9v pedal w/ 12v supply, Safe?

Discussion in 'Effects, Pedals, Strings & Things' started by ducmike, Apr 24, 2008.

  1. ducmike

    ducmike Silver Supporting Member

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    I'm looking for a new way to power my board. I have to Nova pedals, so I'm thinking the Trex 12v power supply. I noticed that some pedals have a 9-12v next to the power jack. I have the to Nova pedals, as well as a strobostomp, a hellbaby, and will be adding a new wah soon.

    Anyone ever try this? Or am I asking for trouble.
     
  2. mcknigs

    mcknigs Supporting Member

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    I've heard of some pedals that supposedly excel if you give them 18v rather than 9v. Some Fulltone pedals are like this. With other pedals I've read warnings about giving them any more than 9v. I think you would want to do some research on a pedal by pedal basis before plugging them into 12v.

    -Scott
     
  3. walterw

    walterw Gold Supporting Member

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    right, otherwise, you might let all the magic smoke out, then they won't work anymore.
     
  4. ducmike

    ducmike Silver Supporting Member

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    Thanks for the advice.

    After re-reading the Nova Power supply thread I decided to play it safe and picked up a PP2+ at GC yesterday. It seems to work great on the TC pedals with the L6 outputs switched to on. The strobo and X2 can run on 12v, but you never know what other pedals GAS will bring in, so 9v power is the safe bet.
     
  5. kp8

    kp8 Member

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    why would you even want to run the tuner at 12v?
     
  6. Lyle Caldwell

    Lyle Caldwell Member

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    If the pedal is digital, use only what the manufacturer calls for. If the circuit is analog, then there are two limiting factors.

    First, what voltage all the caps are rated for. Most people use 16v caps at a minimum, with 25v and higher caps being the most common. But some use 10v caps, and magic smoke is easily obtained. So, if a pedal has caps rated 25v or higher, and there is no internal voltage increase/split power going on (which can result in voltages much higher than what goes into the power jack), the pedal can be run at higher voltage.

    That is just a question of safe operation.

    The other factor is the designer's intent. Some pedals will work safely at a higher voltage but won't necessarily sound very good. This can be common with effects that rely on a certain bias range - trems and vibes are good examples. If the voltage goes up too much, the effect may be way too pronounced to be musically useful, even though the voltage is safe in terms of not damaging any components.

    All this boils down to "ask the manufacturer".
     
  7. ducmike

    ducmike Silver Supporting Member

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    I don't. But the TC Nova pedals should have 12v. But they do work fine at 9v with enough amps. So I'm sticking with the PP2.
     
  8. alltone

    alltone Member

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    I use EFX sometimes in a studio environment where quiet is a good thing..I have , for many years used a 12 volt (@ 3 amp hours) Gel Cell re-chargable battery to power all kinds of pedals.I have never had a problem smoking pedals,not to say that it could not happen with a cheapie pedal. The 12 volt battery is dead quiet( especially good for wah pedals) and powers, in my case...7 pedals for an average of 25-30 hours before I recharge.The gell cells are relatively inexpensive and will last for years, a little bulky , about the size and weight of 1 1/2 pounds of butter!!:banana
    Caution::FM Be VERY careful that you observe correct polarity and that none of your pedals are using a Positive Ground!!:horse
     
  9. alltone

    alltone Member

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    :agree:AOK
     
  10. WailinGuy

    WailinGuy Member

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    Good post!

    The only thing I would add is that caps rated at 10 volts are pretty rare in pedals. In general, the minimum cap voltage rating you'll find inside a pedal is 16 or 25 volts. Even for running a pedal at only 9 volts, they would not be a good choice, since they don't leave much margin of error. Also, fresh batteries typically put out more than exactly 9 volts. New alkalines can measure around 9.6 volts, and new "heavy duty" (zinc chloride) batteries can sometimes measure slightly over 10 volts.

    So my guess is that nearly any analog circuit pedal is going to work fine when powered at 12 volts. In many cases, they will perform better (in terms of headroom, bandwidth, etc. - which, in the world of electric guitar, do not necessarily translate to better tone, of course) since op-amps are usually spec'd for well over 9 volts (but still work well enough at lower voltages).

    But checking with the manufacturer first is always a good idea.
     
  11. Stratso

    Stratso Member

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    If a 9V pedal fails from being powered at 12V, then it's a poorly designed pedal and they're probably failing all over the place.
     
  12. Lyle Caldwell

    Lyle Caldwell Member

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    Some of my pedals take 9vdc in, but internally change this to 18vdc. These pedals will not function if you put in 12-18vdc. They won't die, they will just shut off until the incoming voltage is back down to 9vdc.
     
  13. Julia343

    Julia343 Member

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    I'll also mention this... One jam session I forgot to bring a wall wart. No 9v available. guy had a 12 v. Plugged it in. the Diode on my pedal never turned off the entire time it was plugged in. I won't do that again. Stick with the recommendations of the manufacturer in voltage/amps.
     
  14. lonestargtr

    lonestargtr Silver Supporting Member

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    I, too, am trying to configure a pedalboard using two Nova pedals (mod and delay) along with other stomp boxes (including a strobo-stomp, Boss limiter with ACA voltage, Cochrane Timmy and a Klon). I'm not really keen on experimenting running the Klon at 12V because it's such an expensive pedal that I'd be foolish to risk it. I'm also not very keen to call Mr. Finnegan because I'm pretty sure he'd tell me not to.

    All that being said, is anyone out there really using the PP2+ to power two Nova pedals? I'm just curious because the literature says that the Novas want 12VDC with a minimum of 300mA and the Line 6 outputs on the PP2+ only put out 12VDC at 250mA. I've read a lot about Novas adding noise or not working properly with insufficient amperage. Just wondering how well it works since I already own a PP2+. All else fails, I'll use the tc wall warts, but just trying to simplify the connections.

    thanks,
    Mike
     
  15. amp_surgeon

    amp_surgeon Member

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    A lot of pedals are clones of, or at least variations of classic designs that originally ran only on a 9V battery. The only reason overvoltage protection would be required in a modern version of those circuits is because a DC adapter socket has been added.

    The only way to add overvoltage protection is to insert the protection circuit between the original pedal circuit and the power source. The simplest protection circuit would consist of a zener diode and a current limiting resistor. Anything more complex, like a 9V regulator IC, is going to need at least a couple of volts more than 9V coming in before it will be able to deliver 9V going out, which means it wouldn't be able to run on a 9V supply. That current limiting resistor is going to drop some voltage, even when the normal 9 volts is coming in. The engineer will usually choose a resistor that only drops half a volt or less under normal current conditions so that a 9.6V alkaline battery will deliver close to 9V, which is what the old carbon batteries delivered.

    A circuit like that WILL be able to handle 12V coming in, but the resistor might begin to warm up. Run it this way for too long, and you might cook the resistor.

    Some pedal circuits are safe to operate at a few volts above 9V, and may just have a regular diode instead of a zener, combined with the current limiting resistor. This will protect the pedal in case somebody "accidentally" plugs in a reverse polarity supply for a short period of time. However, do something stupid like plugging in a 24V adapter of any polarity and you're going to fry that resistor.

    There are a LOT of pedals that have one of the two circuits described above. They are meant to protect the pedal in case you briefly use the wrong type of power supply. They are NOT meant to give you flexibility in what voltage supply you choose to use.

    Bear in mind that more robust overvoltage protection could have been provided if all pedals were designed to run internally on 9V, but use a 12V external supply. This isn't the case, as we've all gotten used to using supplies that have the same rated voltage as the batteries.

    Follow the manufacturers guidelines, and use a supply with the rated voltage and minimum current they specify.

    lonestargtr - I'd just use the TC wall warts, and not take any chances blowing out your PP2+.
     
  16. lonestargtr

    lonestargtr Silver Supporting Member

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    thanks. that's what I was thinking. 2 wall warts are going to be smaller and cheaper than getting the TRex Fuel Tank Juicy Lucy for those two pedals and I should have room under my pedalboard. It's only a matter of time until Voodoo Lab comes out with a Pedal Power "Nouveau" that will power them all safely. They've been pretty good about updating to accommodate the Boss Giga and Line 6 series stuff.
     

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