Question about adapters

Heabow

More cowbell!
Aug 24, 2011
1,992
31
48
France
Hey,

I'm about to buy a used FMR Audio RNC 1773 compressor but the seller used it with a wrong adapter. On the comp, it's written 9V/500mA and it's originally sold in stores with a 9V AC/1A adapter (I'm located in France). The guy used it with a 12V/1A.

He told me that the compressor works perfectly but I'd like to know if this can cause damages.

Thanks for your help!
 
considering it is an AC adapter the puser supply built in will have regulators keeping everything where it should be. Works the regulator harder than it should but that isn't that much of an issue.

a look at the user manual should give you maximum ratings should let you know what is safe.
 
Thank you! Here is the spec sheet of the 1773 but it looks like chinese to me to be perfectly honest :) (yes it's a shame to not know this kind of basic stuff) So with these informations, maybe you can confirm if his 12V/1A adapter is a potential risk or not... http://www.fmraudio.com/rncSpecs.htm
 
I'd recommend calling FMR and asking what their opinion is. When I busted the cord that came with my RNC, they told me to get a 9V/600ma adapter instead of a 9V/500ma as indicated on the back. I went to my local Radio Shack, got the cord they recommended and it didn't work.

I did some research on adapters for the FMR RNC. This works great for me:
http://www.jameco.com/webapp/wcs/st...Id=10001&ddkey=http:StoreCatalogDrillDownView
 
I would look for something slightly beefier than 500mA though, if it can pull close to 500mA and the power supply is maxed out at 500mA, then it will start getting noisy and you will look some headroom, not good by any means. If you can get a 9VAC/1A 5.5mm x 2.1mm adapter then you should be pretty set.
 
Thanks for the details. But does it mean the seller's 12V AC/1A adapter cannot cause damages to the RNC?
I gotta know exactly because I'm about to buy it... or not.
 
I would look for something slightly beefier than 500mA though, if it can pull close to 500mA and the power supply is maxed out at 500mA, then it will start getting noisy and you will look some headroom, not good by any means. If you can get a 9VAC/1A 5.5mm x 2.1mm adapter then you should be pretty set.

Very true, I tried several 600ma and a couple 500ma that did some nasty stuff to the headroom/overall sound of the compressor. The 500ma one I linked has been working (surprisingly) great though.

I'm not sure about damage from a 12V AC/1A adapter though. As I said, calling FMR and see what they have to say would be advisable
 
Here is what FMR says:
"I'd recommend the 9VAC version...the other (12VAC) will unduly stress some of the components. If it helps, you can use a power supply (9VAC) with as little as 350mA..."
So what I understand here is that the comp could possibly be damaged by a 12VAC. I don't kow if it's worth buying it as it works now but could break in my hand in 2 weeks even if I use it a correct power supply :erk:
 
Not much of a help here but I just wanted to chime in and say the power supplies they come with aren't very sturdy. Mine works but the pins on it have come loose so I can't really bring it around to gigs anymore in case someone knocks off it. I used to run it on my master at gigs so it cutting in and out with a loud bang when it gets moved a little sucks!

I hate those type of power supplies in general. I also have huge problems with a Joe Meek one I had where the wire became frayed near the end by the adapter and have had multiple guitar power supplies bend, fray or die. IEC's all the way when possible!
 
I finally decided to not buy it. Don't wanna risk to get a damaged stuff. I'll save some more money to buy one new. Thanks guys for your help tho!