Rechargeable 9v Supply

[AndrewCE]

Does anybody know of a 9v power supply that basically acts in this way: you put it in your guitar or pedal, and it acts as a battery supplying 9vDC. When you plug in a 9v adapter, the adapter powers the electronics AND recharges the battery. Then if you need to unplug the adapter the battery is still inside.

Has anybody heard of this? I assume if it existed it would be implemented in many, many stompboxes and guitars.

[borge]

This would be easy enough to do you just need to add the charger circuit (a 9v battery charger is not simply a 9vdc supply) put in a 9v rechargeable battery and rewire the jack to charge the battery.

IMO its not a large enough improvement over conventional rechargeable use to warrant doing. Of course its the perfect solution for those too lazy to take the battery out and put it in a charger

Just get a proper power supply and be done with batteries altogether, saves energy and money in the long run and (for the greenies out there) does away with the environmental implications of batteries.

Edited June 17, 2009 by borge

[AndrewCE]

This would be easy enough to do you just need to add the charger circuit (a 9v battery charger is not simply a 9vdc supply) put in a 9v rechargeable battery and rewire the jack to charge the battery.

IMO its not a large enough improvement over conventional rechargeable use to warrant doing. Of course its the perfect solution for those too lazy to take the battery out and put it in a charger

Just get a proper power supply and be done with batteries altogether, saves energy and money in the long run and (for the greenies out there) does away with the environmental implications of batteries.

i must just be one of those lazy people. actually i have more of a problem with HAVING a charger than USING it. if I could do with no charger, just a 9v supply, that would be awesome. one less thing to worry about losing.

[borge]

But where would it even be useful?

Obviously where ever you're using your pedals you're using an amp so mains power is present to plug you adapter into.

The only situations I can think of are whilst busking with a battery powered amp or when your power circuit is so close to capacity plugging in your adapter would trip the breaker

[AndrewCE]

But where would it even be useful?

Obviously where ever you're using your pedals you're using an amp so mains power is present to plug you adapter into.

The only situations I can think of are whilst busking with a battery powered amp or when your power circuit is so close to capacity plugging in your adapter would trip the breaker

well as a college student i would like to be able to listen thru headphones so as to not piss off my rommate, and then if i want to move away from my pedalboard i would like to attach the unit to my guitar strap (with the unit now on battery power) and make the amp more portable.

[borge]

I'm confused...

well as a college student i would like to be able to listen thru headphones so as to not piss off my rommate, and then if i want to move away from my pedalboard

why isn't your lead dictating your max pedalboard-guitar distance?

i would like to attach the unit to my guitar strap (with the unit now on battery power) and make the amp more portable.

what 'unit'? you mean a stompbox? how does that make your amp more portable? is your amp battery powered?

I use a tascam CD GT2 for silent practice, all i need is guitar>lead>GT2>headphones and I get multiple guitar &vox. effects, a cd player with tempo, pitch & key adjustment and an infinite looper and a plethora of other awesome things all in a small battery (i use rechargables ) powered package, I use it on bus/car/plane trips or anywhere else I've got a few spare minutes to get some practice/transcribing in.

I could even attach it to my strap and walk around the block playing

a vox plug and play headphone amp and a mp3/cd player would be a cheap alternative.

[AndrewCE]

what 'unit'? you mean a stompbox? how does that make your amp more portable? is your amp battery powered?

i would normally have the headphone amp at the end of my pedalboard. then, i would unplug it, thus switching into battery-power mode, and velcro it to my guitar strap. at that point i would have no FX, just guitar -> patch cable -> headphone amp -> headphones. that's ultimate portability.

or, if i want, i can build the headphone amp INTO my guitar, add a headphone out jack, and only use the 9v power supply to recharge the internal battery w/o removal

[Donovan]

what 'unit'? you mean a stompbox? how does that make your amp more portable? is your amp battery powered?

i would normally have the headphone amp at the end of my pedalboard. then, i would unplug it, thus switching into battery-power mode, and velcro it to my guitar strap. at that point i would have no FX, just guitar -> patch cable -> headphone amp -> headphones. that's ultimate portability.

or, if i want, i can build the headphone amp INTO my guitar, add a headphone out jack, and only use the 9v power supply to recharge the internal battery w/o removal

I think it makes perfect sense to do this... plug in and charge when hanging out near an AC outlet, then go wireless when you feel like it. I actually think this would be a great option for guitars with active circuitry. You could have a setup withought having to add a removeable battery pocket. Instead of routing the big, ugly pocket, there'd just be the standard AC adapter input jack, which could be placed somewhere on the pickguard and remain very inconspicuous. When guitar is not in use, plug in and avoid having to remove pickguard screws, strings, etc., or replace batteries. We do it with cell phones, why not a guitar?

That being the case, it's not actually the power supply that is the point of interest. Any above 9V'ish AC adapter will do the trick, so long as it is as "quiet" as you need it to be. What you need/want is a 9'ish volt rechargeable battery and charging circuit. There are various schematics floating about on the web for different types of batteries. A google search for battery charging circuit would be a good starting point. I found many doing this, but not many that had the necessary switching that would be necessary as the logic to control the system automatically. I suspect if you search around enough, you will find exactly what you need.

[borge]

We do it with cell phones, why not a guitar?

Because most active guitars last thousands of hours which equates to years per battery for most people?

But if you're doing something like the link below its a very cool idea.

i would normally have the headphone amp at the end of my pedalboard. then, i would unplug it, thus switching into battery-power mode, and velcro it to my guitar strap. at that point i would have no FX, just guitar -> patch cable -> headphone amp -> headphones. that's ultimate portability.

Thats exactly what the vox plug and play is except no need for the patch cable.

or, if i want, i can build the headphone amp INTO my guitar, add a headphone out jack, and only use the 9v power supply to recharge the internal battery w/o removal

Check this out:

http://projectguitar.ibforums.com/index.ph...travel%20guitar

Edited June 21, 2009 by borge

[Donovan]

We do it with cell phones, why not a guitar?

Because most active guitars last thousands of hours which equates to years per battery for most people?

But if you're doing something like the link below its a very cool idea.

Battery life is not the only consideration, but on what are you basing the generalizations that include hours "most" people play and the gear that "most" people play?

I'd agree to maybe modify that to "some of the longer-lasting systems" and "casual players".

For example a system with EMG 81/85 can be expected to last about 1500 hrs (3000 per pickup).

However, some single coil EMG's,like the SV, rate battery life down to about 400 hrs for a 3-pickup set.

My Ghost piezo system is spec's at 500 hrs. I play somewhere in the vicinity of 2-2.5 hours per day (alone) and another 5 with band, adds up to about 7 months per battery. I'd rather not have an ugly battery compartment route on my strat, so I have to unscrew my pickguard to change the battery.

Sustainiac systems are far less, rated for 15-40 hours.

Folks on this forum have stated their DIY sustainer systems last a few hours at best.

Let's also not forget that as battery life degrades, amplifier headroom degrades as well and signal quality/intensity degrades.

The advantage of a mod like an internal charger means for DIY, you do not have to route an ugly hole for the battery compartment, and instead foregoing this through susbstitution with a tiny jack. Very stealth idea for those wishing to maintain the aesthetics of original, passive design. As well, we take the guesswork out of remaining battery life. I'd rather plug it in the night before a show and feel confident in the charge than end up with a dead guitar half way through.

One might say, "well if I only need to change the battery once per year, why not just place it under the pickguard?" Sure, but every time we remove those pickguard screws, there is a little less strength in the holes than previous and we disturb the wiring,which is not designed to be disturbed over and over again without expecting failures at their terminations sooner or later. So, therein is another advantage.