[sdiy] monolith ics

[Eric]

>This reminded me of something I found in an old metal Bandaid box. Thought
>it was curious enough to make a 15 minute web page about it.
>http://www.musicsynthesizer.com/Circuitry/Ampec.html

Centralab started making Ampecs during WWII.
I have an ad for them from 1946....same circuit,
same tube lineup.
People sometimes used them to make homebrew
hearing aids---driving a crystal earphone.
Also used on crystal radio sets, etc.
Kind of costly, though--I think they were
$20 when that was real money....

Printed circuits and thick-film ICs are
hardly new ideas.....


Eric Barbour
METASONIX