Re: Toy Reverb microphone( was: RE: Megaphone etc.)

[Mike Curtis <wd6ehr@xxxxxxxxxx>]

> 
> Wouldn't it be possible to use this toy microphone (or its insides) to build a
> do-it-yourself and very cheap reverb unit? Reverb units tend to be rather expen-
> sive and this way you could build a nice little thing to experiment with.

The reverb spring mechanism itself is VERY similar in design to the toy
microphone mentioned here.  I've seen them as cheap as $10. for a nice
dual spring unit.  Dual spring?  Yup - even cheap reverbs use at least a
dual spring.  It gives a much broader, spacious echo.  Good units have 4
springs. 

Of course, there are electronics required to make this work - a preamp to 
boost (usually) line level signal up to the power (yes, power!) required 
to drive the send transducer, and another preamp to take the weak signal 
from the receive transducer and bring it up to (usually) line level.  
there will (usually) also be a "mix" control, balancing the original 
sound with the delayed sound for the desired reverb effect while keeping 
the volume reasonably steady.

"Electronic" echo units are popular today.  There are analog and digital 
types, with the digital units being more precise.  Many prefer the more 
distorted ("softer") sound of analog delay units to the more precise 
("harder") sound of digital delays.  Neither is a substitute for the 
mushy and VERY analog  sounding spring reverb, even though digital delays 
may claim to have a "spring reverb" effect.

But getting back to your question - yes, you could build a cheapie reverb
out of that, using a small amplifier, speaker, and microphone.  Then you'd
have to mix the reverb'd sound back in with the original somehow.  And if
you play with significant volume (loud), you'd likely have more feedback
problems than before.  It'll probably want to be ensconsed in an airtight
box to keep out extraneous noises.  And you'll definitely want to suspend
the echo-mike, speaker, and pickup mic (the last 2 would be called
"transducers" in tech talk) using springs, rubber bands, or some such. 

If you build it, let us know how it works.  I don't expect it will sound 
as good as a professional reverb - but you might like its sound (these 
things are a matter of taste, you know :-)

And if you need a little technical help along the way, feel free to drop me
a note off list.  I'm sure the other "tech-types" on the list will extend
the same offer. 


 --  mike curtis
wd6ehr@xxxxxxxxxx