Modular Power Supplies


#1

On @tehn’s suggestion kicking off another thread, continuing the discussion from Arc approach:

Anyone have any experiences with the new Intellijel 4U? Any truth to the grounding issues mentioned on muffs?


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#2

I’m very interested in the Intellijel 4U (even with the 1U form factor drama), hopefully someone here has one and can speak to any power issues.


#3

I have never had any issues with Doepfer’s power supplies and busboards, either in Doepfer or DIY cases.
No experience with the others mentioned.


#4

anyone have experience with the synthrotek power supplies?

http://store.synthrotek.com/Eurorack_5A_Power_Supply_System


#5

The only modules I’m aware of that have issues with the Meanwell brick we sell with the TPS80 and TPS30 power supplies are the Rene and Pressure Points. As far as I know the reason is that the design of those modules relies on a connection to earth ground, which that model of Meanwell brick isolates from circuit ground. Strangely enough when I used a TPS80 in my Enclave case I never had a problem with the Rene, so I guess it works in some cases…

Meanwell actually sells a new model of brick that should resolve this issue, but we still have a lot of stock of the other one which is why we’re not selling it yet. You can either buy the new one or one of the Volgen bricks.

I guess in summary, the problem is nothing to do with the power board or case itself, just the switching power brick you use with it. The board itself should work with any 15 - 18 V supply so there are a lot of options out there. The Meanwell were chosen for their good noise performance.


#6

Great info. Thanks!

This, especially:

Cheers! :beers:


#7

Rene/Pressure Points’ sensitivity to Mean Well adapters exists where too much impedance exists between chassis and secondary ground. I’ve experienced this myself with the smaller Mean Well products.

But, not all Mean Well adapters are the same in this respect. With the Intellijel supplies I sell (disclaimer/exclaimer: I sell them, and have many satisfied customers), I mainly ship Mean Well adapters that have these tied together (https://www.trcelectronics.com/View/Mean-Well/GST160A15-R7B.shtml). These adapters also have a locking 4-pin DIN connector and two #16 wires on the output, in my opinion much better than a barrel jack both mechanically and electrically. They cost a bit more, but also allow one to run them well below spec which can contribute to better performance.

So to corroborate and expand a bit on what kisielk says, for best performance AC adapters used to power systems containing some specific modules should have -V connected to AC frame ground (regardless of brand).


#8

Not sure if it’s relevant but I put together a case with a Meanwell RT50b (not of the brick variety) and Synthrotek filtered bus boards. I got small parts off Amazon including an IEC cable, IEC jackplate w/fuse holder, and some molex connectors. Everything works great. One nice benefit is the strong 4A +5v rail - perfect for using with Grids. The whole system cost around $150 for my 7u x 104hp case.


#9

Thought I would resurrect this topic for a general question. I have a Koma Strom power supply, and thinking about upgrading cases from a 3u 84hp to 6u 84hp. The Strom is rated at 1,5A @ +12V / 1,5A @ +5V / 1,0 A @ -12V, which I think is fine, from playing around on ModularGrid.

I was aiming for an unpowered case to keep weight and cost down, and because, well, I already have a PSU! Is the Strom adequate for 6u 84hp? I know that’s a vague question but I don’t want things to run hot, or run out of power if I decide to go for a big digital module like an Erbe-Verb at any point…


#10

I’ve already posted this around but I guess it’s a good idea to post it again:

A couple of things I have learned about PSUs in the years by talking to people who know more than me about it.

The quality of a PSU/busboard system is basically depending on three things:

  • how much current it can deliver without starting to behave in unintended ways
  • how clean the current is in terms of stability and noisiness
  • how big/heavy it is

Most manufacturers will not give you much data on how the PSU actually performs in terms of stability, ripple noise etc. which is a pity. Some PSUs seem kind of not really well designed, I don’t want to make any names because I am not really in the position to support any direct critique with proper technical arguments (I’ll leave that to people who know what they are talking about), but what I want to say is: do some thorough research before buying anything and don’t just look at the current values.
I’d personally go with something where the manufacturer is transparent and honest about how the device performs in real life situations.

Switching PSUs always have ripple noise, many of them have pretty high values. It’s something you might or might not notice, but which can lead to problems of all sorts. Also some switchers require a minimum load or the voltages will be all over the place, so make sure to check that.

Old-school linear PSUs would be the best, they only have the big disadvantage of producing a lot of heat / wasting lots of energy.

There’s many hybrid PSUs that are actually quite good and combine the pros of both switching and linear PSUs. I’d personally always go with that, except if one is really obsessed with having as little noise as possible.

Some filtered busboards are useless because they don’t really filter all that much, so do some thorough research before buying one).

Not really sure about ribbon cables instead of busboards. As far as I can tell they are bad and should be avoided.

Most busboards have a relatively high resistance on the ground bus, which usually leads to noise problems.

Most experts seem to disagree about the specifics, but if you combine the various points of view and add a bit common sense I think you can get pretty far even without being an electronics engineer.

Search for Graham Hinton’s posts on Muff Wiggler. Sure his system is not really ideal for many situations and pretty expensive, but he knows what he’s talking about.

Also worth reading: https://rabidelephant.com/pages/power


#11

@philmaguire the important question is what sort of power demand does your 6U plan require? Provided ModularGrid has data for most or all of your theoretical modules, you should get a pretty good idea from that, but power demands vary greatly depending on module choices.


#12

My current plan (which is very much in flux) is:

893 mA +12V
386 mA -12V
0 mA 5V

According to MG, so should have plenty of wriggle room without things getting too warm!


#13

The general rule of thumb is not to exceed 80 percent of your power supply capacity.


#14

I’d just run the PSU you have, then! I wouldn’t personally expect any issues whatsoever. The lack of a star ground might result in some noise, but I haven’t had discernible issues without star grounding myself.


#15

thanks for the info and advice! the version i have now is the closest i’ve got to 1A, so I think it should be fine. here it is, if anyone is curious:


#16

I frequently wonder how accurate that information is. I often see load that appears to be significantly larger than the stated spec. Unfortunately I’m seeing that in aggregate in my case, and I only know I’m exceeding the supply’s capability because things are not working properly. This approach does not allow me to narrow down the problem in a way that allows me to identify the offender. I resolved it by supplying a lot more power (much more than 20%+) than Modular Grid told me I should have needed to.


#17

fair enough…I believe any inaccuracies would be due to inaccuracies in the power consumption data submitted, which would seem to be the responsibility of the manufacturer. I suppose it might be optimistic to expect every manufacturer to accurately test the max draw of their modules and submit that data given how “wild west” Eurorack is…


#18

There is incentive to under-report draw. Lower draw is more appealing.


#19

Now I can finally share this thing here:

As usual nothing to hide, so you should know that I work for them doing the graphic design.

The thing is a low noise busboard system, which does keep noise at a minimum without having to resort to bulky and heavy solutions like Hinton’s massive bus-bars. What I like about them (though I could be a bit biased) is that they don’t try to hide anything. It’s probably the only power-related product I have seen in eurorack land, which is really fully transparent in terms of specs.

http://www.genusmodu.com/products/libb.html

For now the page has only a general presentation page, but there’s a video online here and more info is coming soon:

and there’s a facebook page as well: https://www.facebook.com/genusmodu/


#20

This looks really nice. Do you know when it will be available?