pouët.net

Really stupid idea for a wild prod:
Is it possible to do modified discreet cosine transforms with vacuum tubes? In analogue?

It probably is, but it would take you years and lot's of power and space.

Indeed, it would be huge and hard to maintain.

ENIAMP?

if you own a personal nuclear power plant, yes, it is possible.

it can be done without vacuum tubes -- use mechanical integrators: http://www.tatjavanvark.nl/harmonium/

trc: Sounds like my penis.

but HOW to efficiently encode binary data on a physical support, without need of integrated circuits? Old memory modules come to mind... xD
...hah, not really small!

Interesting question anyway... I think it wouldn't be possible, at least NOT in real time, due to physics constraints. But you could precompute it and store in analog format on some vinyl disks or magnetic tapes, just like in the good ol' days (where to listen to a second of low-quality mono audio you had to wait for like 10 minutes, or maybe more).

Anyway, some wild productions are listed here: http://en.wikipedia.org/wiki/Computer_music#History
also http://120years.net/machines/rca/index.html
or http://120years.net/machines/software/index.html :)

Maybe the next step in electronics will be the nano thermionics, but today transistors rules!

instead of valves, would be pretty much simpler to use relays. they resemble the digital behavior of a cmos gate. creating a register bank with them is quite simple. and not that is less vintage and useless -.-

@Quintix and BDK: the key is ANALOGUE.
I know of two devices like that
First is vocoder, which takes frequency analysis in fixed points, minimum is 4, bigest one I've heard og is 16 channels (spanning 5 octaves). good for speech, but nothing else. now used as musical instrument.

The other thing is electro-mechanical instrument constructed in 1920's in soviet Russia, named "ANS"
It uses discrete (mechanic) sine generators, with exponential frequency step, something 6 or 8 steps per semitone, spanning 8 octaves. As an input it uses glass plate covered with tar, then written with stylus, leaving paths with variable transparency, thus controlling amplitude, the read-out mechanism is a light ray and spinning discs with printed bars, basing on principle of film sound tracks.

This machine might be capable of replaying MP3's if You printed the fourier sonogram on celluloid sheet an feed it into reading slot.

well, a is slightly more complicated than a vocoder...! The crazy problem being the _decoding_ with TUBES (how many UNIVAC centuries?) :D

The keyword in "Discrete Cosine Transform" is "Discrete", which is pretty much the opposite of analogue.
Good luck with that :)

discrete in time with analog calculations is still possible

not only possible, but used extensively in modern A/D converters.

anyway it will have to be precomputed on some analog hardware! No silicon allowed! :D

Hmm, Verilog for vacuum tubes circuits...!!!

(i meant analog support)

VerilogAMS?