I've had three main guitar rigs since I started playing guitar as a teenager. Here is my rig circa 1991-1992, when I was the rhythm guitarist in the seminal Hayward band, Mystic Rage. I no longer have any of this rig - I sold the lot to StickyC several years ago.
I bought the cab from another guitarist in the practice studio. I think I paid $100 for it. I soon blew up all of the speakers by using a high-powered PA amp instead of a proper guitar head. (Did you know that guitar speakers can make a psychedelic blue smoke?) My replacement speaker set was a Frankenstein combo of two Eminence speakers gifted to me from my band mates, one 70W Celestion I bought from a catalog, and one "mystery speaker" I found at a used music equipment store in Berkeley. The Crate logo fell off at a gig somewhere, so I replaced it with a logo from a Heineken store display. Everyone always asked where I got a Heineken speaker cab. Of course, someone eventually stole the Heineken logo.
I likely bought the Crate G600 used from Weenboy. At 60W, it just barely played loud enough along side Pete's drums. A solid-state head, it was extremely durable and… beverage-proof. The dirty channel was pretty nice, but I preferred the clean channel with the excellent Presence control and spring reverb.
The TwinTube was an overlooked jewel of a rack preamp that I used in the effects loop of the G600's clean channel. Not only did it have two 12AX7 tubes, it also had some really versatile effects tweaking. In particular, you could set two graphical EQs, one before the distortion, and one after. You could also set two compressors, again before and after distortion. Those settings were key in getting a huge Metallica-ish tone out of some low-budget equipment. Two things started to bother me with the TwinTube: 1) I spent too much time tweaking and programming the thing instead of playing my guitar, and 2) It was missing some high end. It was only rated up to 16Khz, and I'm sure it dropped of a little before that. At the time, I felt the missing high-end caused a lack of "crispiness" and clarity, though after playing metal for all those years, hearing anything at all above 16Khz is a rare treat.
I bought a few other components for this rig that I ended up never using.
I thought the DSP-256XL would add the high-end clarity I was looking for in the TwinTube, but instead, it sounded a bit dark. I'm pretty sure I could have corrected that, but programming the thing took hours, so I gave up.
The MicroCab was sold as a speaker simulator that you could use for recording at low volumes without a microphone. I never got serious about recording, and thus never used this rack.
Not sure how many times this Ibanez EX changed hands between StickyC and Don before I got a hold of it. Call it a lack of patience, but I could never get this guitar to stay in tune with that blasted Floyd Rose. I've never had a guitar with a Floyd since. I did put a sweet DiMarzio FRED pickup in this, but alas, never played the thing. The flight case was very nice.