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cyberpunk409
Bronze Member
Australia
56 Posts |
 Posted - 04/25/2007 : 14:55:25
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hey guys, please excuse my ignorance, but i've got no idea what the difference is between Regulated vs Unregulated Power Adapters.
I'm currently using a 9v UNREGULATED power adapter (1200ma) to power my pedals, good or bad?
Should i get a REGULATED adapter instead? and if so, why?
thanks :) |
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DeFrag
Moderator
USA
3409 Posts |
Posted - 04/25/2007 : 16:27:59
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A regulated power supply, contains an circuit the function of which is to supply a stable current, or more commonly voltage, to a circuit or device that must be operated within certain power supply limitations.
The type of stabilization used may be restricted to ensuring that the output remains within certain limits under various load conditions or it may also include compensation for variations in its own supply source.
In essence, a regulated power supply acts like a voltage regulator, current regulator, or both. It simply provides a more stable power source for those devices that are sensitive to variances. |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 04/25/2007 : 17:44:22
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quote:
Originally posted by DeFrag
A regulated power supply, contains an circuit the function of which is to supply a stable current, or more commonly voltage, to a circuit or device that must be operated within certain power supply limitations.
The type of stabilization used may be restricted to ensuring that the output remains within certain limits under various load conditions or it may also include compensation for variations in its own supply source.
In essence, a regulated power supply acts like a voltage regulator, current regulator, or both. It simply provides a more stable power source for those devices that are sensitive to variances.
Thanks defrag.. 
And Unregulated supplies usually only contain 4 diodes & a large (if your lucky) filter capacitor.
The voltage specified, can vary quite a bit, depending on the amount of load that you put on it.
More load = less voltage.
Less load = more voltage.
You may find, that if you measure the output of your unregulated supply,
when you have it switched to say 9V, it will be as high as 12V depending on the amount of load.
(assuming it has switchable voltages)
The ones I use at work are 1000mA (1 amp) switchable plug packs.
If I need 9V - I set the switch to the 6V setting, if I need it to be 12V, I set it to the 9V setting.
On the max setting of 12V, that unit outputs about 16V to 18V.
And all this varies with different manufactures, but seems to be dependent on units with lager than 300-500mA of current.
So please keep that in mind.....
The regulated power supply will also have, DRAMATICALLY LOWER hum & noise.
The LM7809 chip used in the PSA type adapter, has a noise figure of around -100dB or more.
that's very quiet.
Regards Dr. Bob  |
Edited by - Dr. Bob on 04/25/2007 17:52:14 |
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sp-1
Platinum Member
Germany
1454 Posts |
Posted - 04/25/2007 : 18:09:16
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Dear Dr.Bob you are a doctor.... how come that my mij dd-3 and ns-2 aren't working properly when I use a roland acb (9v 1200 mA)adapter ? they work fine with a psa.
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cyberpunk409
Bronze Member
Australia
56 Posts |
Posted - 04/25/2007 : 18:43:09
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dr bob, you said:
The regulated power supply will also have, DRAMATICALLY LOWER hum & noise. The LM7809 chip used in the PSA type adapter, has a noise figure of around -100dB or more.
that's very quiet.
When you refer to a "PSA type adapater" using a LM7809 chip, does that include MOST (maybe all?) regulated power supplies that you can buy from any electronics stores, or do you essentially have to buy one designed for musical instrument pedals such as the genuine BOSS brand ones? |
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DeFrag
Moderator
USA
3409 Posts |
Posted - 04/25/2007 : 20:00:33
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quote:
The voltage specified, can vary quite a bit, depending on the amount of load that you put on it.
More load = less voltage.
Less load = more voltage.
Additionally, at a given voltage:
More load = more current drawn
Less load = less current drawn
Changing load requirements actually draw the current they need. |
Edited by - DeFrag on 04/25/2007 21:57:19 |
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midibuddy
Silver Member
Ecuador
285 Posts |
Posted - 04/25/2007 : 20:36:15
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| What about the ZOOM power adapter? Is it any good? I got one, it's 9V, and center negative, so I asume I can use it with BOSS pedals... is it regulated? What are your opinions on this one? |
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midibuddy
Silver Member
Ecuador
285 Posts |
Posted - 04/25/2007 : 23:29:22
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FRANZONI
Double Platinum Member
Ireland
3543 Posts |
Posted - 04/26/2007 : 00:27:19
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quote:
Originally posted by midibuddy
What about the ZOOM power adapter? Is it any good? I got one, it's 9V, and center negative, so I asume I can use it with BOSS pedals... is it regulated? What are your opinions on this one?
hey midibuddy.....how are you pal...?
i have a zoom supply on my board i use the boss one to power the pedals and the zoom to do the wah on its own...when i was using the zoom supply on the pedals its brought a lot of feedback and hum in the od2/ds1/cs3(these are aca pedals) and the dd3's wouldn't work off it at all even though the lrl's lit up on the pedal.... although it works fine with the wah ...if i get a chance i'm going to get a one spot supply...it has a 1000ma where the boss has only a 200ma supply i think a dd3 takes about 55ma on its own.....another thing i noticed ...and this might have no basis in science....even though the hum factor with the zoom adapter was bad i thought the cs3/od2 and the ds1 sounded a bit better and the lrl was brighter even though stinkfoot assured me the last time this subject came up that there is no reason why this should be....
p.s were back rehearsing with a new bass player first gig in 3 weeks..... |
Edited by - FRANZONI on 04/26/2007 00:28:52 |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 04/26/2007 : 12:02:37
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quote:
Originally posted by sp-1
Dear Dr.Bob you are a doctor.... how come that my mij dd-3 and ns-2 aren't working properly when I use a roland acb (9v 1200 mA)adapter ? they work fine with a psa.
Hi sp-1
I am not familiar with that power pack.
I had a bit of a look around the web, but couldn't find a decent picture of the label.
What was the Roland ACB, designed for, or is it a general purpose power adapter?
Are yo able to send me a pic of the label, on the ACB, so that I can read it.
Regards Dr. Bob ..
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 04/26/2007 : 12:41:33
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quote:
Originally posted by cyberpunk409
dr bob, you said:
The regulated power supply will also have, DRAMATICALLY LOWER hum & noise. The LM7809 chip used in the PSA type adapter, has a noise figure of around -100dB or more.
that's very quiet.
When you refer to a "PSA type adapter" using a LM7809 chip, does that include MOST (maybe all?) regulated power supplies that you can buy from any electronics stores, or do you essentially have to buy one designed for musical instrument pedals such as the genuine BOSS brand ones?
Hi cyberpunk409
Nice to see another Aussie here.
Most regulated plug packs-adapters, that you buy for general use, have an LM317T programmable 1.2V to up to 37V (if the transformer can get that high)
Regulator IC in them, the LM317T, is programmed with a simple resistor & switch to get the various output voltages, or with a pot or trim pot.
Typically 4.5V - 6V - 9V 12V
some may only be 6V & 9V or 9V & 12V
it doesn't matter as long as you can set it to somewhere around 9V DC.
The LM317T is from the same family of IC's as the LM7809
the LM78 series of Positive 3 Pin regulators, are fixed voltages.
5V = LM7805
8V = LM7808
9V = LM7809
12V = LM7812
Where the 317 has a programmable output voltage.
Essentially it's the same IC, & does the same Great Job of Regulating the voltage, Hum & noise.
For a lot of manufactures, it's easier & more cost effective, to only stock the 317 regulator.
So as long as you get a fully regulated adapter, you should be fine.
But unless you actually open up the adapter & look inside it, you will never really know what they used.
Unless they state it in the specification & technical notes, on the box.
So you don't have t buy a purpose built, or as you put it, one designed for musical instrument pedals.
Just make sure it's a regulated one.
I'm not sure why & what the problem with SP-1's Roland ACB adapter & his DD-3 & NS-2, is?
There are also other types of adapter, like the "One Spot" & there is one on EvilBay Aust. that are called, switching power supplies, like the ones you find in a computer.
Switching power supplies don't have a heavy transformer in them, & are capable of delivering a lot of current in a small LIGHT package, & these are regulated as well.
Your mobile phone charger is probably a switching power supply-adapter
Don't ask me how good they are, but reports on the net seem to be good to excellent.
I recently modified a 12V 3-4 amp switching power supply, to give out about 9.5V.
I can run one Shed Load of pedals off it.
It's small & light weight, it was off a 12 inch LCD monitor, that decided it crack, when a customer, punched the SHED out of it.  
Must have been one bad spreadsheet.
Hope this all helped
Regards Dr. Bob
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Edited by - Dr. Bob on 04/26/2007 12:47:31 |
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sp-1
Platinum Member
Germany
1454 Posts |
Posted - 04/26/2007 : 12:42:23
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Hi Dr.Bob
It came with a roland mt-32 sound module.
I send the picture to your personal mail cause I can't upload it. |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 04/26/2007 : 13:07:06
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quote:
Originally posted by sp-1
Hi Dr.Bob
It came with a roland mt-32 sound module.
I send the picture to your personal mail cause I can't upload it.
Hi SP-1
Ok, that's fine, I have trouble uploading pics sometime as well.
Your pic just pooped up in my mail box.
I can't see what the problem might be, but let me take a couple of educated guesses,
& can you open it up, for an inside pic, or is it welded glued together.
Maybe the capacitor in it has aged & dried out, making the output less than 9V, can you measure it with a meter?
I get lots of adapters with dried out caps in them & low output voltage. especially the older ones, & the MT32 came out a long time ago, maybe more than 10 years ago?
It's been a long time since I used or had a MT32 here for service.
Maybe the hole in the tip of the ACB connector is 2.5mm and the pins on the pedals are 2.1mm, so the plugs don't connect properly.
thsi is hard to mesure, unless you have a 2.5mm & a 2.1mm drill bit to put into the hole on the connector, to see which size it is.
If you have really good eyesight, look at the socket on the MT32 & the pedals, see if they are the same size or the one on the MT32 is bigger.
The adapter just maybe faulty, can you measure the output?
What is it that the ACB doesn't do, you didn't explain it properly.
On a different note, you can mod the output op-amps in the MT32 & it will be less noisy,
I did a few of these many years ago, but can't remember the IC part numbers, there might be something on the web about these days.
Any good quality low noise op-amp should do.
Regards Dr. Bob
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sp-1
Platinum Member
Germany
1454 Posts |
Posted - 04/26/2007 : 13:43:32
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Well the output measures 14,6 v while the label says 9 v
The acb worked fine with my mt-2 so I tried it on a dd-3 wich I bought on the internet and...... nothing only the original signal the led lighted but.... no delay. so I mailed the guy that he sold me shit etc etc.... before I send it back I tried it with an old psa and....it worked fine, so I kept the dd-3 .
When I use the acb on a ns-2 the mute function doesn't work.
I send a mail to roland benelux and they told me that it shouldn't be a problem and I can use both the psa and acb adapter. |
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cyberpunk409
Bronze Member
Australia
56 Posts |
Posted - 04/26/2007 : 18:42:33
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thanks for your lengthy response dr.bob.
i bought a $35 regulated power supply (9v 1100ma) today from a music store. However, it doesnt actually say "Regulated" anywhere on the adapter! I find that the more pedals i add (up to 5), the louder the amp humming gets. So problem NOT FIXED. It was a cheap pedal and like i said, i have no proof that it's regulated.
Some professional regulated power supplies that ive seen online go for $250, so obviously there has to be SOME difference in quality from a $35 to $250 adapter.
SHould i take the adapter back and get a better quality one (i.e. more expensive) ??? |
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FRANZONI
Double Platinum Member
Ireland
3543 Posts |
Posted - 04/26/2007 : 20:26:34
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| cyberpunk....as soon as i got a boss adapter to power the pedals the hum went out of my rig.......sometimes still get it very faintly but i'm running two amps in stereo so this has to be expected with earth loops etc but its nothing i can't live with ... |
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Regulated vs Unregulated Power Adapters
