Let's play "wtf is this thing?"... Garage Sale Mystery

[wtwu]

Any ideas?  I can't get any sound out of it.

[duck_arse]

allow me to be the first to say:

"burst box".

like that old greek brass "clock" thing, no-one knows how these work. how much was it?

[Hemmel]

I love those floating caps and diodes.
Or are they on a small board ??

[wtwu]

they are on a small board... but practically...

I bought a pile of random stuff from this estate sale for $7.  The daughter of this 'acid jazz' drummer was trying to get rid of a bunch of his stuff.  He had tackle boxes full of cable mods and some good small tools, but everything that was enticing like some vintage midi equip, she had real prices on.  This box felt like it was empty, but definitely worth the risk...

[timd]

Could it be some type of DI or filtering? Strange only one 1/4 jack.

[candidate]

headphone amp

[Quackzed]

+1 headphone amp, or some kind of stereo amp ...

[Johan]

On pic 3 and 4 there is an ldr next to the lamp...some kind of limiter?

[wtwu]

+1 headphone amp, or some kind of stereo amp ...

that's what I saw at first too.. since it doesn't work to test, I turn to the board...

[Govmnt_Lacky]

Find it odd that if it is a headphone amp that it would have the outputs (assuming that the 1/4" jack is NOT the output since it is mono) on 3/8" or 3mm jacks 

Maybe it is a signal splitter/amplifier? Looks like they used a 12VDC power source via the transformer.

[bluebunny]

Those little jacks look mono too.  Only one sprung contact and only two wire connections.   

[Digital Larry]

Converts acid to jazz and vice versa?

[strungout]

Converts acid to jazz and vice versa?

Gues you gotta trace and draw a schemo If you're that curious that is...

[PRR]

Metronome is possible.

[MaxPower]

It's a... one of those doohickeys... Plug in your headphones, plug in your guitar, and plug in your cd player (cassette player) and jam along or whatever.

I have no idea what I'm talking about...

[tombaker]

Your new Tiny Giant amp enclosure?

But seriously it has two opamps:
http://pdf1.alldatasheet.com/datasheet-pdf/view/25572/STMICROELECTRONICS/UA741CN.html

So it's looking like a headphone amp or splitter, it does only have mono 3.5mm jacks which I don't see as uncommon if it were just a headphone amp, especially if it's as old as it looks.

[deadastronaut]

ldr?...strange device..

[Johan]

Lamp driven by the opamp closest to the pot, ldr with possibly heat shrinked resistor forming a voltage devider...i still think some kind of compressor/limiter...a 741 or two wouldn't make the best headphone amp...

[armdnrdy]

HHMMM....According to declassified files I received in accordance to the freedom of information act....I believe it's a NSA data collector.
or a headphone amp...or a metronome...or a.... 

[tubegeek]

I believe it's a NSA data collector.

Yeah, I've been seeing a lot of those at yard sales lately. They must've moved up to a new model.