Joel Koltner wrote:

Are crystal earphones called that because they're used with crystal radios, or
because they really do have some sort of crystal in them (seems unlikely)?

---Joel



Not at all unlikely :-) Crystal earphones are piezoelectric devices
- the small electrical AF signal produces a small mechanical
movement. These devices have very high impedances so are ideal for
extremely low power circuits such as crystal sets.
See also crystal cartridges for playing records, these were some
what chunkier and would produce a lot of output and a typical cheap
record player might consist of a crystal cartridge (pickup) driving
the grid of a tridode / pentode arrangement (EL86 I think).



Charlie.

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