You are here:

Audio Systems/Motorola Vibrasonic


I own the above reverb unit - actual model is EV5R, but many are close to this as to what I am looking for.  The chrome two-button unit that turns it on and adjusts the reverb has about 8 feet of cable consisting of 4 color wires (black, white, yellow and red).  They connect into the spring unit via a plug.  Someone cut off the plug and just left the wires.  I am trying to determine which wires plug into the proper sockets on the spring unit.  I noticed that you had a unit and wondered if you might tell me which goes where - ie:  Red - top right, black, bottom left, etc.
Thank you so much for any help you can provide.

Best regards,

Such an old unit. Finding the owners manuals and wiring guides is not likely.

Best way is to trace out the circuitry.  Two wires would be for driving the spring which would come from an amplifier output. The other two would be the pickup from the far end of the spring and would feed into the input of an amplifier stage for blending back into the main audio.  From there you could figure it out.

Hope this helps.  

Audio Systems

All Answers

Answers by Expert:

Ask Experts




Audio Design Engineer; systems, loudspeakers, cd/dvd players, etc. I am knowledgeable in all high end audio equipment and installations. MAKE SURE YOU GIVE A MAKE AND MODEL NUMBER AND CAR IF IT IS AN AUTO QUESTION. Note: I am getting some who ask good questions that take a lot of time to research but then the questioner fails to read the answer. Please don't ask questions unless you are seriously looking for an answer. If you find an answer to your question otherwise then let me know with your reply. Thank you.


Have been associated with audio design, standards, testing and component systems for over 40 years.

Life Fellow Member of Audio Engineering Society Life Senior Member of Institute of Electronic and Electrical Engineers

Review technical manuscripts for IEEE Spectrum Write occasionally for high-end audio publications


Past/Present Clients
Past Employee/advisor to several well known audio products manufacturers

©2016 All rights reserved.