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Hoffman Amps Forum image Author Topic: Radio Shack Realistic Pro-verb  (Read 10708 times)

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Offline passaloutre

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Radio Shack Realistic Pro-verb
« 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.

Offline passaloutre

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Re: Radio Shack Realistic Pro-verb
« Reply #1 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.

Offline passaloutre

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Re: Radio Shack Realistic Pro-verb
« Reply #2 on: December 02, 2021, 01:13:39 pm »
Anyone?

Offline Willabe

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Re: Radio Shack Realistic Pro-verb
« Reply #3 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.
 

Offline passaloutre

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Re: Radio Shack Realistic Pro-verb
« Reply #4 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
« Last Edit: October 02, 2023, 04:34:00 pm by passaloutre »

Offline Williamblake

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Re: Radio Shack Realistic Pro-verb
« Reply #5 on: October 03, 2023, 05:00:03 am »
Yup want to check the coils resistances. Can you post picture of the tank?

 


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