Power Supply For Active Pickups

[Juntunen Guitars]

For my next build I am planning on using active pickups but don't want to keep buying batteries so I thought "What if I could make a stompbox that would work as an external power supply that turns 120v to 9v ?" Obviously I would have to add an extra jack which is no big deal to me since I will be making a special cord for this if it works.

My only questions is if anyone out there thinks this is fiesable even and if I should make a resistor array or just use one resistor? I will be designing a circuit tomorow and will post it here.

[Juntunen Guitars]

Actually would this even work since a regular house outlet is AC current and a 9v battery is DC current?

[KeithHowell]

Buy a small power supply they cost around $10. Will be much safer and less work and probably cheaper than building your own.

From your question it doesn't seem to me you know the basics of building a power supply and messing with mains power can kill you!!!!!!

Keith

[borge]

You don't need another jack, you could send 9vdc up a trs cable.

But... theres no good reason to do phantom power as modern, low noise preamp designs have very low current needs and the typical battery life of 500-1500 hours is usually less trouble than the work involved and the result is a guitar that's useless without it's supply, rechargeable batteries are a better idea...

[Paul Marossy]

You don't need another jack, you could send 9vdc up a trs cable.

But... theres no good reason to do phantom power as modern, low noise preamp designs have very low current needs and the typical battery life of 500-1500 hours is usually less trouble than the work involved and the result is a guitar that's useless without it's supply, rechargeable batteries are a better idea...

I agree. Not worth the hassle.

[Juntunen Guitars]

Buy a small power supply they cost around $10. Will be much safer and less work and probably cheaper than building your own.

From your question it doesn't seem to me you know the basics of building a power supply and messing with mains power can kill you!!!!!!

Keith

I like to do things myself and I don't know that much about making power supplies. I know how to design circuits but have never looked at power supplies before. I suppose I could use rechargables I don't typically use them though because they begin to loose their charge after recharging them a few times.

[Akula]

Phantom power would work, using a TRS cable. Or rechargeable batteries. But if you havnt much experience in making mains power supplies, its probably better to either ask in an electricians forum, or buy one.

[Reinhold]

Or just use regular batteries, they really don't run out that often as long as you unplug the cable from the jack, it seems like your going to be going through an awful lot fix a simple thing that doesn't necessarily need fixing.

[Juntunen Guitars]

Or just use regular batteries, they really don't run out that often as long as you unplug the cable from the jack, it seems like your going to be going through an awful lot fix a simple thing that doesn't necessarily need fixing.

But when they start to drain doesn't the signal weaken? I have never owned active pickups I prefer Passive but would like to try Actives.

[Tim37]

unless you forget to unplug your guitar for a week the batties last a good while. but if you want just buy a power supply made for stomp boxes from what they advertise they have better regulation and more filtering than your standard wall wart.

any way if you really want to do it your self its not too hard all you need is a 13:1 transformer a rectifier and a filter and bam you have a power supply but thats a lot of work for something that cost less than 20 bucks.

[Samba Pa Ti]

i agree with the posts about buying a power supply, but the stompbox idea is quite good (even if batterys do last ages). sending power to the pickups whilst getting the signal from one cable would be nice, just need a cable with 4 pins which could be done with XLR4, using an xlr cable and putting an xlr socket into the guitar is the only drawback.

[borge]

Or just use regular batteries, they really don't run out that often as long as you unplug the cable from the jack, it seems like your going to be going through an awful lot fix a simple thing that doesn't necessarily need fixing.

But when they start to drain doesn't the signal weaken?

No. Internal preamps circuits are designed to be run on batteries, there are thousands of well designed active preamps out there running just fine for years on batteries...you are trying to solve a problem that doesn't exist.

i agree with the posts about buying a power supply, but the stompbox idea is quite good (even if batterys do last ages). sending power to the pickups whilst getting the signal from one cable would be nice, just need a cable with 4 pins which could be done with XLR4, using an xlr cable and putting an xlr socket into the guitar is the only drawback.

Like akula and I said, a trs jack will do it, not sure why you'd need 4 conductors...

Hell, you could even do it with a mono jack and DC blocking caps, maybe adjust the preamp to make up for the low end cut.

[Paul Marossy]

Or just use regular batteries, they really don't run out that often as long as you unplug the cable from the jack, it seems like your going to be going through an awful lot fix a simple thing that doesn't necessarily need fixing.

But when they start to drain doesn't the signal weaken?

No. Internal preamps circuits are designed to be run on batteries, there are thousands of well designed active preamps out there running just fine for years on batteries...you are trying to solve a problem that doesn't exist.

I agree. My Parker Mojo Nitelfy can go up to four or five months before the battery needs to be replaced. I'm sure EMG pickups are similar.

Is it that big a deal to open a little battery box on your guitar and quickly/easily replace the battery? If you put it in a stompbox, you'll have to remove four screws just to get to the battery. And if you don't have a screwdriver readily available, it will waste more time trying to track one down. Could be a real hassle if you are at a gig and everyone is already running behind.

Besides, what if you lose or forget your little box that powers your guitar? You are a dead in the water at that point because it ain't in your guitar.

[ansil]

emg 81's and most other emg's use approx 80 micro amps. or .08ma. now if you use one of the 10v lithium style batts that are rated at 1A approx again as they vary. you are looking at 1000ma/.08ma =12500hrs /24 is 520.83 days.

however if you wish to power it from an external source. a well regulated 9v power supply sent down the standard guitar cable apply a capacitor in your guitar to keep dc off your pots.

simple as that. http://www.till.com/articles/PreampCable/ some great inspiration

i am utilizing something like this on my brian moore to power the piezo preamp in it now, as well as the strat i am rebuilding i got some great tips on relocating the strat jack from you guys so thanks on that as well

[psw]

There is a product called the x-batt as I recall...sends power through a stereo cable to the guitar sharing the ground with the -ve volts...building your own powersupply is not advisable and really, not economical compared to what you can buy in a proper regulated supply...plus, it is so unnecessary and inconvenient as people have pointed out.

A solution without an actual problem...now a power hungry sustainer or onboard digital effects, maybe...but in reality batteries tend to last at least a year!

Something that might be of interest that I read recently from an old Adrian Legg modifying nook that is pretty clever...

Install a mercury switch into the guitar as well as the jack switch to disconnect power...this sense the physical position of the guitar and can be set up so that the power is turned off when the neck is upright...so, put your guitar on the stand and the power is off and your guitar is silent, till you pick it up and put it into a playing position.

And yes, I suppose you could make a pretty stupid "kill switch" with it

[westhemann]

I change out batteries about once a year or sometimes longer...just get into the habit of unplugging the jack after use.I do it even with my passives now.