| Author |
Topic: How does a reverb unit work? |
Jim Cohen
From:
Philadelphia, PA
|
Posted 19 Mar 2005 8:38 pm |
|
Can someone give me a Layman's version of how a spring reverb works? Don't get too technical, just tell me what makes the boing-boing, 'kay?
Thanks,
Jimbeaux
(aka "Gerald McBoing Boing" - anybody remember him?) |
|
|
 |
Cliff Kane
From:
the late great golden state
|
Posted 19 Mar 2005 9:08 pm
|
|
| There's a box with long light springs (usually four or six of them). A circuit in the amp sends an electrical signal to a transducer that is connected to one end of the springs. The transducer converts the electrical signal to mechanical energy which causes the springs to vibrate. At the other end of the springs is a pickup (transducer) which converts the sprngs' vibrations back to electrical energy, which is returned to the amp where it is amplified and mixed with the orginal or dry signal. The echo is caused by the sustained and reflected sound of the springs' vibration. That's why if you bang against a spring reverb unit it sould like an explosion in an echo chamber. |
|
|
|
Chris Schlotzhauer
From:
Colleyville, Tx. USA
|
Posted 19 Mar 2005 9:17 pm
|
|
Jim, on my Nashville 400, the knob at the far right makes it go boing the more I turn it toward 10. I'm an expert at it, so you don't have to thank me.  |
|
|
|
Dave Van Allen
From:
Souderton, PA , US , Earth
|
Posted 19 Mar 2005 11:21 pm
|
|
| Quote: |
| aka "Gerald McBoing Boing" - anybody remember him? |
Gerald Mc Boing Boing |
|
|
|
Jack Stoner
From:
Kansas City, MO
|
Posted 20 Mar 2005 3:21 am
|
|
The original mechanical reverb "tanks" used by Fender (e.g. in a Twin Reverb) had two springs, one spring delayed the signal 29 ms (milliseconds) and the other spring 31 ms.
The springs also "vibrated" and thus the extended or decay of the delayed signal.
The delayed signal is then mixed with the original signal.
The Reverb control and it's setting determines the amout of delayed signal is mixed with the original and if it's turned al the way up it will "boing".
|
|
|
|
John Daugherty
From:
Rolla, Missouri, USA
|
Posted 20 Mar 2005 5:20 am
|
|
| Dave, I remember Gerald. He is the reason I use only electronic delays. We are a wee bit off the topic, but stuff like this just seems to "spring" from a steel players mouth. |
|
|
|
Jim Cohen
From:
Philadelphia, PA
|
Posted 20 Mar 2005 5:34 am
|
|
| Thanks, guys. And, Dave, I didn't realize that Gerald McB-B was a Seuss creation; shoulda guessed. |
|
|
|
Ray Minich
From:
Bradford, Pa. Frozen Tundra
|
Posted 20 Mar 2005 1:32 pm
|
|
| And the reverb mix between "reverbed" signal and the original or "non-reverbed" signal is called the corresponding wet/dry mix or wet/dry ratio I believe. |
|
|
|
Jim Cohen
From:
Philadelphia, PA
|
Posted 20 Mar 2005 6:37 pm
|
|
| Clarification: does the signal that passes thru the spring box "contain" a frequency/pitch, or is it a pure electronic signal that gets converted to spring energy and so what the pickup at the end of the spring box hears is just the pure sound of the springs, that then gets mixed with a separate musical pitch signal to create the illusion that the pitch is in a large room or tunnel? |
|
|
|
Dave Grafe
From:
Hudson River Valley NY
|
Posted 20 Mar 2005 7:50 pm
|
|
I'm not sure of your question regarding "pitch" in a space, Jim, but I'll try here -
The pickup changes the mechanical movement of the guitar strings into a fluctuating electrical signal. After preamplification, tone filters, etc., the reverb control allows some of this electrical signal to go to the reverb spring drivers, which change the electrical signal into mechanical impulses, the same signal that you guitar strings initially created, give or take a bit for EQ, etc. It's like speakers only driving springs instead of paper cones, and with MUCH less power.
The mechanical impulses travel through the springs at a slower rate than the electrical ones, and multiple reflections of the signal are constantly reflected back from the end of the spring, like ripples in a pond. It is this delay and these reflections that simulate the delay and reflection phenomena of a "live" acoustical space, be it large or small.
At the receiving end of the spring is another transducer, again turning the mechanical musical signal AFTER PASSING THROUGHT THE SPRINGS into an electrical one. This is the "wet" signal that you is mixed back into the "dry" original one, still in the electrical domain, and fed to the power amp and finally to the speakers, which turn the electrical signal back into a mechanical one.
It is not the sound of the springs themselves, but their mechanical delay and reflection properties that make a spring reverb unit work. Gerald might disagree with me on that, though... |
|
|
|
Tony Prior
From:
Charlotte NC
|
Posted 21 Mar 2005 1:54 am
|
|
Jim, why didn't you ask Wayne ?
t
|
|
|
|
