Voltage question

[guitarSQUIRELL]

I have a digitech RP350 and I lost the 9Volt power supply to it. I have a 15V power adapter. Will it work or will it burn it up? The processor is rated at 9V @ 1.5A.


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[PFDarkside]

Re: Voltage question

No, don’t do it.

The RP350 is 9V AC, right? Get a replacement 9V AC adapter that supplies at least as much current as the pedal requires. (1.3A is what google images shows)

 

[Blille]

Voltage question

I have a digitech RP350 and I lost the 9Volt power supply to it. I have a 15V power adapter. Will it work or will it burn it up? The processor is rated at 9V @ 1.5A.


Sent from my iPhone using Tapatalk

Don’t. It will likely fry.

With some simple analog pedals you have more wiggle room but with I would not risk it with a digital processor.

 

[67Mopar]

Re: Voltage question

Depends on the charge pump... While there are some that can handle up to 18VDC, it is highly unlikely that your pedal has been fitted with a $20.00 chip. Many pre-2018 pedals use a MAXX1044 charge pump; that tops-out at 10VDC. More up to date pedals will be fitted with a ICL7660S; that can handle up to 12VDC. Anything over the maximum will let out the smoke. I was surprised to see that my new Bogner La Grange (awesome pedal btw) is fitted with the lower voltage MAXX1044 charge pump. I would never run it over 9VDC, but I like having the increased headroom. NEVER exceed the maximum standard operating voltage. This is also why I never buy used pedals. At least not until I've thoroughly tested them.

A note about adapters: Never trust wall wart adapters when it comes to your pedals. I tested an older 9VDC wall-wart yesterday that was putting out 11.3VDC! had I plugged this into my La Grange, I would have cooked it. I once cooked a KLON clone using a EH 9VDC adapter that was putting out over 10VDC. A simple enough repair, but had it been a real KLON... Always use a regulated power distribution block.

 

[devastone]

Re: Voltage question

That went OT, pretty sure the RP doesn't have a charge pump since it is an older digital modeler.

The answer to the OP is, since it is a digital modeler, don't use anything but what it is rated for.

67M, if a 10V PS blew your Klone, something else was wrong. You are measuring the voltages without a load, when you plug them in to a pedal, the load brings the voltage down, probably in the 9 - 10V range. The pedals should have regulating diodes if they are that sensitive, but most are built to handle a few extra volts.

FWIW, if a pedal is spec'd to run at 18V, it probably doesn't have a charge pump. The reason pedal makers put charge pumps in pedals is to raise the internal voltage from the standard 9V power.

 

[Rich_S]

Re: Voltage question

Devastone speaks truth, so I won't bother repeating it all.

 

[67Mopar]

Re: Voltage question

That went OT, pretty sure the RP doesn't have a charge pump since it is an older digital modeler.

The answer to the OP is, since it is a digital modeler, don't use anything but what it is rated for.

67M, if a 10V PS blew your Klone, something else was wrong. You are measuring the voltages without a load, when you plug them in to a pedal, the load brings the voltage down, probably in the 9 - 10V range. The pedals should have regulating diodes if they are that sensitive, but most are built to handle a few extra volts.

FWIW, if a pedal is spec'd to run at 18V, it probably doesn't have a charge pump. The reason pedal makers put charge pumps in pedals is to raise the internal voltage from the standard 9V power.

I was speaking in general, not specifically his situation. MAXX1044 charge pumps are well-known to fry above 10 volts line supply, so yes, the 10.8VDC was more than enough to fry the charge pump in my KLON clone. Try pushing 12 volts into a MAXX1044 pedal, and see what happens... Even if the zener isn't taken out, the charge pump will be. Some pedals (depending on the circuit) can survive the higher VDC, others will not. As a general rule, no device should be subjected to higher than specified input voltage - ever! Your comment on 18VDC pedals not using a charge pump... Charge pumps are not only used increase voltage, they are also used to decrease voltage. 18VDC input can used to lower current in high demand devices. This is done to decreasing heat. Since such pedals are internally regulated, your comment on lowering voltage via load is non sequitur. Line supply is never determined by load... You're confusing voltage with amperage. If a 9VDC pedal with a charge pump is causing a 1VDC drop in line supply, something is definitely wrong!

 

[PFDarkside]

Re: Voltage question

67Mopar, look at how the old unregulated Boss ACA adapters worked.

The best advice is to always follow the manufacturer’s recommendations. Most will explicitly state if they take a wider voltage range. Just because 9V DV Center Negative is the “standard”, it always pays to check.

 

[devastone]

Re: Voltage question

The OP was pretty specific, so your answer was off topic. But, YES, it is definitely best to always use the proper power supply.

FWIW, good design would protect sensitive components from slight variations in input voltage, meaning 10 - 12V for a 9V design, if someone plugs an 18V supply into a 9V pedal oh well. Even a new 9V battery can put be more than 9V. If a component can't handle more than 10V, probably a good idea to put a 9.6V Zener in parallel to clip the voltage off there.

Not arguing that a power supply killed your Klone, just saying it shouldn't have if it was designed properly.

And yes, when you plug a supply into a pedal, the pedal is basically a resistance so as it draws current, the voltage at the output of the power supply is slightly reduced.

And you got me on charge pumps, I haven't played with them, but not sure why you would want to use one to lower the voltage on a 9V pedal, that would kill the headroom. The current draw in pedals isn't enough for heat buildup to be an issue unless maybe it is a tube pedal, then there are lots of other things to consider anyway.

 

[67Mopar]

Re: Voltage question

FWIW, good design would protect sensitive components from slight variations in input voltage, meaning 10 - 12V for a 9V design, if someone plugs an 18V supply into a 9V pedal oh well. Even a new 9V battery can put be more than 9V. If a component can't handle more than 10V, probably a good idea to put a 9.6V Zener in parallel to clip the voltage off there.

You are right. The 9VDC power supply I used was reading 13.2VDC, not 11.3VDC. My bad! I plugged the power supply into a Ceriatone Centura, and it cooked charge pump in less than 5 seconds! I used the same power supply on my Bogner La Grange pedal (MAX1044), but it did not cook the charge pump? Must be the supporting circuitry, because the Centura pedal uses a ICL7660S charge pump that sports a max input of 12VDC. The La Grange charge pump maxes-out at 10VDC, yet it did not cook it. ???

I ordered 3 different charge pumps and Zener diodes from Mouser yesterday. I'll experiment with the Centura as soon as they arrive. The charge pump cooked, but the diode is AOK. In terms of diagnostics; I never took classes in controls, so my experience is limited.

 

[devastone]

Re: Voltage question

I can't answer specifics about what might have happened to your pedal, what kind of power supply were you using that put out 13V? Still wouldn't expect that to kill it, I"m thinking something else may have been going on with the pedal(?).

 

[Zombiwoof]

Re: Voltage question

I once measured the older Boss ACA adaptor I have and it put out a little over 13 volts when plugged into nothing. That's why those old Boss ACA powered pedals don't work right with the more modern PSA adaptor, which is regulated and puts out closer to 9 volts. The ACA pedals need 12 volts to work right, unless they are daisy-chained with other PSA Boss pedals or if they are modded to use the later Boss adaptor.
Al

 

[PFDarkside]

Re: Voltage question

I can't answer specifics about what might have happened to your pedal, what kind of power supply were you using that put out 13V? Still wouldn't expect that to kill it, I"m thinking something else may have been going on with the pedal(?).

There’s a thread on the Gear Page about Klones being killed by “high” voltages. Depending on the charge pump and voltage protection used, some can take barely over 9.6V and some can take a decent amount over 9V.

 

[Darg1911]

Re: Voltage question

The original Klons used a Max1044 and a 1N4742 zener so a lot of the Klones do as well. I think that IC can take a max of 10 volts. One can just use a TC1044S... (12V max) but I suppose the purists would balk at that.

For the record, "wall warts" aren't evil. If your device cant tolerate any overvoltage and you need/want a solid 9 volts (or whatever voltage) there are regulated wall warts readily available.

 

[devastone]

Re: Voltage question

I once measured the older Boss ACA adaptor I have and it put out a little over 13 volts when plugged into nothing. That's why those old Boss ACA powered pedals don't work right with the more modern PSA adaptor, which is regulated and puts out closer to 9 volts. The ACA pedals need 12 volts to work right, unless they are daisy-chained with other PSA Boss pedals or if they are modded to use the later Boss adaptor.
Al

http://stinkfoot.se/archives/1019

There’s a thread on the Gear Page about Klones being killed by “high” voltages. Depending on the charge pump and voltage protection used, some can take barely over 9.6V and some can take a decent amount over 9V.

Wonder if this is a problem with the real Klons too? FWIW, I would guess a lot of clone pedals (of all varieties) are built by guitarists from schematics found on the interwebs, they know enough about reading a schematic to be dangerous, but don't pay attention to the small details like, if the power supply goes over 10V it could blow this chip up, nor how to protect it from that. Just a guess, and in my younger days, even with an electronics degree, I would have probably overlooked stuff like that myself. Actually never paid that much attention to it, back when I was building pedals for a store in NC nobody eve thought about using anything but a 9V supply, although, even if the PS put out 13V, there wasn't anything that it would hurt anyway.

 

[67Mopar]

Re: Voltage question

I can't answer specifics about what might have happened to your pedal, what kind of power supply were you using that put out 13V? Still wouldn't expect that to kill it, I"m thinking something else may have been going on with the pedal(?).

It was a generic 9VDC wall-wart. I don't recall the brand, but it was non-regulated. It's in the trash, so I'd have to did through a ton of filth to get to it.

I figured it out! Being a non-regulated supply, the DC output from the wall-wart would have increased with wall voltage. This explains the 11.3VDC reading from the wall-wart. Orlando area output gets as high as 127VAC during the day. I use a Tenma Variac and bucking transformers to keep the output level in-check for most of my gear. I am certain that I plugged the wall-wart (no variac) into the KLON during peak hours. I powered the La Grange at around 2:00AM using the same non-regulated supply. Wall voltage at this time would have been approximately 120VAC; bringing the wall-wart output down to its 9VDC spec. I should have checked the output with my meter before plugging it into anything. Live and learn...

I don't use a gang-box from my bucking transformer. My Ampeg GVT15 is the only piece of gear that goes into that unit. I plugged the wall-wart directly into the wall socket (to power the KLON) without thinking. Big mistake! I should have plugged the Ampeg and wall-wart into a power strip, then plugged the power strip into the bucking transformer... Hopefully my mishap will keep others from making the same dumbass mistake.

 

[jeremy]

Re: Voltage question

ive never heard of people blowing up klons, but i guess if you blew up a $2000 pedal cause you cheaped out on the power supply i might keep that to myself

 

[Darg1911]

Re: Voltage question

It was a generic 9VDC wall-wart. I don't recall the brand, but it was non-regulated. It's in the trash, so I'd have to did through a ton of filth to get to it.

I figured it out! Being a non-regulated supply, the DC output from the wall-wart would have increased with wall voltage. This explains the 11.3VDC reading from the wall-wart. Orlando area output gets as high as 127VAC during the day. I use a Tenma Variac and bucking transformers to keep the output level in-check for most of my gear. I am certain that I plugged the wall-wart (no variac) into the KLON during peak hours. I powered the La Grange at around 2:00AM using the same non-regulated supply. Wall voltage at this time would have been approximately 120VAC; bringing the wall-wart output down to 9VDC. I should have checked the output with my meter before plugging it into anything. Live and learn...

A non regulated supply's voltage will drop compared to the no load voltage when loaded down with a pedal. But, most pedals draw so little current that the voltage will still be above the nominal voltage rating of the supply. And, if the supply is rated for, example, 9 volts dc and 1 amp, I dont think it will come all the way down to the 9 volts unless the load is at or near the full 1 amp rating of the supply. Good reason why the wall warts that are designed for pedals and made by reputable companies are regulated supplies.

 

[67Mopar]

Re: Voltage question

ive never heard of people blowing up klons, but i guess if you blew up a $2000 pedal cause you cheaped out on the power supply i might keep that to myself

It isn't a real KLON Centaur. It's a Ceriatone Centura. Sounds identical to the original KLON. I only paid $200.00 for it, but that's still a lot of money. Well, it is to me anyway.

 

[67Mopar]

Re: Voltage question

A non regulated supply's voltage will drop compared to the no load voltage when loaded down with a pedal. But, most pedals draw so little current that the voltage will still be above the nominal voltage rating of the supply. And, if the supply is rated for, example, 9 volts dc and 1 amp, I dont think it will come all the way down to the 9 volts unless the load is at or near the full 1 amp rating of the supply. Good reason why the wall warts that are designed for pedals and made by reputable companies are regulated supplies.

Pure laziness on my part. Would have taken less than 2 minutes to ensure it was properly protected. Even after telling Nik @ Ceriatone what I did, he offered to fix it for free! It was my fault, so I told him that I would buy the parts and fix it myself. If there's something else wrong, I'll send it to Nik. I'm getting 9VDC from the right side of the zener (0VDC from the left), so a simple swap of the charge pump should do the trick.