Yamaha is big on that. There's also "clamp-on to the outside" devices which take the guitar's pickup signal, add effects - and push it back into the body. You can even buy your own DIY kit on ebay these days; pickup, battery powered effects, amplifier and transducer to excite the guitar body.
While these things maybe amplify the guitar some, they mostly make the body radiate reverb and echo-delay sounds, so you can get that effect without an outboard amplifier. What Joe is doing is making a monolithic guitar amplifier combo, primarily intended to amplify an acoustic guitar's sound. Of course all the standard effects, harmonica, vocals, drum machine etc could be mixed in with the guitar sound.
I imagine a busker could take it "down in the toilet and try to make it pay" and carry just one case - the guitar - instead of guitar case in one hand, amp in the other. Another aspect of the design is that you can point it at someone - like a megaphone - who you want to hear what you have to "say". A sonic weapon of sorts; well, maybe the electric guitar version -
ChinaChipAmp TPA3110 \ 3116 \ 3118 has dimensions of 40x50mm with a power of 15-60-100W. Can be powered by battery for screwdriver/bike. A 4" speaker has low efficiency. It is better to use four of these speakers in a lightweight foam or corrugated box.
It's beautiful but is the solid (err, hollow) wood stable over time?
There's a reason wood is laminated into plywood and similar and it isn't just cost.
There's a reason wood is laminated into plywood and similar and it isn't just cost.
Yes, like the tonewood amp, nice product. It gives you great tone options, from what I can tell, but not much more power/volume.
I think that would produce a lot of feedback. It would be an interesting experiment to see if I could control the feedback and manage sustain. It would kind of work like the Sustaniac electric pickup. https://www.sustainiac.com/st-pro.htm#overview
w/curiosity > ( a busker is a person who plays guitar) .... sometimes on street.... or subways. > How 'heavy ' is your guitar? > i LIKE 9 volt batteries . > NEXT,
Feedback is eliminated with a 1/2" thick chamber divider between speakers and standard chamber and pickups. Testing says this will work, but I still need to test the real thing, close.
The guitar weighs easily as much as an old Gibson Les Paul, probably more. Big sound, big guitar. 😎
The guitar weighs easily as much as an old Gibson Les Paul, probably more. Big sound, big guitar. 😎
Hi Joe,
I love the creativity of your project. Would it be possible to retro fit these panels into an existing body?
How’s progress going on the amplifier?
I love the creativity of your project. Would it be possible to retro fit these panels into an existing body?
How’s progress going on the amplifier?
Hello BF- fitting the folded horns into an existing body has been mentioned before, and yes it might be possible, but getting two five foot long folded horns into an existing body has major real estate problems. These horns follow the 1/4 wavelength rule (at 78 Hz low E string), which is a sixteen foot long wavelength. They have 1/4" thick walls of solid wood, and have other design calculations that have been considered. The sound and data have very encouraging results, downsizing would likely not go well on the audio side, but would need to be measured, and listened to of course. I have an open mind about this, but I did test shorter horns in a crude prototype, just did not have the power, or tone (especially low end).
For the amp, I am trying to use an existing acoustic guitar amp, pull out the guts and mount internally, off the shelf. So far results are encouraging, but an external amp is an option.
Any info you might have about a custom class D amp would be greatly appreciated. Thanks much for your input!
For the amp, I am trying to use an existing acoustic guitar amp, pull out the guts and mount internally, off the shelf. So far results are encouraging, but an external amp is an option.
Any info you might have about a custom class D amp would be greatly appreciated. Thanks much for your input!
Great, understood.
I was wondering if you could make these panels a kit?
Well I’m sure you are in the correct place for advice on class-D. There are people here that sell their own boards.
Maybe you mentioned already, what kind of power do you need? There are many options, on eBay or AliExpress for low power class-D. Do you want something custom designed and built?
I was wondering if you could make these panels a kit?
Well I’m sure you are in the correct place for advice on class-D. There are people here that sell their own boards.
Maybe you mentioned already, what kind of power do you need? There are many options, on eBay or AliExpress for low power class-D. Do you want something custom designed and built?
A kit is a very interesting idea, not there yet but possible in the future. I am looking for at least 20 watts per channel, battery powered. More is better of course, more head room.
Many great existing amps out there of course, but I need something that is approx. 2" x 5" x 8" including battery pack, pots, connectors. I know, a stretch!
Do you build class D custom amp boards? See attachment and thanks!
Many great existing amps out there of course, but I need something that is approx. 2" x 5" x 8" including battery pack, pots, connectors. I know, a stretch!
Do you build class D custom amp boards? See attachment and thanks!
Where is the battery located, are there size constraints? What is the expectation on access to that battery and or recharging it. At those power levels I think it might drain quickly.
These are ball park figures, but to supply 20W continuous to a 4Ohm speaker, you need to draw about 2A from the battery (20W = I^2 x 4 Ohm). So a 2000mAh battery will last around an hour.
You will need some form of DC to DC conversion because you want to run the rails for the amp at higher voltage than the battery.
For music you do not need to supply max power all the time; it has a lower crest factor. So let’s say when you are really playing hard you draw 2A but others times much less. This will extend battery life more. It’s hard to estimate that.
What is the largest possible battery mAh given all your constraints?
If it was me (and it never is...) I'd like to use portable electric drill batteries. The ones for my Porter-Cable drill are Li-Ion @ 20V and 1.3 Ah. You can get them in 2 and 4 Ah capacities; they're fatter of course.
One would think quickly clipping on a new one, when needed, would be quite an advantage when busking on the street with that guitar. Just as it is in the context of a cordless electric drill.
I'd hate to have to design the housing, mechanical attachment, the electrical connector, the charging system, any safety and cell protection features all by myself, on top of the guitar and amplifier integration.
Of course, https://www.portercable.com/solutions/20v-max-system doesnt sell their stuff for general use; only for their own products... For a one-off prototype just to show the concept, one could buy the flashlight and adapt its fastener and connector onto the guitar - somehow.
You can buy power adaptors for popular drill batteries on Ebay.
Be sure to pick a power adaptor and not a battery holder without connections as they are used only for storage.
Be sure to pick a power adaptor and not a battery holder without connections as they are used only for storage.
Aaandddd there it is! WoW! https://www.ebay.com/itm/144565771314 Thanks so much for pointing this out. Only $10 too.
I like how it says "Dont touch the red and black wires together with the battery inserted" Heh Heh. Someone must've done that, to explicitly state what most of the 70 buyers so far would think of as obvious. Live and learn!
BF - my only need is a 5" x 8" x 2" amp with a battery that fits in my guitar. I am NOT an electronics guy, that is why I need you guys!
I know my strengths, and they have helped me big time, but more importantly, I know my weaknesses.
JJ - I love the swap out battery idea, just did it with my drill, great idea, can that work!? Why the hell not!
I know my strengths, and they have helped me big time, but more importantly, I know my weaknesses.
JJ - I love the swap out battery idea, just did it with my drill, great idea, can that work!? Why the hell not!
I reckon the best-suited amp for your application would be based on MA12070. The reasons being - first, it sounds good and second, its very economical of battery life. Its a stereo chip so will drive both of your drivers individually. Unfortunately there isn't a wide choice of amp boards using this chip - the one I'm suggesting is one of the cheapest but comes with features you don't need, like Bluetooth : https://www.aliexpress.com/item/100...!sea!HK!2609685283&curPageLogUid=eFkKbleK5Q6s
Thank you so much AB, appreciate your input! Attached shows the Roland AC33 I am using now. Plugged in with the full amp sounds great!
Shown is a second AC33 with guts ripped out, need all the pots and connections. I can fit it, with batteries, but it is ugly, and not a great fit, protrudes out the back of guitar, need better! Man this guitar sounds really great with the horns, drivers and amp, just need a smaller Class D to top it off! Keep the ideas coming and thank you. let's rock!
Shown is a second AC33 with guts ripped out, need all the pots and connections. I can fit it, with batteries, but it is ugly, and not a great fit, protrudes out the back of guitar, need better! Man this guitar sounds really great with the horns, drivers and amp, just need a smaller Class D to top it off! Keep the ideas coming and thank you. let's rock!
Hey Joe
I read over your docs. If you want a special design I suggest you write up a specification. You have some of it done but some more details need clarification on the electronics.
Stuff like,
I do not see where the pickup is located? Where do the pickup electronics go. You say pot(s)? What do they do? Where are they placed, output jacks, what types?
Decision on the battery? Is it to be internal, if so what connectors, how is it charged
If it’s to be removable, needs to be charged externally, battery specs etc
I am sure there is more ...
Look at the old diy audio project called wiener it’s a small class D type amp using a TI chip, I built a few of them, not sure if it’s the right solution for you but an example of what can be done.
I read over your docs. If you want a special design I suggest you write up a specification. You have some of it done but some more details need clarification on the electronics.
Stuff like,
I do not see where the pickup is located? Where do the pickup electronics go. You say pot(s)? What do they do? Where are they placed, output jacks, what types?
Decision on the battery? Is it to be internal, if so what connectors, how is it charged
If it’s to be removable, needs to be charged externally, battery specs etc
I am sure there is more ...
Look at the old diy audio project called wiener it’s a small class D type amp using a TI chip, I built a few of them, not sure if it’s the right solution for you but an example of what can be done.