Does the MP1 need an open space above or can it be mount in the top space of a furniture grade studio rack with approximately 1/2 inch of clearance above? If I build a slant, then there will be plenty of clearance but I'm undecided about slant vs straight.
I wouldn't say it needs and open slot. It definitely wouldn't hurt. I have mine in a Gator 8 slot road case, it is in the second slot from the bottom with a Marshall JMP1 under it and my Carving power amp above it. I have no heat issues and it's on for 4 to 6 hours at a time. Buy the way my rack is full and I have and eq and hush unit in the back. Hope this helps.
Hey Metropolis, tubes need a little air to "keep cool" if you have the space, it's not a "bad" idea to make some room. I ran my MP1 and now MP2 at the very top of my SKB 8RU rack (which has some space above (where tube heat will vent from top slats)) and put power amp at the bottom (well now separate Carvin TS100 in it's own 2 RU rack), digital gadgets in between. MP2s get quite hot and need to breathe MP1s not quite as bad but same issue. Hey heat rises, digital gadgets don't add that much heat, put preamp up top, keep very hot power amps as far as is practicable....
I do not vent mine. If you can get a very small gap between units to let a little air through you will be okay. I have left my gear on all week before and it was fine. I was recording and didn't want to touch anything. That may seem a little over the top but when you lock the tone in I didn't want to touch anything. If your rack allows the space then go for it. I wouldn't spend the money on a rack for extra space to let it air out. Just my opinion of experience hauling a monster rack around in my younger days.