Dug up a neeto analog reverb...

[Hal]

About 20 (maybe 30?) years ago my dad built a radioshack kit (solder by the numbers!  No joke!) that was "electronic reverb" - its based on an SAD1024 BBD chip.  It wasn't working last time I tried it, and just put it aside.  SO I picked it up again, and "debugged" - the only problem was a bad solder joint on one of the BBD bias trimpots.  So I redid the joint, and first plugged it into my CD player...thats what it was made for (it has RCA connectors)

Sounded neet.  Obviously the guitar was next.

when I first plugged it in...SQUEEELLL!!!!!!!.  I turned down the "feedback" knob, and it was a bit more controlable, but the effect was very subtle.  I activated my preamp in my guitar, and it was a bit better.

The biggest problem was hum.  It has a built in power supply...(argh).  It adds noticable hum when on, even when on bypass (!!).  I'm pretty sure its 60 hz.  I'd need to redo the whole power supply if I want to make it into something more useful.  

Still, fun stuff.  It has 5 controls - depth, delay, and feedback, then "sepcial effect" speed and intensity.  When I move around the special effect pots it make strange sounds, but otherwise, I can't really tell what its doing.

the moral of the story: I still believe in BBDs.  No matter how "bad" the construction was, it still sounded cool, and even good...

[Mark Hammer]

That would have been the application circuit that came with the SAD1024, when they sold it.  Radio Shack would pack these folded up information sheets inside the package with the bubble-wrapped chip.  In Canada they had to be in English and French, so the print was small to pack it onto the needed space.  I have no idea what happened on the other side of the border.  Would I be correct in suggesting it used a 555 and a couple fo CMOS chips for the clock?

[Mark F]

If the circuit is 20-30 yrs. old you may try replacing the electro's in the power supply & that may help you with the 60 Hz. hum.

[Hal]

If the circuit is 20-30 yrs. old you may try replacing the electro's in the power supply & that may help you with the 60 Hz. hum.

I'm pretty sure the hum is comming from the transformer, since its injected even when the reverb is "on" but in bypass.

and yes, I think I do remember seeing a 555 in there, but I'm not totally sure.  The whole thing was a radio shack project, though...You buy the enclosure and decals and PC Board, and then buy all the components (all available at radio shack) seperately.  The packs of resistors were $.29 back then :-D