SPD-20 power plug

[RayPat01]

For those of you who might have a need someday to replace the wall-wart transformer for your SPD-20 (or presumably your SPD-11), here's the specs to match the BOSS BRA-120 unit:

The voltage is 12V AC, rated at 500mA. Any higher amp rating will work as long as the voltage is AC, not DC.

The dimensions of the coaxial barrel power plug are rather large and difficult to locate. However, I was finally able to obtain a suitable replacement from MCM Electronics. It is 3mm on the inside, 6.3mm on the outside, part number 27-860. The cost is less than $1, so the expense of a replacement power supply plus the possible labor of soldering this up to make it work will easily dwarf the plug.

While Radio Shack does not carry the plug, they do carry at least one AC adapter that appears to fit the voltage requirements. It is part number 273-1631 and is a switchable voltage unit. The coax power plug is one of the more common types to fit answering machines, etc so you'll need to either wire up an adapter cord with the MCM plug on one end (my recommendation), or hack off the plug and solder the MCM plug right on to the wire. Regrettably, while MCM carries a rather large selection of replacement DC adapters they do not carry any AC units that I could spot from the last major catalog.

In case anyone was wondering, nothing's wrong with my original adapter; I just needed a (much) longer cord than the 6' that is supplied with the Roland adapter. My SPD-20 is mounted on the left side of my rack, the power strip where everything's plugged in is near the rear right tube. I was not able to locate a female coax connector to wire up an extension cable, nor did I want to put an extension cord and have the wallwart mounted on the rack.

This should work for any other device that uses this particular adapter. Hope this turns out to be useful to someone out there.

[CAH2112]

I know what you mean. I just cut mine and added like 6 feet to my cord. Don't you think it's a shame that they don't build the transformer in like the TD-10. I mean really, how hard could it be?

[RayPat01]

transformer inside SPD pad

Actually, pretty hard. I've had mine open and I can safely say that it would have been pretty difficult to squeeze something like that in there. Personally, I'm impressed that they were able to do so on the TD-10.

While we're talking about the SPD pads, here's another good tidbit: the battery that powers the memory for your custom patches is the same type of coin battery that powers the CMOS in most modern PCs: a CR2032 lithium. If you undo enough Philips-type screws, you can replace this yourself instead of having a music store do so at an hour's labor. Unlike your computer, you want to make sure that you keep power to the unit while doing this or you will loose your patches. Again, this applies to the SPD-20 but I assume that the SPD-11 (and possibly the 8 and 6) use the same battery.

This coin battery is $3 at Rat Shack, $1-2 at most mail order vendors, and as low at 50c when purchased in bulk quantities from eBay vendors.

[chamberlainwannabe]

I asked my guitar teacher about changing the lithium battery when/if it wore out on my gt-3 guitar processor and he said you have to take it to the store because it's a dangerous process. So was he just feeding me a line of crap?

[RayPat01]

GT-3 guitar processer battery

Your teacher is advising you to have a professional do this because a professional would presumably know how to 1) work around the delicate electronics to not damage the unit, and 2) avoid getting shocked by the high voltage that could be present.

Never having seen one before, it really depends on whether or not the power supply is built in. If it is, there is household current coming in to it. This is the voltage that can deliver a large jolt that can injure pretty badly.

If it uses a transformer outside the box (such as a wall-wart), you would have no more than usually 20V going in to it.

I am fairly confident in saying that if you've ever had a modern piece of electronic equipment apart (such a computer or stereo unit), you can probably change this battery without too much trouble provided you know what to look for. If by chance it happens to use the same lithium coin battery mentioned in my previous posts, anybody who works on computers can do it.

[Boingo]

So all of the difficulty/caution revolves around doing this with the power supply on. If you have a memory card or other type backup, I assume the average bear can change this out with no major concerns since the unit can be unplugged, correct?

I have yet to see a post from someone who got a low battery message. Anyone got to this point yet?

[drummerdude01]

Great info

Excellent & informative post! Thanks!

ddude

[tristelune]

Thank you!!

Wow, 7 years later this post really helped me today! Thank you very much!
My power plug was lost during a recent gig and I had a pretty hard time trying to find a replacement. A guy at an electronic store told me the inside diameter was 3.5mm so I would just like to ask if you had any problems with your 3.0mm. If not, I will probably buy the 3.0 (does 0.5mm is enough to make a huge difference?).

Again, thank you very much!!
PP

[BarT]

Wow, 7 years later this post really helped me today! Thank you very much!
My power plug was lost during a recent gig and I had a pretty hard time trying to find a replacement. A guy at an electronic store told me the inside diameter was 3.5mm so I would just like to ask if you had any problems with your 3.0mm. If not, I will probably buy the 3.0 (does 0.5mm is enough to make a huge difference?).

Again, thank you very much!!
PP

You can get the genuine article from Roland for a reasonable price:

AC Power Adapter (BRA-120) - 12449622, USD$ 32.00 at Roland US Store

Bruce

[J-Blues]