

- If only we had power gain.

- If only we had reliability.

- If only we had precision.

- If only we had counting.