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DIY Stompboxes => Building your own stompbox => Topic started by: jimbob on April 16, 2004, 03:43:32 PM

Title: 18V POWER SOURCE? how?
Post by: jimbob on April 16, 2004, 03:43:32 PM
My new mxr m 108 eq needs a 18v power source and i cant find one-- i thought about using 2 batteries togather than conn that to a plug to conn to the effect. Problm is i went by the diect. on the diy faq and there are no pics..i re read many time and still dont really get it..can anyone show/draw how to connect 2 batteries togather to get 18volts- from there ill solder the leads to a plug to fit into the jack..

this is all untill i can get a new one from dunflop mfr/mxr

thanks all


jim
Title: 18V POWER SOURCE? how?
Post by: phillip on April 16, 2004, 04:06:23 PM
Jim, Danelectro makes an 18V power adapter...it's the same type as their DA-1 "zero hum," it's just an 18VDC output instead of 9VDC.  We ordered some for some people when I worked at a guitar store, so a local guitar store should be able to get them.  The Danelectro model number is "DA-2" and they cost about $13 or $14.

Phillip
Title: 18V POWER SOURCE? how?
Post by: Mark Hammer on April 16, 2004, 04:21:07 PM
Will it take batteries or does it need to use an external supply?  Some pedals require so much current that they simply omit a space for batteries.  Although batteries can certainly be wired up to sub for an external DC supply, the odds of any reasonable battery life is pretty slim - generally, if batteries will quickly croak, manufacturers steer users away from them.

If you ARE game until you find a supply, simply take a pair of normal battery snaps, solder a black lead from one to the red lead on the other.  Now solder the remaining red lead to the positive/hot terminal on the plug that goes into the wallwart socket, and the black to the negative/ground terminal.

When pedals will use either internal batteries OR wallwarts, the plug/socket is almost always oriiented such that the external/shaft conductor is positive and the internal/tip conductor is ground.  When pedals use ONLY wallwarts (i.e., no battery compartment)  it's a bit of a crapshoot.  Since the plug does not have to bump a contact out of the way to switch over from battery to external power, the manufacturer can elect to use either the outside OR inside conductor as pos/hot.  I can't tell from Dunlop's literature which orientation this one is.

The manual for the M-108 (http://www.jimdunlop.com/products/electronics/mxr/products/m108.html) does not specify power requirements, but indicates use of their DC Brick power block as a possibility, which can supply up to 208ma., and provides no hint of battery operation.  The presence of 12 LEDs in addition to the EQ itself suggests that wiring up a pair of 9v batteries will not last the afternoon, my friend.

If you can't easily score an 18v supply,one thing you can do is to score a higher voltage supply (e.g., 24vdc) and use a 3-pin regulator to bring the voltage output down.  18 volts is a standard regulator value.  I have a whole stack here, and I'd gladly send you one or two if it didn't mean you waiting a week.  Just note that 3-pin regulators come in 100ma and 1000ma varieties.  While I seriously doubt the pedal would need anything as exhorbitant as a half amp, it is quite possible that a 100ma variety might get warm, so go for the bigger one.  The price difference is likely pennies anyways.
Title: 18V POWER SOURCE? how?
Post by: jimbob on April 16, 2004, 08:09:39 PM
thanks guys!!I doo need a 18v power supply! 12 leds! didnt think about that! Im probl going to go the danelectro route 18v..i assume thats work.
Title: 18V POWER SOURCE? how?
Post by: jimbob on April 16, 2004, 11:02:01 PM
products
ECB-04 Barrel 18V Adapter

Quote18VDC @ 150mA 5% regulated 2.1 mm x 5.5 mm + Barrel negative center

Sale Price: $14.99 Guaranteed Lowest Price - not bad but does it go with it?

i got this as a reply from dunlop:

Thank you for your e-mail. Please note that the part number for the adapter
is ECB004 and it costs $23.97.  You may order direct from Dunlop, however,
we charge full list price plus $6.25 for shipping on all orders

Is ecb-04 and ecb-004 the same?..im thinking so..there is another 18v that is 1.0a--ecb-06

anyway- think ill go w the danelectro --its 11.99

does the "ma" part of it make a difference? 18v 150ma v/s 18v 1.0
Title: 18V POWER SOURCE? how?
Post by: Mark Hammer on April 17, 2004, 12:08:15 AM
I'm no expert, but it stands to reason that if you need , say, 3ma per LED to light 'em up, and a 7-band EQ can often be powered with 10ma from a battery, then 150ma @18v should be sufficient to power this pedal.
Title: 18V POWER SOURCE? how?
Post by: jimbob on April 17, 2004, 06:21:43 PM
I finally bought the  dunlop adapter 18v ..14.00 $not bad really..now i need a damn 15v for my Tonebone british dist effect!!~awsome reviews there --not that i would know..cant try it w out the power source!