Hoffman Amplifiers Tube Amplifier Forum

Other Stuff => Effects => Topic started by: passaloutre on November 22, 2021, 05:30:44 pm

Title: Radio Shack Realistic Pro-verb
Post by: passaloutre on November 22, 2021, 05:30:44 pm

Find this thing in an antique store. It claims to be a "solid state reverberation system". I can't find a schematic anywhere.

I get dry signal through when I plug into the "mike" input, but just wind noises when I turn up the reverb mix pot.

There's a nice clean eyelet board inside, and some very old electrolytics that I'll need to change. Would love to find a schematic of anyone has any leads.

Title: Re: Radio Shack Realistic Pro-verb
Post by: passaloutre on November 22, 2021, 05:33:28 pm

Note, this doesn't seem to be the same as the later Radio Shack analog reverb, which I believe was a bucket brigade echo.

Title: Re: Radio Shack Realistic Pro-verb
Post by: passaloutre on December 02, 2021, 01:13:39 pm

Anyone?

Title: Re: Radio Shack Realistic Pro-verb
Post by: Willabe on December 02, 2021, 03:43:46 pm

Sorry.  :dontknow:

Maybe someone will see this post given some time who's worked on one?  :dontknow:

Keep checking back every once in a while.
 

Title: Re: Radio Shack Realistic Pro-verb
Post by: passaloutre on October 02, 2023, 04:14:19 pm

I finally got a chance to spend more time on this one. Opened it up, cleaned the pot, played around, and drew up a first draft schematic.

I've attached some photos of the interiors. It's clearly been modified, three transistors have been changed (solder-spliced to the dead legs of the originals), and one (presumably original) four-leg metal-can transistor that I can't identify or figure out the pinout. The replacement transistors say "CBS 1232" on them, but I can't find a datasheet for that part, and I can't make out any markings on the four-leg guy.

The filter capacitors also appear unoriginal and the values seem to have been chosen at random as far as I can tell.

Anyone care to make sense of my schematic? I've double checked it with my meter, but I'm sure there remain errors. What's the deal with the four leg transistor?

EDIT: I meant to say, after playing it a bit, and running the pot back and forth a hundred times, I do get a weak reverb signal from it, as well as a slightly boosted dry signal.

More photos of the guts are here: https://imgur.com/a/527Kr9i

It has a tiny tank inside, but I don't know how to measure the coils. I'd like to get it back to it's original shape, but if not I suppose I can build a different reverb circuit into the box, maybe with something like this: https://www.tubesandmore.com/products/reverb-tank-accutronics-amc2bf-2-spring

Title: Re: Radio Shack Realistic Pro-verb
Post by: Williamblake on October 03, 2023, 05:00:03 am

Yup want to check the coils resistances. Can you post picture of the tank?