CBG with built in amp and speaker !!!

[Tom Caneschi aka TC]

Has anyone built a CBG with built in amp and speaker ?  I haven't been able to tame the feedback to a playable level. I put the pick up, amp and speaker as far away from each other as possible ... I'm sure some of you advanced builders know the fix ... Ideas  anyone.

[Scott Winburn]

I have built two like this.  My first "Jamplifier" was amplified by a piezo embedded in the bridge.  The bridge sat on top of a metal sauce pan thingy... which vibrated like mad and caused feedback.  Simply planting my pinky & ring finger on the metal prevents the feedback, so it's lucky I play that way anyway. 

 

The feedback loop was created because the sound from the speaker was vibrating the surface under that piezo bridge, which then gets amplified... and the cycle repeats, getting louder and louder.  So, on my second try i intentionally made the surface thick & sturdy so that it would not resonate much, the opposite of what you would want for an acoustic instrument.  This worked out quite well.  There is no feedback at all while playing, and only a slight feedback loop can be created during silence with the strings not muted.  

 

Hope that helps... good luck!
-Scott

[David L.]

Hi Tom,

 

There is an old thread here on the subject.

http://handmademusic.ning.com/forum/topics/mounting-a-minty-amp-in-the?

 

I like the onboard amp/speakers as it means you can get a nice little electrified sound with a magnetic pickup.  I find volume is limited though and on my last build put it on the side nearest my face.

 

The volume from an onboard miniamp/9v battery is limited so I decided it was mainly for my benefit so have it pointing at me - this helps to reduce feeedback.

 

The other huge improvement are the undersaddle piezo rods with the "passive" preamp off ebay

 

I recently put one in a 3/4 size classical guitar

It is amazing (just search on ebay for "piezo passive preamp" and you should find it) - I have bought several off  ebay and it works well as a fasive filter for tone.  No sound board noise and you can put it through effects the same as a magnetic pick up.  On the top photo you can see I used one of these wired to a disc under the brige inside the box - it helps to control it so the piezo only feedsback at the highest volume.

 

Good luck with a solution,

David

PS any chance of a photo of the cigar box guitar?

[Randy S. Bretz]

Gitty sells the same pre-amp rod piezo set up


David Lloyd said:

Hi Tom,

 

There is an old thread here on the subject.

http://handmademusic.ning.com/forum/topics/mounting-a-minty-amp-in-the?

 

I like the onboard amp/speakers as it means you can get a nice little electrified sound with a magnetic pickup.  I find volume is limited though and on my last build put it on the side nearest my face.

 

The volume from an onboard miniamp/9v battery is limited so I decided it was mainly for my benefit so have it pointing at me - this helps to reduce feeedback.

 

The other huge improvement are the undersaddle piezo rods with the "passive" preamp off ebay

 

I recently put one in a 3/4 size classical guitar

It is amazing (just search on ebay for "piezo passive preamp" and you should find it) - I have bought several off  ebay and it works well as a fasive filter for tone.  No sound board noise and you can put it through effects the same as a magnetic pick up.  On the top photo you can see I used one of these wired to a disc under the brige inside the box - it helps to control it so the piezo only feedsback at the highest volume.

 

Good luck with a solution,

David

PS any chance of a photo of the cigar box guitar?

[Sanddraggin]

I lined mine with tinfoil. Worked wonders

[Tom Caneschi aka TC]

Thanks to all for the ideas !!!