Is it ok to use any kind of ac adapter?

Gary Meyer · Post by **Gary Meyer** » 25 May 2004 8:23 pm

On my compressor is says to use only the ac adapter that was made for it. It seems like all 9 volt to ac adapters are the same (at least they look the same).Does one work for all or do you really have to use that brand's specific adapter? Thanks in advance.

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Eric West · Post by **Eric West** » 25 May 2004 8:32 pm

You want to be real careful to match polarity, milliamps, and I'm pretty sure non audio applications don't have certain filters.

I tried a universal one on my korg tuner and it worked fine, but it didn't on my Turbo overdrive.

Be careful.

EJL

Sidney Malone · Post by **Sidney Malone** » 25 May 2004 8:43 pm

The adapter must have the same polarity output, some of the universal ones are switchable. It must also put out the same voltage, again some of the universal ones have a choice of several different output settings. Where most adapters fall short is the milliamp output. If it's not enough the unit won't operate and could in turn damage it.

If you have a adapter that meets the power requirements of the unit, (polarity, volts & milliamps) then it will work no matter who's name is on it.

This info is normally found near where the adapter plugs in to the unit or in the spcifications of the owners manual.

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Fessy S-12U, Future MSA Millennium S-12U, Stereo Steel

Jerry Roller · Post by **Jerry Roller** » 25 May 2004 9:14 pm

Also be aware that you have to have the right size jack (plug).
Jerry

Dave Boothroyd · Post by **Dave Boothroyd** » 25 May 2004 10:28 pm

And some power supplies put out an alternating current. Alesis for example.

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Cheers!
Dave

basilh · Post by **basilh** » 26 May 2004 4:15 am

BEWARE .. what Dave says is to be taken SERIOUSLY. You MUST check if the OUPUT is AC or DC and matches the required mode of the unit you're powering.. Failure to oserve this can result in BURNT out boards especially in the case of Alesis units.
Baz

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Steel players do it without fretting

http://www.waikiki-islanders.com

Jim Smith · Post by **Jim Smith** » 26 May 2004 4:42 am

If it's an AC adapter, there is no polarity. Only DC adapters have plus and minus.

Ray Minich · Post by **Ray Minich** » 26 May 2004 6:48 am

All wall warts are not created equal. Check power output stamped onto case (as in milliamps out...). Also, be aware that the filter networks in some DC wall warts are lousy.

Yes it is a real pain to see that the wall wart for the Boss compressor costs $29.00 and one with approximate specs can be bought from Newark for $4.95. Pay the money for the good one and be done with it...

By the time one makes three trips to Radio Shack to find the right size plug for that stupid power connector (how many different diameter center pins can they come up with?), and then has figured out whether the center pin is plus or minus, and then tried the power supply and found the filtering to be terrible 'cause the stomp box hums, it's easier and a lot less frustration to get the manufacturer's recommended power pak.[This message was edited by Ray Minich on 26 May 2004 at 09:14 AM.][This message was edited by Ray Minich on 26 May 2004 at 04:09 PM.][This message was edited by Ray Minich on 26 May 2004 at 04:10 PM.]

Donald Ruetenik · Post by **Donald Ruetenik** » 26 May 2004 7:16 am

The 'warning' on your compressor is primarily intended for those that don't understand about the power requirements of the unit. This is not everybody's area of expertise. All the concerns mentioned in this topic are indeed valid. It is also intended to sell you another item if not included. But, when in doubt, purchase the recommended adapter. You'll be buying 'peace-of-mind'.

C Dixon · Post by **C Dixon** » 26 May 2004 8:57 am

Some devices require AC. Some require DC. Some require filterd voltage if it is DC. Others do not (they have their own filters and regulators). Some require more amps to work properly than others. Some indeed use postive hot and negative ground and vice versa.

The poster is correct about polarity on DC.

If your adaptor meets the requirements of ANY given device, that adaptor WILL work. The problem is how does the novice know? This is a big question and not always evident; even for the professional.

So IF in doubt, ALWAYS use the manufacturer's advice. I do not believe most are just trying to get you to buy their adaptor. Rather I believe they are more concerned with your not damaging the device.

Having said all that, by far the largest complaints I have heard is, "It hums!". The most probably cause is the subsitute DC adaptor is not filtered.

So IF the voltage is correct, the polarity is correct and the adaptor can supply the required current, THEN make sure it is filtered. It will not hurt your device IF it does not call for a filtered adaptor if you use a filtered one.

But the reverse is not true.

Again, if there is any doubt, for peace of mind and to prevent damage, do what the manufacturer tells you to do.

One final bit of information. If your device requires a given amp(s), best to use a supply with a least twice that amount of delivery capability. In other words using a an adapter with 16 amps rated will not hurt a device rated for half and amp. The reverse rarely would hurt the device. But it may work poorly; or not at all.

Example, you have a device that needs 3 amps. You hook up an adaptor with only 1 amp capability. Your device probably won't be harmed although it may not work. But ya might blow the adaptor or a fuse in the adaptor!

The best way to understand this is in your AC power to your home. That transformer on the pole outside is capable of delivering tremendous amperage. Your home devices draw what ever they need up to the fuse or circuit breaker limit.

But there is little likelyhood you gonna blow that monster out on that pole in any case. Corse yer lible to burn yo house down if'un ya bypasss dat circuit breaker, bubba

carl

Ray Minich · Post by **Ray Minich** » 26 May 2004 11:42 am

Carl, you mean to tell me pennies in the fuse box ain't code?

C Dixon · Post by **C Dixon** » 26 May 2004 11:55 am

Peter · Post by **Peter** » 26 May 2004 12:11 pm

Having said all that, by far the largest complaints I have heard is, "It hums!".

Carl, my power supply is humming, 'caus it can't remember the words!

Jennings Ward · Post by **Jennings Ward** » 3 Jun 2004 10:09 am

Word of caution! Dont hot wire it to your 440!! Unless you have plenty of insurance....... No one is that stupid..... Jennings

Joe E · Post by **Joe E** » 3 Jun 2004 10:41 am

One problem I find that no one has touched on is this:

An adpater marked 9v may not really be 9v. Sometimes they are closer to 12v until a heavy load is placed on them. A pedal may not be ehough current to pull the voltage down to its rated specs.

Use a meter to check out your supplies. Most pedals draw only about 20 milivolts. So a 200 or 300 milivolt supply should be able to power quite a few pedals.

2 to 3 times the needed amperage seems to be a good rule of thumb.

Joe E