let's see...I'll do what I can. boogiebabies and a few others will probably throw in some stuff, especially since I learned everything I know on this forum from them!
Started in 1992. Revisions A and B seem to be prototypes only. Then came revision C and then later revision D around the late 200 serial numbers. These first 500 rectos are the creme of the crop due to these rare circuit board revisions and transformers that were never reproduced. I tested both Rev C and D back to back several times and found the only difference to be that Rev C is brighter, making it more of a "solo" amp. Rev D is a little darker, making it better for rhythm. However, the differences are minimal enough that you can just turn the Presence pot to make them sound the same. The next few years saw revision F. Around 94 or 95, I estimate, revision G, the final revision, was made. The very early rectos had serial loops, small logos, and an attached power cable (which reduces hum). Later on, around 94-95-96, the logos got big, they had parallel loops, and a detached power cable. The tone on the 2channel rectos is a thing of bliss and glory. It is the quintessential recto sound as you would hear it in your head, but even better once you crank it. It is extremely aggressive, but yet incredibly smooth. Under high gain, chords retain incredible clarity in their note's definition. The amps can be very tight when you want them to be (but they are no mark4). The vintage mode is even smoother, reminiscent of the old mark amps lead tones. As each revision progressed, the clean tones got better. Early rectos have horrendous clean tones. It is also worth noting these amps sound great at lower volumes and even better when cranked.
Around 2000-2001, Mesa created the 3channel rectifier--the current offering. As with most things in the music industry, they don't make 'em like they used to. Don't get me wrong--this amp still kicks the a$$ out of most amps out there!! The 3channel amp introduced a new channel and a new mode--Raw. These amps have a much better clean and some great high gain tones. However, they lost a bit of that "mojo." They are not as clear, not as smooth, and not as tight. They sound a little stiff and sterile when trying to play leads and solos. The rhythm stuff is there, but like I said, it lacks the mojo. There's a lot of "beehive fizz" and annoying high frequencies that are difficult to dial out, if not impossible in my experience. I always found myself tweaking knobs. With my 2 channels, they sound perfect flat. Any knob tweaking afterwards is icing on the cake. These amps feature parallel loops and detached cables. To get a good clear sound out of these, you have to really crank them loud.
Then, came the Road King. Version 1 was great, but version 2 is where it's really at! This, IMO, is the amp to get. The cleans are Fender style, you get to pick el34 or 6l6 tubes for each channel; you get two serial loops; and 4 channels. People so far say that the red modern channel is more like the older rectos than the newer stuff. I've only played a version 1 road king so I have no idea...
Along the way of the recto lineage you also had tremoverbs and rectoverbs. I don't know much about the latter, but tremoverbs are ridiculously good amps! They share the same characteristics as the old 2channel rectifiers (indeed because they are a 2channel recto).
You also have single, dual, and triple rectos. Single=50w. Dual=100. Triple=150. I personally think the Dual is the best compromise because you get the features that the Single does not have, and you can drop it down to 50watts to get less headroom. The Triple has great features and lots of headroom, but you can't drop the wattage down because you effectively cut the amps power down by 1/3---there's no 1/3ohm jack in any amp or cab as far as I'm concerned.
Wow...what a long post!! I'm bored man...it's Spring Break. Does that answer most of it??? Anyone else have stuff to add? I hope Mesa doesn't see this post!
As you can see, I am a little biased towards the 2channel rectos. But look at my sig...I own all of 'em. I think I have the right to make a fair comparison...And yes, the tests were all done with flat settings, same tubes, and same guitar, in same room within minutes of each other.
