Im new to modular and planning my system, I´m going DIY for the case.
Im considering either 2 long rows, or 3 shorter.
I was wondering why is there a 168 HP limit in Modular Grid ?
168 is not enough for 2 rows. Is there any technical issue im not aware of?


If I'm understanding you correctly you can add multiple rows to the rack:

Edit => Edit Rack => Rows

unicorns can go bigger - 342hp

I would suggest just starting with a big rack (168hp by 4 rows is more than big enough) and work out what modules you want and what modules you need to support them, then get that checked by experienced modular users - by starting a thread with the url of your public rack for example (I think you can just comment on it) - this often takes several iterations and then once that is done, add a bit of space and power headroom for future expansion - add a further 30% to the power and then find a case or cases that satisfy both the power draw and the hp requirements

this way you can ignore the constraints of the case and power and concentrate on what you actually want to get from the modular and what you need to actually achieve it - it also stops you buying too small a case and then having to go and buy another one in 3 months when you realise that you "need" Maths (for example) and you only have 12hp left

good starter sizes for eurorack cases are 9u * 84hp (Doepfer), 6u * 104p (Tiptop Mantis) or 6 * 140hp (b-company go)

the doepfer and tiptop cases have been around for quite a while and have proven themselves to be solid and reliable cases and power supplies - the b-company one seems popular - I think it's a bit under-powered for the size personally

168 hp was chosen as a limit for the non-Unicorn accounts mainly because the maximum width at that time was 168 hp, as seen in the Doepfer "monster cases". Since then, there's been some firms that have gone larger, most notably ADDAC System and their 197 hp (1 meter) cabs. Most starter cabs are below this width, so the higher width is really more of an "experienced user" requirement...hence why the widths beyond 168 hp are for the Unicorn users. But the Unicorn account is useful ALSO because you can create up to 60 separate builds...with that, you can build up multiple systems and then compare/contrast them to sort out the best approaches to your final desired result.