Will 14V Blow up 9V Pedals?

[The New Steve H]

I threw out a couple of Panasonic phones that had "9V" AC adaptors. I thought I might use one for a pedal, but I measured the voltage coming out, and it was actually 16V. I used diodes to bring it down a couple of volts. Now I'm wondering: will I blow up a Blues Driver and Holy Grail if I try to use it?

Anyone know? I would think 14V would not be a big problem, but for all I know, these pedals are picky.

[The New Steve H]

I keep finding old 9V adaptors lying around, and only the ones made for pedals are close to correct. The rest are way high, like 14-16V.

[frankdrebin]

unloaded is always higher voltage.
generally speaking,overdrives are ok with higher voltages,unless they use a voltage doubler.
in modulation/delays,digital chips work with voltage regulators so it is possible.

[The New Steve H]

I love screwing around with cheap and free stuff, but I think I'll just get another $14 wall wart that already works.

I don't understand why the other warts are so far off. I do realize that a power supply will sag when something draws current, but the Boss and 1 Spot warts I own are a little over 9V from the start, so I assume they must have better regulation or bigger capacitors or something.

[Littlewyan]

Some 9V Adapters are so cheap that they rely on the load to bring them down. Some can't even supply the max current they're rated for.

[Firestorm]

I have a drawerful of adapters that are not even close to spec. Mostly AC to DC. I think they're all just crap so you have to buy more.

[R.G.]

I threw out a couple of Panasonic phones that had "9V" AC adaptors. I thought I might use one for a pedal, but I measured the voltage coming out, and it was actually 16V. I used diodes to bring it down a couple of volts. Now I'm wondering: will I blow up a Blues Driver and Holy Grail if I try to use it?

Anyone know? I would think 14V would not be a big problem, but for all I know, these pedals are picky.

There is no way to tell. Each pedal uses internal parts that may or may not have some excess voltage capability. For instance, some pedals designed for 9V operation use 10V rated electro caps. A steady diet of 14V is likely to be fatal. Still others use 25V rated stuff even if the pedal is supposed to only be used on 9V.

Like the song says, some they will and some they won't, and some it's just as well.

I keep finding old 9V adaptors lying around, and only the ones made for pedals are close to correct. The rest are way high, like 14-16V.

Ones made for pedals are regulated to be correct. Ones made for phones and such rely on the device they power to accept and regulate a less well-mannered power supply. They are solving different problems.

unloaded is always higher voltage.
generally speaking,overdrives are ok with higher voltages,unless they use a voltage doubler. in modulation/delays,digital chips work with voltage regulators so it is possible.

Again, some they will and some they won't. Some older Japanese overdrives are the ones I was thinking about with 10V caps. Generally speaking, generally speaking isn't worth much here. When you put more than the rated voltage on a pedal, you're betting the price you paid for the pedal that it will be OK. I guess it all depends on how lucky you feel.

I don't understand why the other warts are so far off. I do realize that a power supply will sag when something draws current, but the Boss and 1 Spot warts I own are a little over 9V from the start, so I assume they must have better regulation or bigger capacitors or something.

In the case of the 1Spot, it's designed to put out the voltage of a new/fresh alkaline 9V battery, which is 9.3 to 9.5Vdc. The big difference is active regulation. The power supplies which are designed to put out a steady, quiet voltage do so (mostly at least). The others are designed to put out enough power for the device (ie. phone or whatever) to regulate for itself.

The difference with regulation is this: the smaller a transformer is, the more poorly it can hold a steady output under load, for a host of technical reasons. So to get a certain minimum power to the answering machine or whatever, they have to jack up the unloaded voltage so that when it sags down, there's enough.

A regulated wall wart makes more than it needs internally too, but it is also designed to carefully let out only the *correct* amount of voltage from no load to full load.

Again, solving different problems.

Some 9V Adapters are so cheap that they rely on the load to bring them down. Some can't even supply the max current they're rated for.

I have a drawerful of adapters that are not even close to spec. Mostly AC to DC. I think they're all just crap so you have to buy more.

In a market where people spend hours on the internet to find which of several nearly-identical things is a few bucks cheaper, companies have figured out that if you have to save money somewhere, save it where it's not one of the big advertising points.

And yes, there are some really under-designed, marginal things out there. But it's naive to lump all the issues together. As for them being crap so you have to buy more, when was the last time you had to replace a [whatever] because the wall wart died?

I'm guessing quite a while because you have that drawer of adapters.

And if you have a drawer full of not-meeting-spec adapters - why not trash the lot of them and have a free drawer to store stuff that's not crap?

[Firestorm]

Like I've always said, Keen is too smart to hang with us. I keep the drawerful of crap because it has voltage and current. The ones that didn't are gone. A lot of boxes are self limiting, the best force DC polarity regardless of source (which won't work, but won't kill them either). R.G., sometime I hope to meet you.

[The New Steve H]

Fooling with my warts has been a useful experience. I learned I should never take the voltage rating on a wart seriously, for pedal use. I also fixed one wart so it puts out 12V, which is supposed to improve the sound of Tube Screamers.

The accumulation of information continues.

[sliberty]

As R.G. pointed out, capacitor voltage ratings can be the issue as to whether or not a pedal can handle it. Many pedals state in the there docs that they can handle 18 volt power supplies ("for added headroom" is usually the marketing line). But if a pedal doesn't state this, you might be at risk.

[xtian]

I often wish we had a Like button here.

[R.G.]

Like I've always said, Keen is too smart to hang with us.

You haven't seen all the mistakes I make...

R.G., sometime I hope to meet you.

I'll be at NAMM next week if you get to Anaheim and can get in. Check the exhibitors list for "Truetone".

Fooling with my warts has been a useful experience. I learned I should never take the voltage rating on a wart seriously, for pedal use.

There's a big separator there - the word "regulated". Many modern and some not-so-modern warts are regulated, and their output is pretty constant over their rated load range. If it doesn't say "regulated" in the manufacturer's literature, assume not regulated until proven otherwise.

One of the quirks of Mother Natures's laws is that a little transformer has to use tiny, fine wire for winding and this wire has high resistance. So there's more resistance in the windings and therefore more resistive sag when the transformer runs. Big transformers - we're talking several pounds on up - may have sag in the 2-5% range because they are big enough to use comparatively big copper wires. Little ones may sag 15-40% over their no-load to full-load range.

In one of those bits of deceptive language, if you read a transformer maker's web site, they talk about transformer "regulation", which is of course no such thing. That's the no-load to full-load sag, but called something more pleasant for customers to read.

Transformer-inherent sag/regulation is no big deal for a kind-of-constant load. It doesn't matter if the transformer ranges from 20 down to 10 volts depending on load if the load is always going to be such that it's 10V. So the single-design wall wart for an answering machine can use smaller, cheaper wall warts and let them sag down to just the right voltage under load. Doesn't matter - to the answering machine.

The governments have pretty much collectively decided that you cannot be trusted to use old-style transformer wall warts and not ruin the planet, so they have crafted 'energy conservation laws' that have the intended side effect of making wall warts be complex switching power supplies, with fines and such for anyone selling an old-style wall wart.

That means that in the future wall warts will mostly be regulated and only put out the specified DC, but they will also put out copious switching noise unless some care is taken to make them quiet. So the old-style unregulated warts will soon be a thing of the past.

They'll just be too noisy for repurposing-pedalboard use.

[cbass]

Hell Im more impressed that RG can break up quotes.Ive been tryingf to fugure that out for years I guess his electronics knowledge is pretty impressive also

[Firestorm]

Ahh, the doctrine of unintended consequences. History of government regulation in a nutshell. Remember Carters oil "crisis?” They sent tank trucks out less than half full to make sure nobody got more than their share and wasted God knows how much energy in the process. Had oil tanker ships stacked up outside the ports like LaGuardia at Thanksgiving, ' cause the refineries couldn't handle the input since the output was so constricted. Adam Smith was spinning in his grave so fast, he could have made a few million Bbls.

No NAMM for me. Enjoy. Sell hard.

[davent]

Hell Im more impressed that RG can break up quotes.Ive been tryingf to fugure that out for years I guess his electronics knowledge is pretty impressive also

Just copy your post to clipboard when writing a reply, back-up to the thread, quote a new post, plug in your clipboard, back and forth, back and forth.

Some forums have "insert quote" with the posts when you are replying to a thread, makes it simple.
dave