Repairing/Hooking up a fairly unmarked spring reverb. Origin unknown.

[LukeeeeBennett]

I'm trying to wire this up to essentially use it as an effects pedal. I notice that they have labelled 'Input' on the chassis where the green and black wires go to the spring transducer and then 'Output' on the black wire going to the other transducer. They have 5 test pins on the board where of course I assume you hook up your lives and ground, but I can't work out which is for the input and which is for the output and then there's also a third test pin?

Any help would be greatly appreciated. Will post most pictures if needed.

 

[alec_t]

Something here may help?
**broken link removed**

 

[remon7]

Well Well !!! Dont worry
Sounds very interesting and helpful! Thanks for sharing LukeeeeBennett.
You need to how to repair first now Gotta giving you some tips at frist you have to go Spring Reverb Tanks and if you found some critical circuit error then use electronic calculator . If you want more information just email me i will reply. i'm waiting for your reply. Let me know if you have any problem.
Thanks
Engineer A.h. Remon

 

[remon7]

it seems quite simple but need proper knowledge on other components.
Thanks

 

[dr pepper]

Not certain but that looks a little bit like a McGregor mixer amp reverb unit.

 

[remon7]

McGregor mixer amp reverb unit means? i dont understand what is this any brand name?

 

[dr pepper]

I just realised your in malaysia, Mcgregor amps are local to me, that said they get all round the world.

Heres their site:

**broken link removed**

 

[peethagoras]

re that big capacitor

Hello Luke.

I seem to recall that same spring unit was sold by Maplin many years ago. As the thing hardly changes, perhaps there is still some info on using it. The English magazine Practical Electronics used the same unit, in many projects. The spring is quite short, this means the sound produced will not have a great deal of reverb. If you ever stumble on an old Hammond organ, some of them had a very long reverb unit which you might be able to salvage.

As for connecting the board, it is best to trace the circuit and draw it on paper - that way you end up with something to go on. Use a Ohm-meter to identify which pin connects directly to that big electrolytic capacitor on the right hand side *****- it looks like a power supply filter capacitor. On pin should connect to the positive lead, and on pin to the negative lead. If you manage to identify the two supply pins (positive and ground) you might find a working voltage printed on the side of the big filter capacitor, use that value, less 20%, as your supply voltage. Example: the capacitor reads 12V WKG (12 volts working limit) so you are safe to use a 9 volt supply.

That accounts for two of the pins, the other three could be either for a volume or 'tone'control, or maybe even a kind of 'reverb-presence control'.

Regards.


***** when I said right hand side, I meant from your perspective in the image, not the readers perspective.