On racks and "brains and brawn"


I’ve read that with two racks it is suggested to use a “brains and brawn” arrangement, i.e. devices with a transformer on the right rack and devices without a transformer on the left rack. Can anyone please explain the reason? I’ve read some threads but I haven’t found it.

Furthermore, if you have two different racks and one is supposed to be better than the other, would you use the better one for the “brains” or for the “brawn”? I would instinctively say for the “brains” but I wouldn’t able to explain why.

Thanks to everyone who will answer!

Keep all Power Supplies on the right rack where possible and use the best rack for the more sensitive Brain components. It does make a difference. In my system I have the Melco and Phono Stage on the Brain side also due to the large volume of Power Supplies. You have to make it work!

When I split my simrack into brains/brawn it made a significant difference (improvement) to the soundstage.

I went “brains & brawn” a couple of years back and was sceptical at first but I certainly don’t regret it. Yes, it’s another financial outlay but it really does pay off.

Right hand Fraim: Aura/Klimax Radikal 2/300DR PS/Supercap DR

Left hand Fraim: LP12/252/NDX/300 head unit

I too, in my own way have done a similar thing. Big heavy, noisey transformers to the right. Those in the MF right hand box include a pair of 1300 watt jobbies powering a channel each in the left hand box. Which might be why combined, they weigh over 60Kg.

Thank you all for the comments! But why is it better with all the components with a transformer on the right rack? If I arrange them all on the left rack, wouldn’t it be the same?

The cables will usually hang better if you put the ‘brawn’ boxes on the right, and it can keep the heavy duty transformers and their AC power inputs as far away as possible from the sensitive source and preamp.


In the full width boxes I believe the transformers sit to the right inside the case so this maximises distance form sensitive ‘brain’ boxes.

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As well as the transformer being on the right, as mentioned above, it keeps the mains leads on the right, away from the signal leads on the left. If you do it the other way round, the mains and signal leads are much closer together. If you were to have a NAP300 you’d find that the wires are too short to enable you to have the PS on the left.

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Following comments on rack order on other threads from @anon4489532 and others, and some helpfully specific advice from the ever-helpful @Richard.Dane, I changed things around. Getting the Supercap on the right looks worse to me because mine has the brown-not-olive-at-all front, but it has made the (also moved) Superline fractionally quieter. The CDS2 is now on the right of the 52, though if that sounds any better I can’t tell.

Until the day comes when my CDS2 becomes irretrievably dead, I have room for no more boxes and can’t see much net benefit from changing anything else. Of course, when that sad day comes, a small CD transport would leave room to swap the 250 for a 500…


As an update to the update, the 250 is now above the brown-ish Supercap. After the above version, I wondered if getting Superline and Supercap even further apart mattered more than keeping the 250 away from everything.

It turns out that, to my ear, this version is fractionally better, though I’ll try swapping in the next few days or weeks to check that. I am not sure that is in line with theory, but thought it could conceivably be useful to others with a similar collection.

There are HRS rubbery feet under the olive boxes - all marginal but not imagined. However, we tried them under more modern NDX2 and XPS2 and heard literally no benefit on any material at plausible volumes. Perhaps the money Naim has spent on the feet over the last 30 years was not wasted.

Finally, my fiddling about strongly suggests that, if you must have one brawn box in the brain rack to make everything fit, the XPS2 copes far better than any of the olive boxes - CDXPS, Supercap or 250. More successful R&D spend?


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