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peebo
Bronze Member
Australia
54 Posts |
 Posted - 07/07/2008 : 10:50:33
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had a quick rummage through and cant find a relevant thread, doesn't mean there isnt one...
anyway, i've got 4 pedals, one being a Zoom 707II, and i plan to add another soon. I've been powering each one off it's own transformer but it's a pain, so I made a daisy chain to power all of them from the one
it all works as far as power goes, all the polarity is correct. I found on this site the Boss pedals I have draw about 10mA, and the zoom draws 300mA, the adaptor I have is 500mA, so should be no problem
however, if I connect more than 2 pedals, I get a background noise/hum and the tuner in the Zoom indicates a hum as well (by picking up a note and not recognising anything from the guitar)
it does it whichever 2 pedals I have on, and from any of the plugs on my daisy chain
any theories as to what is going wrong?
is there a wiring diagram of how it should be so I can compare as make sure i've done it right?
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pedals 4 pv
Platinum Member
Canada
1351 Posts |
Posted - 07/07/2008 : 20:26:50
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Run the multi from its own supply and the pedals from the daisy chain. You need two adaptors.
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Edited by - pedals 4 pv on 07/07/2008 20:27:09 |
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peebo
Bronze Member
Australia
54 Posts |
Posted - 07/07/2008 : 22:19:28
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| I thought of that, if i take the multi out completely (power and signal) I still get the hum.... |
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jack
Platinum Member
USA
1418 Posts |
Posted - 07/08/2008 : 02:21:18
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| Maybe its a grounding issue? Is the daisy chain you made properly grounded? |
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peebo
Bronze Member
Australia
54 Posts |
Posted - 07/08/2008 : 02:59:51
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I think I'll just get my multimeter out, make sure the adaptor is giving out what it's supossed to, and if it is then i'll go buy a daisy chain ;)
that's the easiest option  |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 07/08/2008 : 09:23:56
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Hi peebo
Is it a fully regulated power adapter?
And which brand & model is it?
Regards Dr. Bob |
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peebo
Bronze Member
Australia
54 Posts |
Posted - 07/20/2008 : 11:41:43
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quote:
Originally posted by Dr. Bob
Hi peebo
Is it a fully regulated power adapter?
And which brand & model is it?
Regards Dr. Bob
nope. just some cheap thing that came with the Zoom
I bought a daisy chain from Gallins in Melb on the weekend while I was there, and it still does it, so I guess it's time to get a new adapter ;)
any recommendations? |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 07/20/2008 : 14:43:25
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Hi peebo
Please read the labels on both or any of the adapters that you have.
And tell us what they say, specifically if you can see something like ( regulated - fully regulated)?
And the BRAND?
or are your power adapters the kind that have a switch selector for multiple output voltages.
Some people have had trouble trying to run Zooms in a daisy chain with other pedals.
And have found that they had to run the Zoom from it's own supply.
Someone else found that their Zoom's pwr adapter didn't work, or work well with Boss pedals, even when used on their own.
Regards Dr. Bob |
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peebo
Bronze Member
Australia
54 Posts |
Posted - 07/21/2008 : 04:16:02
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it's a brandname-less 9v 500mA adapter, not regulated.
it came with the Zoom but isnt Zoom brand
the Zoom is currently out of the chain, so it's just HM-2 -> OD-2 -> Ibanez PT-9 phaser
with any 2 pedals it's fine, 3 or more and it makes the hum |
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FRANZONI
Double Platinum Member
Ireland
3543 Posts |
Posted - 07/21/2008 : 12:31:10
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hi peebo
i'm one of the people the doc is referring to,i had some serious hum issues and the DD-3 just wouldn't work at all off the zoom power supply i have..it was a pity because the ACA boss pedals DS-1,CS-3 and my OD-2 seemed to sound really good with it..... but it caused major feedback and hum issues when i turned them on.... |
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peebo
Bronze Member
Australia
54 Posts |
Posted - 07/21/2008 : 13:11:18
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I couldnt find my multimeter tonight, but i found a cheap nasty one I was given, and I threw that on the adapter and it was reading over 14 volts. out of a 9v adapter
I rang my dad (a recently retired electrical engineer) and while these things are out of his experience not being trains, he did believe that this means it's stuffed, particularly not being a regulated supply.
so I'll buy a new regulated supply on the condition that i can return it if it doesnt solve the problem but that should fix it.
if i have to run the zoom off it's own that's ok, i just want rid of the hum, and to not have an individual supply for each pedal!!! 2 is better than 5 ;) |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 07/21/2008 : 15:43:36
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quote:
Originally posted by peebo
I couldnt find my multimeter tonight, but i found a cheap nasty one I was given, and I threw that on the adapter and it was reading over 14 volts. out of a 9v adapter
Hi peebo! 14V out of a "cheap and cheerful" unregulated 9V adapter is actually about right... What you will also find is a heap of ripple on the output when it is loaded down (you would need a scope to see that - most multimeters wont register it).
Anyway, a PSA supply (or equivalent) won't do that and should solve the problem. |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 07/21/2008 : 17:07:42
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Hi Guys
quote:
Laurie
Hi peebo! 14V out of a "cheap and cheerful" unregulated 9V adapter is actually about right... What you will also find is a heap of ripple on the output when it is loaded down (you would need a scope to see that - most multimeters wont register it).
Not to mention that you are measuring the power adapter without a load attached, know as (a no Load measurement).
The 14V will drop somewhat, depending on the amount of current you draw from it.
Seeing you have a non regulated power adapter, that will be the reason you are getting so much hum, with 3 pedals.
You failed to mention, who much current it can supply.
I'm guessing, that the you are drawing a lot of current from it, & it's a low current type of a few 100 milliamps.
The Zoom will probably be drawing most of the current, due to the DSP processor in the Zoom Multi-effects.
Then you won't have enough current to power the other pedal, not to mention that the adapter will probably be dropping a few volts under the 3 pedal load.
And it's poor regulation.
Can you tell us how much current the adapter can supply?
Or post a pic of it showing the label.
Apologies for the Techno-Babble.
Regards Dr. Bob
PS
If you can solder?
You could always buy a few bits & make it a regulated power supply.
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Edited by - Dr. Bob on 07/21/2008 17:08:45 |
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peebo
Bronze Member
Australia
54 Posts |
Posted - 07/21/2008 : 23:42:26
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the first post states it's a 500mA supply ;)
the Zoom is not connected atm so it's irrelevant
but yes, 14V with no load, so loading it up will be causing the problem, even though the 3 pedals only draw a total of around 30mA
as for making it regulated, I did think of that option, but being a cheap and cheerful adapter i'll probably just replace it with something decent since I have another pedal in the mail and plans to buy more ;) |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 07/22/2008 : 09:36:28
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quote:
Originally posted by peebo
the first post states it's a 500mA supply ;)
the Zoom is not connected atm so it's irrelevant
but yes, 14V with no load, so loading it up will be causing the problem, even though the 3 pedals only draw a total of around 30mA
as for making it regulated, I did think of that option, but being a cheap and cheerful adapter i'll probably just replace it with something decent since I have another pedal in the mail and plans to buy more ;)
Apologies peebo
I guess I just missed that in your earlier post.
Any reason you might not just build a simple LM7809 three terminal regulator, externally to your current unregulated supply?
Laurie, they guys & I would help you out.
Regards Dr. Bob |
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peebo
Bronze Member
Australia
54 Posts |
Posted - 07/22/2008 : 12:41:50
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quote:
Originally posted by Dr. BobAny reason you might not just build a simple LM7809 three terminal regulator, externally to your current unregulated supply?
Laurie, they guys & I would help you out.
Regards Dr. Bob
I guess I could, but I wonder if it would just be less hassle to get a new adapter and know it works ;) |
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Topic |
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pedal power
