Hello all - I am looking for an amp to install INSIDE my Acoustic Waveguide Guitar. The patent has been submitted but not granted yet. I do have another granted patent for this product titled Folded Horn Acoustic Guitar (Patent # 10,777,172). Check it out on Google Patents. I posted this a year ago on the Instruments and Amps forum, and have had excellent feedback, but I wrote a new patent based on testing, and changes being made. I am not trying to post the same info again, which focused on the guitar design, construction and audio requirements, but now need some info regarding the electronics. I cut the electronics out of a Roland Acoustic Guitar Amp AC-33, and can fit inside my guitar, but just barely.
I would like to know if anybody is interested in building an amp and controls that are similar to this, but smaller if possible. I would purchase this to go into my DIY project. I have my own 3" full range speakers, 20 watts, 4 ohms, and the Roland is 15 watts per channel, 4 ohms. I am also using a Fishman piezo pickup/preamp to power the amp. The Roland AC-33 is battery powered, so this guitar can be played UNPLUGGED.
It is 20 dB louder (4X) than a standard acoustic guitar, and the internal waveguides (with horns on the end) are five feet long (two of them). This captures 1/4 wavelength of the lowest frequency on a guitar (approx. 85 Hz). The lows are incredible, a great acoustic guitar sound. Add a little gain and reverb, and this thing sounds like an old maple Gibson hollow body electric, maybe because the body is CNC machined from a solid piece of hard maple (6" x 18" x 24" before machining), and the waveguides are covered with 1/2" Baltic Birch. There is an upper chamber above this also, stand acoustic chamber. Maybe some people will add comments from the past thread (hope I am not double dipping). See attached, as Franklin said "our critics are our friends, for they show us our faults". Bring on the comments and thanks! Joe K
I would like to know if anybody is interested in building an amp and controls that are similar to this, but smaller if possible. I would purchase this to go into my DIY project. I have my own 3" full range speakers, 20 watts, 4 ohms, and the Roland is 15 watts per channel, 4 ohms. I am also using a Fishman piezo pickup/preamp to power the amp. The Roland AC-33 is battery powered, so this guitar can be played UNPLUGGED.
It is 20 dB louder (4X) than a standard acoustic guitar, and the internal waveguides (with horns on the end) are five feet long (two of them). This captures 1/4 wavelength of the lowest frequency on a guitar (approx. 85 Hz). The lows are incredible, a great acoustic guitar sound. Add a little gain and reverb, and this thing sounds like an old maple Gibson hollow body electric, maybe because the body is CNC machined from a solid piece of hard maple (6" x 18" x 24" before machining), and the waveguides are covered with 1/2" Baltic Birch. There is an upper chamber above this also, stand acoustic chamber. Maybe some people will add comments from the past thread (hope I am not double dipping). See attached, as Franklin said "our critics are our friends, for they show us our faults". Bring on the comments and thanks! Joe K
Unbelievable work. If you can find a class D amp board that sounds good in the guitar, it would be very small
and easy on the battery.
and easy on the battery.
Thank you so much rayma, I have much to learn about amplifiers, definitely not my specialty, that is why the diyAudio site is so great. I really like the sound of the old Fender Twin Reverb tube amps, but of course tubes will never fit. I know that class D amps are very efficient, so of course a good choice. I will keep researching and learning. Keep the comments coming and thanks! Joe
I haven’t used this so I can’t vouch for quality. https://www.guitarfetish.com/Onboard-25-Watt-Guitar-Amp-Drive-a-speaker-OR-Headphones_p_567.html
they also have onboard effects like chorus too.
There are a lot of kits for cigar box guitar amps, they might be too dirty for what you are looking for.
There is a cult following for the Ruby Amp. http://www.runoffgroove.com/ruby.html I have made these and they sound good for what they are, inexpensive little amps. They will run a 9V battery down in a weeks time.
they also have onboard effects like chorus too.
There are a lot of kits for cigar box guitar amps, they might be too dirty for what you are looking for.
There is a cult following for the Ruby Amp. http://www.runoffgroove.com/ruby.html I have made these and they sound good for what they are, inexpensive little amps. They will run a 9V battery down in a weeks time.
Thank you sir, I appreciate the links, may lead to something else. I need approx. 15 watts per channel to rock these guitar horns well, so these are just too small. The horns are each five feet long, so they really do the job tonally and sonically if given enough power from the drivers, which are 3" full range drivers, 20 watts output max each. BTW I have noted here before, if you use these in my guitar without the horns, not soo great. Seal up the horns 100% and wow! If you see anything more powerful in the amp community let me know and thanks!
https://www.ebay.com/itm/185618481702
These TDA8932 amplifiers are a dime a dozen all over ebay and I'd expect Alibaba, etc. Spec sheet says it'll drive 2, 4 Ohm speakers at 15W each or 1 at 30W. Nice wide range supply; 10 - 35V reduces the worry of exceeding 24.999V that'll blow up other chips with battery string fully charged. PWM switching frequency can go up to 500kHz, so if you could wedge it into the same compartment as the speaker drivers, maybe dont even need the output inductors for cost savings in a final product design. Distortion at and just below rated power is reasonable for a guitar amp.
Remember as I advised in the other thread, you still need to put something in front of it, between the pickup and power amp. That something will determine how it sounds and plays much more than the "final" power amp. For that chunk, there's probably dozens to choose from - anything from a commercially available units like https://www.ebay.com/itm/154244076213 or https://www.ebay.com/itm/155290727344 - yeah, a preamp with a touch screen control. Higher end stuff like from Baggs https://www.ebay.com/itm/266053224603 is much more spendy, but at least you know they thought about how it overdrives when they designed it. "The Session VTC’s “tape-like” saturation is voiced specifically for the acoustic guitar" mmmMMMM!
These TDA8932 amplifiers are a dime a dozen all over ebay and I'd expect Alibaba, etc. Spec sheet says it'll drive 2, 4 Ohm speakers at 15W each or 1 at 30W. Nice wide range supply; 10 - 35V reduces the worry of exceeding 24.999V that'll blow up other chips with battery string fully charged. PWM switching frequency can go up to 500kHz, so if you could wedge it into the same compartment as the speaker drivers, maybe dont even need the output inductors for cost savings in a final product design. Distortion at and just below rated power is reasonable for a guitar amp.
Remember as I advised in the other thread, you still need to put something in front of it, between the pickup and power amp. That something will determine how it sounds and plays much more than the "final" power amp. For that chunk, there's probably dozens to choose from - anything from a commercially available units like https://www.ebay.com/itm/154244076213 or https://www.ebay.com/itm/155290727344 - yeah, a preamp with a touch screen control. Higher end stuff like from Baggs https://www.ebay.com/itm/266053224603 is much more spendy, but at least you know they thought about how it overdrives when they designed it. "The Session VTC’s “tape-like” saturation is voiced specifically for the acoustic guitar" mmmMMMM!
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PE has these: https://www.parts-express.com/WONDO...o-Amplifier-Board-TPA3116-320-3342?quantity=1
You will need some kind of preamp with this one. I’ve had good luck with Wodom and Sure amps, your mileage may vary. The power ratings are overblown on a lot of these smaller amps, they’ll say it’s a 100W amp but really it’s 50W per channel into 4 or less ohms. So, really they are 25 Wpc or less Into standard 8 ohm speakers.
I also saw an amp that had microphone inputs, wouldn’t it be cool to put a harmonica through there? Maybe that’s too crazy and way off target for now?
Thank you JJ - I did buy a few of amps online, but I really want something that is plug and play, as soldering electronics is not my strong area. There are some that are pretty powerful, so I will check those out for sure. I also wonder about their sound quality at such a low price. Ripping the guts out of a real acoustic guitar amp is going well, just a smidge to large, very close.
Arthur - I play blues harp, so running a harmonica is not a crazy idea at all, I have wondered about it, will need to test for sure. The only problem for me is I like to play with the traditional cupped hands method, but I have also used the Neil Young method with a "harp holder", so that would work. It is an option for sure. Plus voice thru a mic in one channel while playing guitar in the other channel. I really need a third channel, more space required, oh no! 😎
Arthur - I play blues harp, so running a harmonica is not a crazy idea at all, I have wondered about it, will need to test for sure. The only problem for me is I like to play with the traditional cupped hands method, but I have also used the Neil Young method with a "harp holder", so that would work. It is an option for sure. Plus voice thru a mic in one channel while playing guitar in the other channel. I really need a third channel, more space required, oh no! 😎
I'm pretty sure nothing exists, that'll just happen to fit, sound good, be rechargable battery powered, etc. I've heard of a Crate "taxi", which is a small 15W single speaker battery powered guitar amp; perhaps gutted it'll all fit in there.
Zero issue for guitar sound reproduction. Even in HiFi, power amps are now the most transparent component, SQ having been worked out to well beyond acceptable / perceptible - even in the cheap stuff.
A guitar amp is a preamp + power amp. I just said the power amp isnt going to make a SQ difference in your application, so it's all in the preamp and how it behaves wrt the guitar pickup signal SQ wise. If I had the money, I'd be all over that Baggs preamp, (lots of acoustic guitars come with Baggs preamps) then find a suitable power amp. The one I quoted seems like a shoe-in for your 15W / speaker requirement of a self contained, battery powered system. Learn to solder then. There's got to be someone here in the Chicago area who could show you the basics.
OK thanks JJ - it sounds like a pretty great option then, if the sound quality will be there. I will buy some and do testing, learn a bit more about amps and assembly...really need the space!
Amazing! > (folded horns inside acoustic guitar).... w/3" 'full range speakers'. The first thing a guitar player would ask is ' what's it sound like'? ( w/out a nine volt battery. And> Is the neck straight? Does it intonate? easily. You married up 'idea' of 'folded horns'... from 'Hi-Fi'.... into an 'acoustic instrument'. I'm impressed and want to see what happens next. w/respect.
Thank you sir for your response, it sounds great and I can prove it! The neck is straight as an arrow. Check out the PDF with what I hope is good evidence. I have been working on this for years. The dB shows it to be about four times louder than a standard acoustic guitar, but even more importantly the tone is great, otherwise why do it? You can feel this powerful guitar rock your body when you play it, not kidding!
.... is idea to make it louder? > powerful guitar rock your body .? (forgive me> nylon or steel stringed guitar)? am unable to download PDF using this computer. If you have prototype available.... to be played... Let me know how it goes. (It's a good idea....
Hmmm...we haven't seen them, can U show us ? Because...
I remember that in the center of my town there was a busker playing electric guitar, and he had a tiny amp-head ( ?) from the back I could see the speaker with a huge magnet ( the speaker was 4") so this leads to a precise type of LS.
midrange, big-magnet > high efficiency in the passband.
Not a 3" fullrange 20W.
Thank you vglaso, yes the idea is to make an acoustic guitar louder, but also it is very important to maintain the beautiful tone, hence the horns that are needed, not just stick a speaker in the body and hope for the best.
Thank you Pico. I have seen the speakers in electric guitars, pretty cool, but since mine is an acoustic guitar, not direct competition, and the patent specifically states this is for an acoustic guitar.
Thank you avtech, I will finish this and bring it to market in some way, or sell it to somebody who does that, so far looking very good, stay tuned and thanks! Joe
Thank you Pico. I have seen the speakers in electric guitars, pretty cool, but since mine is an acoustic guitar, not direct competition, and the patent specifically states this is for an acoustic guitar.
Thank you avtech, I will finish this and bring it to market in some way, or sell it to somebody who does that, so far looking very good, stay tuned and thanks! Joe
w/respect> I can envision? an acoustic guitar ... w/ horn loading... done on a CNC machine? ...from 'what type of wood'? > with a nine volt battery. (or two) 'All inclusive'. 'louder is not always better'. > And, am curious> how do you wrap the horns... inside the 'body'... of 'start with a nylon-string flamenco ? How thick is the acoustic guitar going to be? > (and what does it weigh?) I would like to see/play a simple prototype.