So I've been thinking what exactly is the purpose of the tilted speakers in the cabinet design for the Sunn Beta Lead. I never owned one, and don't know if it serves any auditory purposes or is it just efficiency?
http://www.seymourduncan.com/forum/attachment.php?attachmentid=40716&d=1364930312

Hey, does anyone know good books on principles of acoustics of speaker cabinets and particular designs of speaker cabinets? Maybe also about the particularities of resonance and of certain woods?

Hello! I'm new to the forum and this is my first post. I'm 27 years old and decided my new hobby is going to be building solid-state amplifiers. 
I already got a project I'm working on, but I have no idea where to start. Recently, the rotating speakers of my cherished Yamaha RA-100 broke down. I use a very heavy fuzz on guitar, so I loved this amp because it is very clean. In any case, my Big Muff worked really well on it, it had a very smooth fuzzy sound which was amazing. The rest of the amp was pretty much hunky-dory, and since you can't really find replacement rotating speakers anywhere and I didn't really feel like dragging this gigantic amp around for gigs anyway, I decided I wanted to turn the combo into a head amp. How hard could it be?
Well, as someone who is a complete novice to electronics, pretty hard. So after a long search on the webs, I actually manage to find all the schematics for the Yamaha RA-100. But I still haven't got a single clue on where to start. I'm not sure which parts I can leave out, because they're parts of the rotating speakers circuitry and I don't know what parts I need to get it running. So I dismantled the whole thing and it's pretty much collecting dust right now.
Could anybody help me out please?