Electronics power help
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Discussion

Stamp

Original Poster:

3,609 posts

265 months

Sunday 1st February 2009
quotequote all
I have bought an Alesis Microverb 2 and need a power supply. The book says.. 9v AC 5 volt-amperes, through a 3.5mm jack plug.
Now, I am not sure what to look for. Is this 500mA? I have found this : Output: 9v AC 1000mA (1A). Will this do?
Also, is there a right and wrong way around for the positive / negative part of the jack, or are they usually end pin negative?

GreenV8S

31,014 posts

313 months

Sunday 1st February 2009
quotequote all
Stamp said:
I have bought an Alesis Microverb 2 and need a power supply. The book says.. 9v AC 5 volt-amperes, through a 3.5mm jack plug.
Now, I am not sure what to look for. Is this 500mA? I have found this : Output: 9v AC 1000mA (1A). Will this do?
Also, is there a right and wrong way around for the positive / negative part of the jack, or are they usually end pin negative?
There is often a simple diagram next to the connector showing which is positive and negative. Although there is a convention, I don't think it's widely enough adopted to be trusted if you're mixing brands.

5 volt-amperes means Volts x Amps = 5. At 9v that means it's taking about half an Amp (i.e. 500 mA). So your 1000mA supply would be more than adequate.

David87M3

1,464 posts

263 months

Sunday 1st February 2009
quotequote all
if it says AC there wont be a +/- symbol

try contacting manufacturer if poss. most supplies you get in shops provide dc output

Stamp

Original Poster:

3,609 posts

265 months

Sunday 1st February 2009
quotequote all
GreenV8S said:
Stamp said:
I have bought an Alesis Microverb 2 and need a power supply. The book says.. 9v AC 5 volt-amperes, through a 3.5mm jack plug.
Now, I am not sure what to look for. Is this 500mA? I have found this : Output: 9v AC 1000mA (1A). Will this do?
Also, is there a right and wrong way around for the positive / negative part of the jack, or are they usually end pin negative?
There is often a simple diagram next to the connector showing which is positive and negative. Although there is a convention, I don't think it's widely enough adopted to be trusted if you're mixing brands.

5 volt-amperes means Volts x Amps = 5. At 9v that means it's taking about half an Amp (i.e. 500 mA). So your 1000mA supply would be more than adequate.
Sadly, no diagram. Just says 9v AC.
Thanks for the conversion.

V8A*ndy

3,697 posts

220 months

Sunday 1st February 2009
quotequote all
http://en.woodbrass.com/ALESIS+P3+9V+AC+POWER+SUPL...

HTH

If you can wait until tomorrow I will have a look in the emergency PSU box in the studio for you. Might just be one there.



Stamp

Original Poster:

3,609 posts

265 months

Sunday 1st February 2009
quotequote all
David87M3 said:
if it says AC there wont be a +/- symbol

try contacting manufacturer if poss. most supplies you get in shops provide dc output
I tried the tech desk at the UK Alesis and they couldn't help me. It was too old for them!

V8A*ndy said:
http://en.woodbrass.com/ALESIS+P3+9V+AC+POWER+SUPL...

HTH

If you can wait until tomorrow I will have a look in the emergency PSU box in the studio for you. Might just be one there.
Cheers Andy. I had found that one, but it has a more usual dc plug rather than the 3.5mm jack.

V8A*ndy

3,697 posts

220 months

Sunday 1st February 2009
quotequote all
Shirely thats the correct item?

Can you post a pic of the socket on the verb? I know Quadra verbs use a din connector but the item you have I once ran off an old boss AC/DC adapter when I was stuck once as far as I can remember.......


As a matter of interest what are you using it for?

Stamp

Original Poster:

3,609 posts

265 months

Sunday 1st February 2009
quotequote all
Andy, here you go...



I hope to use it for guitar with an ampmaker valve amp


Edited by Stamp on Sunday 1st February 20:23

GreenV8S

31,014 posts

313 months

Sunday 1st February 2009
quotequote all
Stamp said:
Sadly, no diagram. Just says 9v AC.
Thanks for the conversion.
Sorry, I had missed that it is expecting AC rather than DC.

With AC obviously there is no issue with polarity, so you can't go wrong. Finding an AC 9V supply might be tricky though since almost all low voltage domestic appliances run on DC. It may be that this device will run OK on DC but there's a small (imo) risk that it could be damaged by it so I'd look for an AC supply first.

marshalla

15,902 posts

230 months

Sunday 1st February 2009
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thunderbelmont

2,982 posts

253 months

Sunday 1st February 2009
quotequote all
5VA @ 9V - 5Watts thereabouts.
W=VxA, therefore, 5VA = 9V x 0.556A~

I have had a look at a power supply for a Netgear ADSL modem, which I was sure had a 9v AC supply - however it's 12v.

Some of those naff novelty "disco" lights, or similar, often have AC supplies, usually 9v, and usually rated around 1A.

Just a case of taking off the coaxial power connector and fitting the required plug.

V8A*ndy

3,697 posts

220 months

Sunday 1st February 2009
quotequote all
Bugger!!!! Thats a real old one alright.

I'd go with that Maplin unit above. As if it doesn't work, then they will take it back no probs.

Have you had the verb going before or have you just aquired it. Does it work ok?

Stamp

Original Poster:

3,609 posts

265 months

Sunday 1st February 2009
quotequote all
Andy, I have just bought it and need the psu to try it.

I think I have found one on ebay that will do. 9v 1000mA.
So there is no polarity issue with the 3.5. I can just cut off the old plug and put the jack on, not worrying about centre pin positive?

V8A*ndy

3,697 posts

220 months

Sunday 1st February 2009
quotequote all
As far as I know there should be no issue if the power supply states its AC. This is due to reactance and other issues of the device (Sorry school days was a while ago).

Take a look here. I have just realised those verbs were used for rack mounting back in the day and were often looped from one supply.

http://accessories.musiciansfriend.com/power-essen...


FOUND THIS http://www.thomann.de/gb/visual_sound_adapterkabel... should work with http://www.thomann.de/gb/behringer_x_v_amp_netztei...

They have loads of PSUs on there to. I have found if you e-mail them they are rather helpful.





Edited by V8A*ndy on Sunday 1st February 22:01


Edited by V8A*ndy on Sunday 1st February 22:07