MUCH LATER NOTE (July 2003): I recently obtained a Peavey
"Microbass" 20 watt amplifier. Using the Radio Shack
"buzzer" double piezo element pickup described here, I was
VERY impressed to see that Doodle-bass #3 with this
pickup/amp setup is a truly excellent sounding and playing
EUB (Electric Upright Bass). This thing would work fine in
any situation where an upright bass or EUB was called for.
I've had the opportunity to play a commercially made UEB and
it held no edge over the Doodle Bass #3 with double piezo
pickup. The pickup did not overdrive the Peavey amp at all
and no matching or preamp circuit was required between pickup
and amp. Not (yet) having a long end-pin on #3, I find it
very convenient to play sitting down, with the pot resting on
the floor at my feet.
This "Doodle-bass" plays SO smoothly and is such a pleasure to
play that I figured a pickup would enable it to be useful in a
band situation, so I made an extremely simple piezo, acoustic,
contact double-pickup. The piezo transducers can be bought from
any Radio Shack store for $1.49 each. The Radio Shack part number
is 273-073A (they sell several different models, which should work
just as well) and the the plastic cases must first be completely
removed -- this is not easy without damaging the transducer
element. The best way is to take a bare hacksaw blade and
carefully cut all around the top perimeter of the plastic - so as
to remove the entire top. Then (at the hole where the two wires
enter) (clip off the wires first - they aren't needed) saw through
the "band" (the side). With a pair of pliers, bend & work off the
plastic "band". The actual piezo transducer is quite fragile so
take care not to bend or otherwise insult the element any. When
this is done, the piezo transducer should release.
After considerble experimentation, I finally have the Radio Shack
piezo contact pickups positioned "properly" and working VERY
nicely. The objectionable random finger scuffs and other noises,
that were quite noticeable in earler experiments, are gone -- the
tone/sound and volume are now excellent and the setup works/sounds
every bit as good as I'd hoped it would. Very nice bassy sound -
well balanced high to low - not trebly at all and as loud as can
be (if desired) (the most my ears will stand is with the amp
volume set at 1/4).
What made the difference is that the piezo elements are now
sandwiched between the bottom of the bridge and the sound-board.
The weight/pressure of the strings bears directly on the piezo
element via the bridge (the crystal side of piezo element is
positioned facing up, with the brass side contacting with the
to see a drawing showing this simple piezo transducer pickup setup
The pickups being pinched under the bridge adds slightly to the
string heigth, but not enough to be noticeable while playing. At
this point I've only tried this setup with doodle-bass versions #2
& #3 (the ones tuned EADG - identical to a big standup bass).
I took pains to be certain that the piezo elements laid
absolutely flat, with no solder globs or anything else sticking
up. With the element very flat, I've experienced no tendency for
it to crack, even with all the pressure on it from the bridge &
NOTE (mid 2002): I recently rigged up a doodle-bass for a friend
who has a Gorilla GG-20, 20 watt amp. These little piezo elements
really kick out the voltage, and the output of the piezo pickup
was too much for the Gorilla --- it made for a distorted sound,
particularily on the lower two strings. This was completely cured
by inserting a.002 microfarad capacitor (a fifty cent Radio Shack
item) in series in the bass to amp line. This reduced the output
of the piezo element to the point where the distortion was
completely eliminated. The amp was still more than loud enough.
This capacitor had no adverse effect of the instrument's tone or
.002 microfarad capacitor
to piezo pickup <------------|(--------------> to amplifier
center conductor of cable
Nothing has to be done to the ground side (shielded wire) of
Clark Rowden sent me some additional information pertaining to
amplifying the doodle-bass.
Click here to view this.
Mackinac Straits, northern Michigan
to return to my the main doodle-bass article