Just for a giggle, I decided to complete my latest build with a mini-amp built-into the guitar body. Anybody else try this? I used a Future Kit FK672 because it is small and comes with a microphone and 2" speaker.
Turns out that the electret microphone is way too hot and causes too much feedback, so I switched to a piezo. Of course feedback is still a problem. But I found that I could greatly increase signal to feedback by insulating the speaker from the grill and the grill from the cigar box using some of that 1/8" thick spongy double-sided tape. Now it works pretty good, with only a touch of feed back at the top end. Just pick it up and start twanging away.
I also added a switch in series with the battery to turn it off, and a 1/4" jack in parallel with the piezo so I can plug it into my amp if I want.
Replies
Nice job,
I would like to try this with a Honeytone.
Hi Mark,
Thank you for the interest.
The preamp on the top one is a takamine I picked up off ebay and the miniamp is a 3W kit from Maplins (UK)http://www.maplin.co.uk/module.aspx?moduleno=2904. It works well with the magnetic pickups but the piezos like to feedback if you crank up the volume too much.
The middle guitar is a kemo 3.5W universal amplifier module http://www.maplin.co.uk/Module.aspx?ModuleNo=37734
the easy way to add an amplifier
The bottom guitar is the same preamp kit as the top one. The piezo is a great find off ebay from China/Hong Kong listed as a "passive Preamp" - in reality it is a prewired kit that has a piezo undersaddle rod, passive volume and a passive tone that actually affects the sound of the piezo and an output jack socket. I rate these highly - I have recently just added one to a classical guitar and the piezo picks up so little extra noise and gives zero hiss unlike some active preamps. Also it can tolerate effects at a much higher level before you get feedback. I posted a few pictures previously http://www.cigarboxnation.com/group/cbgwiringelectronics/forum/topi...
Regards,
David
Very good sdtuff David.
It looks like a good idea to mount the speaker to the back of the box. If it could "float" on a spring or bit of foam it would isolate it from the guitar body even more.
It looks like you are using a preamp with some EQ controls going into a mini-amp? Yes? What brands/models are these?
I used a small decorative brass hasp with pivoting hook to close the box so I could get in and change the battery or tinker.
David Lloyd said:
Very slick! Love the one with the regular acoustic soundhole
Norm
David Lloyd said:
Hi Mark,
I have done it a few times - seems a shame not to use up some of the space in the box :0)
Sticking the speaker to the back of the box seems to make the piezo feedback less. Also due to the size of the speaker and 9v battery supply I decided that it was mainly for the player's benefit so stuck the last one on the side of the box so the player gets the most volume.
I tend to screw down the box lid so to make changing the battery easier add a battery box - cheapest ones I have found are from http://stores.ebay.co.uk/CharliesMusicShop search for "Dunlop battery box" the direct link is here http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=1604957063... until it is relisted.
Regards,
David
I would like to try this with a Zinky Lil smokey amp, after all he's my freind from Flagstaff.
mojo... self-contained and totally portable