Hello all,
I'm currently working on an onboard rechargeable power supply for electric guitar/bass that would replace the standard 9V batteries, wondering whether there would actually be a significant demand for this kind of third-party unit.
Specs are as follows:
* Selectable 9V or 18V output.
* Low-noise.
* Rechargeable via a standard micro-USB charger.
* LiPo or LiFePo4 battery versions.
What is the minimum battery life (in hours) between recharges that you think would be acceptable?
LiFePo4 batteries are inherently safer than traditional LiPo (li-ion) batteries and have longer overall life, but are chunkier/heavier for a given capacity. Which of the two would you choose?
I'm currently working on an onboard rechargeable power supply for electric guitar/bass that would replace the standard 9V batteries, wondering whether there would actually be a significant demand for this kind of third-party unit.
Specs are as follows:
* Selectable 9V or 18V output.
* Low-noise.
* Rechargeable via a standard micro-USB charger.
* LiPo or LiFePo4 battery versions.
What is the minimum battery life (in hours) between recharges that you think would be acceptable?
LiFePo4 batteries are inherently safer than traditional LiPo (li-ion) batteries and have longer overall life, but are chunkier/heavier for a given capacity. Which of the two would you choose?
Speaking only for myself, I put about 5 - 7 hours a week of playing time on each of my active basses and electro-acoustic guitars. I find that a new 9 V alkaline battery lasts me for months, so I have little incentive to switch to a lithium-based rechargeable type.
A few commercial guitars and guitar products use exactly the approach you're discussing, all the way down to USB charging. The Fishman Fluence product line includes some:
For me, LiPo packs would be completely unacceptable. Imagine if a $3500 guitar is destroyed by a $25 LiPo pack bursting into flames? This is a much worse financial nightmare than those experienced by former owners of, among others, incendiary Sony and Samsung phones.
IMO there is also one other distinct downside to a permanently installed-in-the-guitar rechargable battery pack: if you forget to charge it, and arrive at a gig with the battery dead, you cannot just pop in a few new AA cells and be up and running in seconds. Instead, you'll have to wait for 30 minutes to an hour for the lithium pack to recharge...while your audience boos, catcalls, and walks out. 😱
It would be interesting to try to obtain sales figures for the Fishman products; that might give you an idea what sort of market exists for the product.
-Gnobuddy
A few commercial guitars and guitar products use exactly the approach you're discussing, all the way down to USB charging. The Fishman Fluence product line includes some:
- For 'Strats: https://www.fishman.com/products/series/fluence/rechargeable-battery-pack-strat/
- For Les Pauls: https://www.fishman.com/products/series/fluence/les-paul-rechargeable-battery-pack/
- Universal: https://www.fishman.com/products/series/fluence/universal-rechargeable-battery-pack/
For me, LiPo packs would be completely unacceptable. Imagine if a $3500 guitar is destroyed by a $25 LiPo pack bursting into flames? This is a much worse financial nightmare than those experienced by former owners of, among others, incendiary Sony and Samsung phones.
IMO there is also one other distinct downside to a permanently installed-in-the-guitar rechargable battery pack: if you forget to charge it, and arrive at a gig with the battery dead, you cannot just pop in a few new AA cells and be up and running in seconds. Instead, you'll have to wait for 30 minutes to an hour for the lithium pack to recharge...while your audience boos, catcalls, and walks out. 😱
It would be interesting to try to obtain sales figures for the Fishman products; that might give you an idea what sort of market exists for the product.
-Gnobuddy
Agree^^^
Practicality and servicability are primary concerns. If I get to the gig and my battery is dead, I can grab one of the spares I carry and pop it in in seconds. I cannot recharge in seconds. What if someone loses my charger between gigs? I can buy a battery anywhere, chargers, not so much. And as someone who serviced this stuff for decades, I can tell you that any time ther is a charger jack on something, someone will connect just about any charger they can find, correct voltage or not.
And we can put rechargable batteries in the battery clips. Rather than wiring them in, we can recharge them elsewhere, and even have backups. Then if one fails, it is replaced in seconds.
Practicality and servicability are primary concerns. If I get to the gig and my battery is dead, I can grab one of the spares I carry and pop it in in seconds. I cannot recharge in seconds. What if someone loses my charger between gigs? I can buy a battery anywhere, chargers, not so much. And as someone who serviced this stuff for decades, I can tell you that any time ther is a charger jack on something, someone will connect just about any charger they can find, correct voltage or not.
And we can put rechargable batteries in the battery clips. Rather than wiring them in, we can recharge them elsewhere, and even have backups. Then if one fails, it is replaced in seconds.
Agree and add: active guitar electronics has very low consumption, so often it´s not that you empty the battery with your use, but internal self discharge kills it (albeit slowly) and *that* is what determines life.
So if I have an Alkaline battery with, say, 2 years shelf life and preamp eats very little (as happens in famous Music Man Stingray and similar Bass series, which use LM4250 programmable Op Amp) , practical battery life will be 2 years: its self discharge spec.
If I replace that Alkaline with a rechargeable pack which self discharges in 3 to 6 Months, I have actually REDUCED active life
In a nutshell: rechargeables are a good option with mid to high current loads, where the load itself discharges it quickly, but not when load is very low power , and then shelf life is the most important parameter.
Not sure many (or any) rechargeables match or surpass humble alkalines (of good quality of course) in raw shelf life.
So if I have an Alkaline battery with, say, 2 years shelf life and preamp eats very little (as happens in famous Music Man Stingray and similar Bass series, which use LM4250 programmable Op Amp) , practical battery life will be 2 years: its self discharge spec.
If I replace that Alkaline with a rechargeable pack which self discharges in 3 to 6 Months, I have actually REDUCED active life
In a nutshell: rechargeables are a good option with mid to high current loads, where the load itself discharges it quickly, but not when load is very low power , and then shelf life is the most important parameter.
Not sure many (or any) rechargeables match or surpass humble alkalines (of good quality of course) in raw shelf life.
Thanks all for your feedback.
I am aware of the Fishman product as the seemingly only available third-party solution on the market at the moment. Some newer Warwick basses come equipped with a rechargeable system and although I'm not sure, from the way it looks, it seems it's actually the Fishman system. So I suspect most of their sales may come from the OEM market.
I agree with most of your remarks, but I'm still wondering whether there may be a market for that and thus wondering what would make it more attractive to guitar or bass players.
I am aware of the Fishman product as the seemingly only available third-party solution on the market at the moment. Some newer Warwick basses come equipped with a rechargeable system and although I'm not sure, from the way it looks, it seems it's actually the Fishman system. So I suspect most of their sales may come from the OEM market.
I agree with most of your remarks, but I'm still wondering whether there may be a market for that and thus wondering what would make it more attractive to guitar or bass players.
Regarding safety, I agree and this is why I was considering LiFePo4 batteries instead of LiPo (although the Fishman product has a LiPo battery). LiFePo4 is much safer even when abused.
Regarding the "dead battery" case, I agree, although I have designed a "low batt condition" detection which makes an LED blink at least several hours before the battery would be dead, thus keeping the user informed in advance. In Warwick basses in which the rechargeable system is installed, they provide an additionnal connector to put a regular 9V battery instead in case your internal battery is dead, and you can exchange the two in like 2 minutes.
Shelf life of LiPo (and even better, LiFePo4) batteries is pretty good compared to alkaline batteries, so self-discharge is not really an issue with those. But of course, once you switch to a rechargeable solution, you have to make the charging as part of your routine, so that's an added constraint, although most people are used to that with their mobile phones already.
An added benefit is the ability to switch between 9V and 18V (at the flip of a switch) and the regulated output which insures a stable 9V or 18V up to the end of battery life, which is not quite the case with regular alkaline batteries.
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My idea was to power the guitar thru the guitar cord with the power coming from a box between guitar and amp. DC to the guitar, AC from the guitar. No special cord. If it fails, pop in a battery. No more batteries. So far just an idea, seems possible to isolate the DC from AC but I haven't tried to work out the details. The down side would be having to mod the guitar. If anyone knows this is a stupid idea please say.
Don't know about other guitars but my bass disconnects power when you pull the cord out so the guitar mod might not be that difficult.
powering remotely is simple/without any modificatgions to must guitars. just place a shorted battery and feed the ring of a stereo guitar plug with 9V vs sleeb, tip is signal vs sleeve. works on 99% of the guitars that use the stereo socket to turn on the electronics using a mono plug. only a few guitars ( i know a few yamahas that have a mechanically actuated switch upon insertion to turn on the electronics.) I built a DI box on 48V phantom power that also phantom powers the guitar on 9V.
Not a stupid idea at all. I had the same idea in the late 1980's, and used it to power a JFET preamp I built into a DIY electric guitar I made.
More recently, I found the same idea is used quite routinely with condenser microphones (phantom power supplied via the mic cable).
And it's also been done commercially with guitars. For example, I have a Takamine electro-acoustic guitar with their "Cool Tube" preamp. The electronics includes the capability to feed it power via a (stereo) guitar cable, pretty much as Basreflex described.
But 99.9% of guitars - and guitar amps - do not have any support for delivering power via the guitar cable. There is no industry standard, either, so even those guitars that include this capability only work with their own brand-specific preamp.
So, regrettably, I would say the chances of such a system ever actually catching on widely are somewhere between "Not in a million years!" and "Never!" 😀
-Gnobuddy
99% of guitars have their electronics switched on by shorting the ring of the stereo socket to ground upon insertion of a mono plug. so when you install a shorting battery you can suppply the guitar through that ring. only the amps are not adapted for that, I saw one swedish bass amp that had it built in.
There is such a solution: Zampower (french company, with seemingly no web page in English, sorry about that). The drawback is that you have to use stereo cables and you have to bring this box with you at all times. This is apparently providing the power supply through the additional conductor, so pretty simple.
Phantom powering (just like microphones) is another option, but rarely seen on guitars and this is why: phantom powering on an unbalanced signal such as the output of an electric guitar would sound like crap. You'd directly get your power supply noise on top of your guitar's sound. Phantom powering works best with balanced (differential) signals. To convert a guitar to a balanced output would require to add an onboard, phantom-powered balanced output stage and replace your jack socket with an XLR one (chunky) and use XLR cables (chunky as well). Not very practical in my opinion, although that would probably sound great and remove the need for a DI box.
Solutions with onboard batteries allow you to leave your instrument in a standard state output-wise and are more likely to be acceptable in my opinion.
Phantom powering (just like microphones) is another option, but rarely seen on guitars and this is why: phantom powering on an unbalanced signal such as the output of an electric guitar would sound like crap. You'd directly get your power supply noise on top of your guitar's sound. Phantom powering works best with balanced (differential) signals. To convert a guitar to a balanced output would require to add an onboard, phantom-powered balanced output stage and replace your jack socket with an XLR one (chunky) and use XLR cables (chunky as well). Not very practical in my opinion, although that would probably sound great and remove the need for a DI box.
Solutions with onboard batteries allow you to leave your instrument in a standard state output-wise and are more likely to be acceptable in my opinion.
> phantom powering on an unbalanced signal....
...would be "Simplex" powering.
> You'd directly get your power supply noise on top
So use very clean power. I did it with custom mikes back in the 1980s. About six dollars of passive parts, would be less today.
...would be "Simplex" powering.
> You'd directly get your power supply noise on top
So use very clean power. I did it with custom mikes back in the 1980s. About six dollars of passive parts, would be less today.
There are some electro-acoustic guitars with XLR outputs. As far as I know, there have also been some electric guitars equipped in this way, primarily intended for studio use.
De Armond introduced surprisingly modern single-ended electric guitar pickups in 1939, when electronics was still in its infancy, and balanced signals would never cross the mind of a guitarist / inventor.
Leo Fender blatantly copied De Amond's pickup design several years later, and also never considered balanced signals; if only he'd center-tapped his pickup windings, grounded the tap, and provided the two end signals, his pickups would not suffer as they do from electrical interference.
Microphone signals being much weaker (and more susceptible to interference), something had to be done, and balanced signals became standard.
And, while XLR connectors go hand in hand with phantom power for microphones, there is absolutely no reason why stereo (TRS, or Tip/ Ring/ Sleeve) 1/4" plugs and jacks shouldn't be used to provide phantom power in exactly the same way. The standard wiring for balanced signals using TRS plugs and jacks is to have balanced, antiphase audio signals on the tip and ring, while the sleeve is signal ground. You could add DC phantom power in exactly the same way it's done on XLR setups.
To me, feeding power up the guitar cable makes a lot more sense than sticking a battery (of any type) inside the guitar itself. With phantom power delivered via the cable, you have power to the guitar any time you actually need it (i.e. any time it's plugged in), and you don't have to worry about leaking battery chemicals inside the guitar, limited battery life, et cetera.
This thread may actually have motivated me to build a system to provide power via the cable to the two electro-acoustic guitars I use most. I know my Takamine will work according to the recipe Basreflex outlined a few posts ago. I will have to investigate my Yamaha a bit more to see if the same recipe works on it, too.
-Gnobuddy
De Armond introduced surprisingly modern single-ended electric guitar pickups in 1939, when electronics was still in its infancy, and balanced signals would never cross the mind of a guitarist / inventor.
Leo Fender blatantly copied De Amond's pickup design several years later, and also never considered balanced signals; if only he'd center-tapped his pickup windings, grounded the tap, and provided the two end signals, his pickups would not suffer as they do from electrical interference.
Microphone signals being much weaker (and more susceptible to interference), something had to be done, and balanced signals became standard.
And, while XLR connectors go hand in hand with phantom power for microphones, there is absolutely no reason why stereo (TRS, or Tip/ Ring/ Sleeve) 1/4" plugs and jacks shouldn't be used to provide phantom power in exactly the same way. The standard wiring for balanced signals using TRS plugs and jacks is to have balanced, antiphase audio signals on the tip and ring, while the sleeve is signal ground. You could add DC phantom power in exactly the same way it's done on XLR setups.
To me, feeding power up the guitar cable makes a lot more sense than sticking a battery (of any type) inside the guitar itself. With phantom power delivered via the cable, you have power to the guitar any time you actually need it (i.e. any time it's plugged in), and you don't have to worry about leaking battery chemicals inside the guitar, limited battery life, et cetera.
This thread may actually have motivated me to build a system to provide power via the cable to the two electro-acoustic guitars I use most. I know my Takamine will work according to the recipe Basreflex outlined a few posts ago. I will have to investigate my Yamaha a bit more to see if the same recipe works on it, too.
-Gnobuddy
Any chance of a schematic? The more I think about your description, the less I understand how it works.
The (-) end of the internal battery is connected to the ring, so if you apply an external positive voltage on that ring via the guitar cable, you should end up feeding current through the internal battery, and adding the external voltage to the internal one, which might fry the onboard preamp. And there appears to be no way to connect to the positive end of the internal battery, to supply external voltage there.
What am I missing? 😕
-Gnobuddy
gnobuddy,
the trick is to place a shorting battery in the guitar, so the - or ring of the jack becomes the positive terminal. it is just a block with the size of a battery and its termiances are shorted. i've built small pcb's with btgerry terminals soldered on it.
re yamaha: there is a simple way to check: insert a stereo plug in the guitar (battery placed) and measure the voltage between ring and sleeve. if there is voltage, you can do the phantom biasing through the ring. if you measure a negative voltage vs sleeve you have to do positive biasing, and the other way around. I have developed DI's using 48V XLR pantom powering that also provide the 9V guitar supply. it is only 65x18x24mm, inline with the cable. mostly use for studio or performers that use their mixer. no pedals or the like though..
the trick is to place a shorting battery in the guitar, so the - or ring of the jack becomes the positive terminal. it is just a block with the size of a battery and its termiances are shorted. i've built small pcb's with btgerry terminals soldered on it.
re yamaha: there is a simple way to check: insert a stereo plug in the guitar (battery placed) and measure the voltage between ring and sleeve. if there is voltage, you can do the phantom biasing through the ring. if you measure a negative voltage vs sleeve you have to do positive biasing, and the other way around. I have developed DI's using 48V XLR pantom powering that also provide the 9V guitar supply. it is only 65x18x24mm, inline with the cable. mostly use for studio or performers that use their mixer. no pedals or the like though..
Thanks all for your comments and insights.
A rechargeable solution for guitars and basses doesn't seem to fit real-life needs.
I've put this project on hold for the time being.
A rechargeable solution for guitars and basses doesn't seem to fit real-life needs.
I've put this project on hold for the time being.
I'm sorry your business idea might not pan out for you, but I think you made the right decision (financially speaking).
The existing solution - a 9V alkaline battery in the guitar - may be inelegant, but it is stone-simple, and entirely effective. And, with many months of battery life, battery changes are not enough of an inconvenience to motivate guitarists to look for a better alternative.
Now, if you can find an affordable way to take the harsh edge off piezo pickup sounds, you may have something. The Takamine Cool Tube preamp does this very effectively, but is very expensive, and fits only Takamine guitars.
I can't find out very much about how the Cool Tube preamp actually works. My ears say that it does take the harsh edge off the piezo sound, while my mind suspects the "tube" part is more likely to be good advertising than good engineering.
In any case, I wonder if a simple JFET couldn't be coaxed into doing what ever that 12AU7 supposedly does. (Apparently the 12AU7 is running on 6 volts, or maybe only 3 volts, and at a temperature supposedly only two degrees Fahrenheit above ambient temperature.)
I found this interesting tidbit of information (of unknown accuracy) online:
This sounds as though it might not be entirely hogwash - my interpretation of this extremely non-technical description is that, perhaps, the tube is fed only the high frequencies, and it's output (including small amounts of low-order, sweet-sounding harmonic distortion) mixed back in with the full piezo signal to sweeten the sound.
That snippet came from here: http://www.musiciansfriend.com/reso...Electric-Guitar-with-Cool-Tube-Preamp/m711715
Worth a mention: the same source also makes the extremely implausible claim that:
Uh-huh. Sure thing. Power drag. Yeah. 🙄
-Gnobuddy
The existing solution - a 9V alkaline battery in the guitar - may be inelegant, but it is stone-simple, and entirely effective. And, with many months of battery life, battery changes are not enough of an inconvenience to motivate guitarists to look for a better alternative.
Now, if you can find an affordable way to take the harsh edge off piezo pickup sounds, you may have something. The Takamine Cool Tube preamp does this very effectively, but is very expensive, and fits only Takamine guitars.
I can't find out very much about how the Cool Tube preamp actually works. My ears say that it does take the harsh edge off the piezo sound, while my mind suspects the "tube" part is more likely to be good advertising than good engineering.
In any case, I wonder if a simple JFET couldn't be coaxed into doing what ever that 12AU7 supposedly does. (Apparently the 12AU7 is running on 6 volts, or maybe only 3 volts, and at a temperature supposedly only two degrees Fahrenheit above ambient temperature.)
I found this interesting tidbit of information (of unknown accuracy) online:
This sounds as though it might not be entirely hogwash - my interpretation of this extremely non-technical description is that, perhaps, the tube is fed only the high frequencies, and it's output (including small amounts of low-order, sweet-sounding harmonic distortion) mixed back in with the full piezo signal to sweeten the sound.
That snippet came from here: http://www.musiciansfriend.com/reso...Electric-Guitar-with-Cool-Tube-Preamp/m711715
Worth a mention: the same source also makes the extremely implausible claim that:
Uh-huh. Sure thing. Power drag. Yeah. 🙄
-Gnobuddy
I suspect they don't just use the nice properties of the 12AU7 when it goes into saturation, which you could try to get close to with a JFET-based preamp. Tube-based amps/preamps also tend to have a variable frequency response that depends on dynamic parameters of the input signal (and also the current 'state' of the amp, temperature, power supply voltage...) Under-biased tubes probably show even worse and dynamically-changing frequency response, which in this case, may be a nice bonus.
But even under-biased, tubes are power hogs. 🙁
Anyway, the key here may very well be this dynamically-variable frequency response (which may not be that simple to emulate with solid-state circuits). 😉
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