First of all, I'll apologize once again right up front for another long, rambling post. I'm basically trying to understand exactly what happens to the signal when I plug it into a bass amp that gives it the sound of that particular amp. But I need to provide some background information, first, before asking my questions. So, here goes: Many years ago, when I was doing quite a bit of gigging, I decided that I needed a "big concert rig" for larger venues. At the time, I was getting some gigs at some very, very large rooms along with the occasional outdoor gig. I wanted top quality stuff, with plenty of power. So, I went out and purchased a Crest power amp and then started looking for a preamp for it. The way I went about this was to first think about what actually happens to the signal when it goes into a bass preamp, and then try to figure out what I needed to give me control over that particular characteristic of the signal. The first thing that came to mind is that a preamp gives you tone knobs that allow you to control the various frequencies of the bass signal. I also understood that, whether or not a bass amp has an actual "compressor" built in, you usually get a certain amount of compression from the bass amp itself. So, I ended up buying a Rane five-band parametric equalizer and a Rane DC 24, which is a stereo comp/limiter/gate. Oh, actually, there was one more component to my "bass preamp," at that point. That would be my cheap wireless transmitter which, although it's pretty noisy, it also is capable of boosting the raw signal from the bass guitar up to a line level that would properly drive the Rane processors. I knew that the gate (expander) on the DC 24 could take out the "hiss" from the cheap wireless unit, farther down the signal chain. So, the signal from the bass was broadcast via the wireless transmitter to the receiver, then on to the parametric eq, then the DC 24, then on to the Crest power amp, which was mounted in a separate rack (along with a stereo 31 band eq for when it's being used for PA duties). This would then drive either one or two cabinets w/ JBL E140's, depending on how much power I needed. As far as I could figure, I now had a rig that could replicate the sound of "every bass amp ever made." I could recreate the frequency response curve of any bass amp with the parametric eq, and then duplicate the exact amount of compression needed with the comp/limiter. I played around with the system, first, at low volume levels and then started to take it out to gigs. And, well.... Let's just say that it didn't quite live up to my expectations. First of all, the tone not really doing anything for me. Furthermore, not only did it NOT seem capable of imitating the sound of "every bass amp ever made," the simple, honest truth was that it didn't really even sound like ANY bass amp ever made. Instead, no matter how much I tweaked the knobs, it just sounded like I had simply plugged my bass into the board with a passive DI and then cranked it up to extremely loud levels. Waaaay too clean. While this might be the ideal rig for those of you who like an ultra-"hi-fi" sound for your bass, it just wasn't working for me. Nevertheless, I still used this system whenever I needed more power than my old faithful Yamaha B100 (120 watts) could provide. It was the only thing I had with enough power. Never was pleased with the sound, though. Then, I dropped out of the music scene. Years went by. During that time, I often wondered why this plan didn't work. Since the signal sounded too clean and "sterile," it seemed obvious that what was missing from the equation was distortion. Most bass amps, even the relatively "clean" ones, probably add at least a little bit of distortion. O.K. That makes sense to me. So, I picked up a Sansamp PSA-1, and added that to the preamp rack. The PSA-1 is primarily designed for guitar, but certainly allows such a fanatical degree of control over the distortion parameter, that it would surely satisfy just about any "control freak" bass player or guitar player. Actually, it almost has TOO MUCH control. I almost wish I had gotten the RBI, which is half the price, but is much simpler and is much more "user friendly" for bass players. Nevertheless, I can certainly say that I now have LOTS of control over the distortion parameter. Of all the knobs on the front panel, one is a master volume which merely sets the overall level, and two more knobs are tone controls (active, shelving-type bass and treble controls). All the other knobs on the front panel relate to different ways to induce distortion into the signal. You can dial in different amounts of "pre-amp distortion," and "power amp distortion." Other knobs have strange names like "crunch" and "buzz" which, apparently, let you dial in different amounts of distortion at different frequencies. It's my understanding that the distortion is provided via FET technology (i.e. Field Effect Transistors) to simulate "tube distortion." While I understand that FET's will never satisfy a "tube purist," my personal impression is that, in a full-volume gig setting, it's "close enough for rock and roll." Not only does it give you a pretty darn good approximation of what tube distortion really sounds like, it even behaves much like a vacume tube. (In particular, this preamp is very sensitive to the dynamics of your playing, unlike the pre's that use digital technology to simulate tube amps, such as the Pod by Line 6.) Now, I'm not trying to start a debate about whether or not you believe that FET technology "really sounds like vacume tubes" or not. Nor is this intended to be one of those "is this rig is better or worse than such-and-such rig" threads. I have assembled this system based upon the following hypotheses: 1) Every bass preamp does something to the signal that makes it sound the way that it sounds. 2) If you can figure out what gets altered about the signal within the preamp and modify the signal in the exact same way, you can replicate the sound of that bass amp. From these hypotheses, I decided that, by assembling components which allow me to alter all of the various parameters of a bass signal at will, I could create an "ultimate bass rig" that could recreate the sound of any and all other bass amps. It seems to me that, with the addition of the Sansamp, I have succeeded at this -- theoretically, at least. However, as the earlier version of this rig demonstrated, there is sometimes a difference between theory and the reality of a live gig situation. What I want to ask TalkBass'ers is: First of all, is my basic logic sound, or is it flawed in some way that I'm not seeing? Have I finally succeeded in gaining control over ALL the different parameters that cause a particular bass amp to sound a certain way? Why or why not? If you don't think so, then what is it, specifically, about the bass signal that still can't be manipulated with this setup? In other words, have I finally achieved my "holy grail" of having a bass system that can do a reasonable imitation of any bass amp I could conceivably want to use, just by finding the right settings for the knobs on the various processors? I would appreciate any comments you might have on this subject, and I apologize once again for the long post.