PSU for GC v1.00?

Q & A for building and interfacing your rack gear with Ground Control Pro and GCX-based systems.
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Joined: Fri Jul 17, 2009 11:29 am

PSU for GC v1.00?

Post by Piplodocus » Fri Jul 17, 2009 11:57 am


I have an old GC (un-pro) v1.00 from '91 that's been collecting dust in my attic, and I was thinking of using it to control Ableton Live. However, last few times I've been using it I ran it off phantom power from my amp, but now can't from my MIDI interface (no phantom), and I don't have a 9v AC PSU. I don't want to spend the money for another one as I'm broke, but I have some other PSUs floating about. Can I use one of them?

After having a look-see inside it appears the first components are bridge rectifiers made out of discrete diodes. Does this mean I can use a decent quality DC PSU instead, if the first thing it does is convert the AC to DC?

If so what voltage DC PSU should I use? 9V? 12V? (because of RMS conversion?) 6.5V-ish? (because it's half that relative to 0v)? What current? Or is this not possible at all? (I notice it's a 5v regulator in it spec'ed at 1A max output)

Also, will a firmware upgrade mean I have to press and hold the setup button to go into config mode as I seem to remember from quite a while ago, it was a little too easy to go into config mode during a gig?

What other mods does it need to make it v2 compatible (it was mentioned in another post that it needed something other than just the chip)? I may/may not just buy another controller at some point instead of upgrading it, but it'd be pretty handy in the shorter term as I'm skint at the mo'. :(

Also, what does the 2k/8k jumper do? I assume it's why the chip in the nearby holder has 4 less pins!



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Joined: Mon Jul 20, 2009 7:45 am

Re: PSU for GC v1.00?

Post by ElmerJFudd » Mon Jul 20, 2009 7:52 am

I have the same unit and e-mailed Voodoo Labs over the weekend.

However, I don't mind picking up a replacement PSU if need be.
What is the rating for the PSU for the Ground Control?
9V yes, but what MA rating?
Also, am I right in assuming that its OK if the MA rating is equal or higher, its lower where there would be issues?

And of course, is it possible to do a firmware update on the unit to V2?
Normally, I'd say this was done over SYSEX, but the GC has no MIDI IN.


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Re: PSU for GC v1.00?

Post by JohnClark » Mon Jul 20, 2009 12:10 pm

The power supply for the original Ground Control was 9VAC @500mA(min). It will accept AC or DC. I have no real data on exact cut offs but 9VDC @500mA(min) should work. 12 volt supplies may start overheating the 5 volt regulator so I would avoid using them.

v2 software will in fact add the "safety" delay to avoid accidentally going in to Program Devices mode, and will add features like Bank 4 Mode as well as the ability to add the expanded memory. The expanded memory will give more preset locations when used in the Bank 10 mode as well as add the capability of controlling up to four GCX switchers. The jumper is set to match the memory chip installed. A v1.00 Ground Control will have to come here for some various component changes to the board in order to accept any v2 upgrade. Any 1.01 or higher Original Ground Control can be user upgraded by installing a new chip.
---------==Voodoo Lab Magician & Tech==---------

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