Here's the link to the rack: ModularGrid Rack

I haven't calculated the individual draw from each row, but I'm sure I can shuffle things around as needed.

Berhinger CP1As are rated for:

+5 VDC @ 0.5 A, pins 11, 12
-12 VDC @ 1 A, pins 1, 2
+12 VDC @ 1 A, pins 9, 10

My rack will draw 1803 ma +12 V and 290 ma at -12 V, which might be too close to maxing out. I'm not too sure how some of this works, whether it's as simple as matching up the power draw to the supply rating or if there's something I'm missing in terms of individual module requirements.

New to the powering side of things. I'm getting to the point where I should power it internally, but I'm using an antique suitcase and I'd rather not cut any more holes in the thing haha.

Can anyone help me out here?


general advice is leave at least 20% (preferably more) headroom - this is too allow for both inaccurate reporting of power draw/capacity and on-rush requirements of some modules that can be significantly higher than the quoted figures

you should aim for at least 2250mA on the +12v rail for these modules and I'd want to use real bus boards not flying ones

these power supplies are 'designed' to power 1 row of 84hp mostly analogue modules - not 140hp with a lot of heavy draw digital modules

or look to slim down a bit - take the moog out (or power it off its own supply in the rack - if you can do that?) and do you really need voltage block and varigate8+ and the bin seq (and the sequencer in the moog) in this size rack? maybe replace 2 of them with another veils (maybe get the new one!) and get rid of the output module (use veils as final stage for speakers/mixers and add an alm hpo if you need headphones - small, inexpensive and very low power)

maybe you could post another question about the other modules - it does not look to be a particularly balanced rack to me

"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia

Utility modules are the dull polish that makes the shiny modules actually shine!!!

sound sources < sound modifiers < modulation sources < utilities


Thanks for the feedback Jim! I might have to move to bus boards at some point, it looks like the CP1As weren't the best choice in any case.

I could get away without the bin seq I think, and I haven't actually pulled the trigger on the voltage block yet -- I would like a bit more CV modulation though and it seems like a good way to both sequence and modulate the rest of the rack. The er301 has tons of internal utility and modulation, including VCAs and so on, it can't send CV out though. You're right though, with the Pulsar in there too the rack has quite a lot of sequencers haha. They're for triggering samples in the ER301 as well as interacting with the visible voice modules.

I'll post another thread to get some feedback on the setup overall though, that's a good idea. Thanks!


Step #1, like Jim said, is to remove the M32 from the cab. It HAS a cab already, and it HAS power already. Eurorack cabs should be for things that DON'T have those already...unless you like making the M32 more expensive than it already is.

Step #2: overspec your power. Jim suggests a 20% overspec on current, while I prefer 1/3rd more than the module complement calls for. The reason is...and yep, this is significant with all of the digital modules...there is a very short interval at power-up when your modules can draw MORE than their rating, and that few milliseconds of overcurrent can cause serious problems for your power supply. And another reason: the more reserve current your power supply has, the cooler it'll run. Heat is very much the enemy of electronic components, and one of the main causes of component failure over time.

Step #3: rethink this. This build is very insufficient in terms of the supporting modules that can make the expensive ones in here already do what they should do. Removing the M32 will give you another 60 hp to play with, and I would suggest that you NOT fill that up with more "sexy" modules. Look instead at the "boring" modules...especially ones that can play with timing, given your sequencer complement. Also, consider carefully whether or not some of the present modules even belong in there, such as the impracticably-huge Fuzz module; could you do that better with a waveshaping module, or by having an outboard fuzzbox and a pedal send/return module?

Try and keep some perspective on what you're doing. These are some expensive modules in there right now, but they're not capable of fulfilling their potential without their support modules. Stop now before you paint yourself into a very costly corner! Avoid being all starry-eyed about these "sexy modules", also...they're really only as worthwhile as the entire build they're part of, and if the build is incapable of using them well, it's going to cost.