Saw this 6U by 84hp Eurorack case used for sale. Immediate impulse buy! This photo shows my modification to replace the included Meanwell power supply with one of my old Power One analog supplies.
Meanwell supply
On testing the Meanwell supply I found three issues. #1 – the 12V output was yielding only 11.5V with no load. #2 – The 5V output was competing with a 7805 regulator on the distribution board. They were connected right together. I disconnected the Meanwell 5V before testing and found that the onboard regulator was working OK, drawing from the +12V input. #3 – The -12V current rating of the Meanwell was only 500ma. So I decided to replace the supply. But I will reuse the cover shield.
Another recap job
I kept the four old Power One supplies when redoing the power for my MOTM system a while back. I refurbished one of them by replacing all the electrolytic capacitors. I had bought enough capacitors when I did the MOTM job. Every electrolytic cap in the Power One was replaced with a new one with exactly the same make (Nichicon) and specs.
These supplies can work at +/-12V or +/-15V. I added back the jumpers to return it to 12 volt outputs.
The HAA15-0.8-A can deliver 1A of both +12V and -12V. Calls for a 0.75A AC line fuse. I used 0.8A, same that was used when powering MOTM modules.
Note that the earth ground from the AC inlet gets connected to the supply chassis, the aluminum case, and also to the power supply zero volt line (black). They’re all tied together at the chassis (upper left in photo).
It isn’t much deeper than the Meanwell. Still plenty of room above for Eurorack modules. The Meanwell shield fits quite well, though it did require some cutting and bending. I made a small bracket with a piece of it I cut off to secure one end. The other end (lower right in pic) screws into a standoff mounted in a very conveniently located existing hole in the Power One chassis. It’s not so much for shielding, as to prevent screws and such from falling into the supply. (I’ll install modules with the power off, of course.)
Now for a rack frame
I discovered that you can buy desktop rack frames. I found one on Amazon for $50. It’s 4U height and I can put only two screws to mount the Eurorack case, but it’s enough.
Update: Photo shows the first set of modules loaded. Transferred all of the modules in the Logic, Dividers, Logic and Switches small case and added more. Here I now have:
- Four tap tempo clock generators
- Ten clock dividers
- Four clock multipliers
- Three logic modules
- Eight random pulses (Pithoprakta)
- Three switch modules
- One quad LFO
- L-1 triple passive attenuator
- L-1 Quad VC Mixer
Current draw (from Modular Grid): 500ma @ +12V, 230ma @ -12V
