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                  Frank Geiger


Customer Comments About Older Products
(Before 2019)

R.S. called from Michigan to say that the Tone Amp "worked great" on his aluminum rim banjo, and that he got the best sound with the tone amp attached to the coordinator rod, not to the aluminum rim.

H.L. wrote the following from Germany:  Hi Frank...The volume of my B&D Siverbell No.3 increased and got more punch and definition at the mid- and high range. Furthermore the notes seem to ring more fully.  In other words, this Tone Amp of yours was a good investment.

B.B. wrote the following from New Mexico after installing his first one, then ordered three more:
“The banjo plays great and sounds quite good since the renovation but it does have less volume than two other Mastertones I have.  With the Tone  Amplifier added it has distinctly more volume and tonal richness up and down the neck.”

Jim Riley, noted Jazz Band Tenor Banjoist & Professional in Raleigh, N. C. wrote:    Just wanted you to know that I tested your tone amplifier at two gigs on Saturday, and was completely satisfied with the results.  I again asked the other band members for their opinions, regarding how my banjo sounded, and received their approval.  This time they unanimously confirmed that my banjo  sound was noticeably bright and clear.  

I sent customer H.L. in Germany one of the new "Blaster" tone amps in a "Travel Caddy" and asked for his comments.  This is his reply:  "Hi Frank, I am very pleased with the new power tone amp. It's indeed more powerful, and with my B&D SiverBell all frequencies seem to be more strong.... For Irish Music/Sessions it's really grand. - I think  your "Tone Amp Travel Caddy" is a very useful tool and it works well. Thanks a lot. All the best..." Australia wrote the following after using it in his B&D Silverbell tenor: The extra volume of sound is amazing with a nice prolonged ring added to my Banjo, and it can be used for other stringed instruments.

From K-E-W in Chicago who wrote the following after implementing the bending modification to his Tone Amp:  "Hi Frank,  I implemented your last suggestion to bend the tone devise, and I have to admit. I  think my banjo is now too loud for my little apartment.   I LOVE IT!"

G.B. in North Carolina wrote the following after installing the Tone Amp in his Clawhammer Banjo made from a pre-war Bacon and Day tenor pot without tone ring which he plays with the resonator off:  "Frank...I received the stick-on tone amp for my banjo.  I can't believe how well it works!!  No tone ring but now sounds like there is!"  

New Customer Posting on "":  Just attached my tone amp.....greatly improved the sound level and quality.  I am now a believer!

Comment rom N.L. in France:  “Simply amazing how it can improve the timbre of the instrument. With a metal part it was good. But I added the 2 others and I heard more harmonics.  Belle invention, Frank!”

Comment on new Butterfly Amp in his Bacon Banjo from Tone Amp Customer in Germany:  "Hi Frank, The 'Butterfly Timbre Amp' makes the sound of the E- and A-string of my Bacon Day Shortneck more crisp. The sustain improved , but is not too long for Irish Music. Overall I now like the sound of my B&D even more.  

April 10, 2019   "Recent Improvements To Dual Tone Amp Design and Installation"  

     Three significant improvements to the Dual Tone Amps were recently discovered but are not yet shown in the downloadable drawings.  All three are extremely easy to make, greatly improve the sound from the amps, and are described in the drawing and explanation below.


     The first change is that the long input tape to the center staple, which carries surface acoustic waves from the rim to the center staple of each amp, no longer extends over the bottom of the banjo rim.  It was learned that extending the tape around the bottom of the rim, as shown in some earlier drawings, degraded sound quality.

     The second change is the addition of four very short segments of tape over the four staples on the bottom edge of each amp which also stick to the rim.  These short strips of tape help ensure that each staple's point ends are held firmly against the banjo rim.  The staples will not act as amplifiers if this contact between staple and rim is not maintained.  The curvature of the rim tends to cause the staples to pull away from the rim because the paper tends to remain straight.

     The third improvement is to place both amps on the rim at a slight angle (approximately 10-degrees) to the banjo head.  This change in angle increases both volume and resonance from the banjo.  Why this occurs can be understood by thinking of the waves of audible sound as straight lines exiting the top of each amp at 90-degrees to the top paper or brass foil edge.  Each "line" of audible sound will hit the head at an angle, and at slightly different times, and be reflected onto adjacent waves.  This intersection of adjacent waves having similar frequencies causes amplification by the physics principle of "Constructive Interference", and the slight time difference hitting the head creates very pleasing resonance.  The angle of 10-degrees can be easily increased or decreased to achieve the amount of resonance desired for the particular banjo and style of music.

​     You are sure to be impressed with the improvement that these changes make to the sound of the banjo.

Frank Geiger Apr 10, 2019

November 29, 2017. Look For This Widely Available Substitute Tape That Works On Our Products To Pickup And Transfer Sound Surface Waves.

The tape that we use on our products to pick up and transfer sound surface waves is 3M Model 600 tape which is a clear acrylic tape.  It works very well and we measured its thickness at .003 Inch.  Unfortunately, this tape only comes in large rolls that require a large roll tape dispenser so is not widely available or economical if you just need a little bit of it.  Fortunately, 3M makes a similar tape that we have used and which, although it is slightly thicker at.004 inch thick, it seems to work well enough with our products.  You can probably find it in inexpensive small rolls at your local office supply store, drug store or other store that sells school supplies.  Be sure NOT to purchase 3M's "Magic Tape" which is sold in similar rolls with green plaid packaging because it won't work on our products.  Instead, look for 3M's "Gloss Finish Transparent Tape 1/2" Wide" in a Red Plaid-decorated dispenser containing 12.5 yards of transparent tape.  It may be attached to a card as shown in the photo below.