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"Every Bass Amp Ever Made" (in two racks)

Discussion in 'Amps and Cabs [BG]' started by BLU Dragon, Jun 8, 2002.

  1. 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.
  2. JimM


    Jan 13, 2000
    Northern California
    Interesting subject...

    I think of tone controls,whether they are parametric or graphic or whatever,well let me put it this way...putting a "bass"knob on an amp with little power or with a poorly designed power section,or a low frequency slider at 60 hz.on the same amp is like putting a speedometer that goes to 300 miles per hour on a volkswagen.

    I think it's almost like human voices.I can mimic different people's speach but its still obvious that its me,on the other hand guys like Robin Williams and Mel Blanc can totally disguise thier voices.Same,I think with tubes and transistors,they have a voice of their own and no amount of capacitors can change that.

    but that's my ignorant two cents,looking forward to what others say about this.
  3. JoelEoM


    Mar 11, 2002
    Lancaster, PA
    i think speakers come into play as well. take a vintage svt. what cab is usually under that head? an svt810 of course....which is part of what gives you that vintage svt grind. cabs arent everything of course...
  4. Oh, absolutely. I understand that you can't fully replicate the sound of somebody else's bass rig, unless you also have the same speaker cabinet and the same bass, of course. I understand that, if I can replicate the sound of an SVT ampifier, for example (and there is pretty reasonable approximation of an SVT as one of the presets in the Sansamp), then it still won't sound like a classic SVT rig if I play it through my JBL 15's.

    For right now, I'm simply trying to increase my understanding of what happens specifically to the signal once it enters the bass head.
  5. submelodic


    Feb 7, 2002
    Seattle, WA
    This is an interesting subject. I'm no expert, but I think Psycho Bass Guy is on the mark. An analog signal is affected by every electronic component it passes through. Each component affects the harmonics of that signal, which changes its audible characteristics (colors the sound). I would guess that to have "every amp" in one unit would require having the identical electronics of every unit available to be switched in or out. But maybe the switching itself would have an effect...
  6. Wxp4759cb


    Nov 23, 2000
    Kansas City, MO
    Get your self a Peavey BAM head, a large power amp, and a couple EA 2x10s.

    I also think with what your trying to do the tubes make a difference. Preamp tubes are going to add some extra harmonics and natural tube compression. Maybe adding one of those Aguilar Tube DIs to your setup would help with that.
  7. The guitar guys and hi-fi audiophiles have been down this road for years, and there's a huge amount of research and commentary on the subject...

    Suffice to say that the things that affect sound go far beyond the simple frequency EQ controls we get on our electronics. Some of it's on purpose, some of it's accidental, and some is still a mystery. It's almost impossible to get the real sound without copying the circuit and components exactly. Even if it measures the same, it won't sound the same. Sound is more than frequency; it has attack, delay, and many other nuances that are hard to measure but easy to hear. All are affected by every part of the signal chain. And every mfr’s signal chain is different.

    Why? Because in electronics, there are many ways of doing the same thing. Each circuit has a design, and each design has it’s own affect on the sound, Each component in the chain has a mfr, and that mfr has a particular way they do things; cheap, expensive, analog, digital, different materials (mica, paper, electrolytic, poly just for capacitors), and the materials and process also affect the sound. Even something as simple as a power supply has variables like different number of windings, different core material, the paper between the windings, etc., just like a pickup sounds different for the same reasons. All of this affects the sound quality and is discernable to the knowledgeable listener. Sometimes the very simplicity and use of cheap components (resistors with wide tolerances, etc.) leads to unusual combinations outside the original design intent on the production line, and some of these sound wonderful. Even the designers sometimes get fooled.

    Music is very subjective, like art, but many designers are logical engineers, and have historically often tried to create clean and neutral circuits. But certain coloration is actually desirable, otherwise we wouldn’t care about types of fingerboards, body and neck wood and construction, string types, etc. That’s why so much gear with great specs doesn’t move us. The best designers are those that understand real-world playing issues and incorporate that in the product. It doesn’t have to be logical, it just has to work.

    For instance, when Vox wanted to re-issue the classic AC30 amp, they auditioned many samples of the "best" vintage ones from the 1960’s. Then they went out and found as many of the original component mfrs as possible, built it as close as practical to the old way, and the sound is VERY close to the original. But anything short of this multi-year research effort did not sound the same. This applied to transformers and other components as well as speakers. (This is not hearsay- I have 4 of the Vox JMI originals, have been present during a/b shootouts by pros, and have talked to the people involved at Vox/Marshall in the reissue project). Each component most definitely colors the sound in some way, and when the blend is good, that piece of gear gets a legendary reputation. The digital emulators can get close, but are still not there (yet??)…

    So, your quest to “assemble components which allow me to alter all of the various parameters of a bass signal at will” and “create an "ultimate bass rig" that could recreate the sound of any and all other bass amps” will be tough. Unless the challenge is fun, maybe it’s more practical to find a few sounds you do like, and get those. Or, do like a lot of us, and have several amps to suit different purposes. But that leads to something called “GAS” pains…and that’s a whole ‘nuther subject….

    Hope this has at least been thought provoking…

  8. Practical? You mean this is supposed to be practical???? :eek: Well, guess I'm busted, then. I mean, after all, I'm chasing a mythical creature (the "ultimate bass amp"). How practical can that be?

    Yeah, you're absolutely right, of course. I would be far more practical to find a few bass sounds that I really like (or one that I really, really like) and stick with that. And, in all honesty, that sound would probably be nothing more exotic than a good ole SVT. To my ears, that's what a bass amp is "supposed to sound like." (Although, I also like the sound of my Yamaha B100 and the SWR Bassic Black is O.K., too.) I actually have an SVT III (it later evolved into the SVT 3Pro) and, as long as it continues to reliably drive both my cabs at 350 watts into four ohms, I'm probably home free, at least until I need more power than that. Then, the component system seems to be capable of a decent "emulation" of the SVT sound, even before I tweek any of the knobs on the Sansamp or take the Rane processors out of bipass mode. So, the simple truth is that, for all "practical" purposes, I'm probably already covered for acceptable bass amp sounds for a variety of gigging situations. I don't need to tweek anything.

    I started this thread for a few simple reasons. First, I wanted to increase my understanding of what happens to the signal, electronically, when I send it into a bass preamp. Secondly, while I like to hang out here and read all the posts, I was getting kind of bored with the "how do you like this rig" kinds of posts. So, I thought I'd try something a little different. Just for fun.

    Thanks for participating in the discussion, and in my mythical quest.
  9. I think a company should make something like Fender's Cyber Twin for the bass. I have played my uncle's friend's Cyber Twin and I must say I was amazed. It could do a really good job of recreating a sound of an old Marshall stack or any of the other amps are on that head. Any one agree? Or am I just being stupid and this post was a waste?
  10. This is definately a very interesting subject. I can imagine that your rig is very versatile, and I see no flaw in your logic. Except for speakers, which was already discussed. And of course, you can only approximate the sound of another rig. The point, and the question is: do you like the way it sounds?
  11. BLU D.-
    It is a good subject, you're right. I think we're all on the same road somewhere... Sometimes I think the part I like best is that it's NOT practical!

    I haven't heard the Cyber Twin more than a few minutes, but some of the modeling amps come amazingly close to their goals of offering the different amp sounds. It's only if you've had a Marshall stack flapping your pants legs, or played a 1964 AC30 Top Boost, or pre-CBS Twin, or whatever, that you'd notice the difference. For bass, you can get an effects unit that also models different bass amps & cabs for a few hundred dollars. I got a Digitech BP200 recently; fun to play with, and some good sounds too. There are others from Line 6, Pandora, etc.

    The problem with cool vintage stuff is, it spoils you! Then you have to decide if you can afford a lot of cranky, expensive cool stuff you don't really use much, or just get something that sounds close and is a whole lot simpler (and cheaper). Seems like we're all moving back & forth somewhere on that line. Myself, I like to try stuff firsthand, then decide if it's worth keeping it or a simpler substitute will do. So I respect both choices. It's fun, you can let your own ears decide, and you learn a lot...

  12. Fuzzbass

    Fuzzbass P5 with overdrive Gold Supporting Member

    I love the Rane DC-24! I use it as a split-band compressor, crossover point @200Hz. What I want to mention, though, is that it has +4dBu/-10dBu input gain trim switches on the rear. If you set the switches to -10, you get a 12dB boost which allows the unit to function with instrument-level signals. You could run into the compressor first and then the EQ. One advantage is that you'll be able to adjust your EQ without messing up your compressor settings.

    In fact that's pretty much how I run my signal nowadays: first to a SansAmp BassDriver DI and then to the Rane DC-24 at the -10dBu setting. From there I go to a tc electronic 1140 four-band parametric equalizer, then to my power amp. I once used the tc parametric for the very reason you chose your Rane parametric, but same as you, I realized that tone was more than just EQ. My favorite amp of all time is the vintage Ampeg SVT, and of course my solid state rig was not designed to provide the rich harmonic content of the SVT tube head. I would never say that the SansAmp is a perfect SVT copy, but as you say above, Tech21 products do tube emulation very well.

    P.S. I'm a "set it and forget it" guy. Lately I've been finding the "sweet spot" on my SABDDI, and using the parametric only when room acoustics give me difficulty.
  13. Well, actually, I can't answer that, yet. I have not had an opportunity to use this complete system on a live gig, yet. I have played around with the full preamp rack (since adding the Sansamp) while it was plugged into the effects return jack of other bass amps (usually my SWR Bassic Black). However, I did not have the power amp available. In fact, I just recently retrieved the Crest power amp, which had been setting in a warehouse for about a decade. (I had to spray all the dust out with compressed air before I could use it.) That amp has since been called into duty as a PA amp for my band, so I will have to buy another power amp before I can actually hook everything up for the "big rig" and put it to use in a live gig setting. The band I'm currently with hasn't played anywhere yet where I need that much power, so I've got a little time to shop for a new power amp. (QSC amps are a strong contender at this point.) So, all this is strictly a theoretical discussion for the time being, but will be put to the test out in the "real world" as soon as the right gig comes along, and as soon as I can get another power amp (or the band buys another power amp for the PA so I can get my Crest back).

    My initial impressions of the Sansamp are sort of mixed. A lot of the sounds are pretty nice. They seem pretty credible, too. You can easily tell by listening (i.e. without looking at the manual) that the SVT patch is obviously an SVT, the Bassman is obviously a Bassman, etc... It's got an absolutely AMAZING imitation of Chris Squire's rig. I don't own a Rick, but tried the box out at the store with a Jazz with fresh strings, which was close enough. The Sansamp absolutely nailed it.

    However, there's a world of difference between finding sounds that sound good in the privacy of my own home (or the showroom floor) and in a full-volume, live band situation. When I first took the preamp rig to a rehearsal (feeding the power amp and speakers from the SWR Bassic Black) I walked in there with what I thought were a bunch of "killer custom presets" that I had programmed in. But some of the patches that I really liked at very soft levels fell apart when I cranked 'em up and tried them with the band.

    So, I'll have to get it out into a live gig before I can give it a final ruling as far as tone. (I'm dying to A/B the SVT patch on the Sansamp with my actual SVT III during a live gig and see how different they sound.)

    The other thing I don't like is that it's really not very user-friendly. Even when you know what the knobs do, you don't necessarily just automatically know how to get a certain sound you're looking for. (I mean, for example, just how much "buzz" and "crunch" would you dial in if you were trying to simulate an SVT from scratch?) Just as we've been talking about "practical solutions" vs. "theoretical solutions" here in this thread. This devise is a good example of that. I bought the PSA-1 for reasons that made perfect sense for the total concept of my "ultimate bass rig" (i.e. get complete control over every parameter of your tone). I was looking for control over the distortion parameter and -- buddy, I'm tellin' 'ya -- I've sure got lots of control over the distortion parameter, now. However, now that I own it, the RBI would be a lot simpler to use on a gig. And it's half the price.
  14. Munjibunga

    Munjibunga Total Hyper-Elite Member Gold Supporting Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    Man, these are some of the most articulate, thoughtful and sensible responses I have ever seen in a thread. Congratulations to all of you. Great topic! The grammar and spelling are even good.

    I feel so stupid.
  15. Jeff Moote

    Jeff Moote Supporting Member

    Oct 11, 2001
    Beamsville, ON, Canada
    Don't. I was thinking the same thing.
  16. Nobody should feel stupid! Everybody contributes something unique here.

    Munji, some things you've said here have made me go back and re-evaluate. Plus you make me laugh!

  17. Not bad for a bunch of bass players, is that what you guys are saying? :D

    Seriously though, I've always found these boards to be exeptionally civil and well-mannered. Very well moderated. Not a bunch of flaming. Minimal foul language (in keeping with the board rules.) And, lots of expertise on a variety of issues, including some fairly complex and technical ones.

    A very good board. Cool place to hang out.
  18. Yeah, that's basically what I'm doing, now. Current signal chain is: Sansamp to parametric to compressor. You're probably right about putting the parametric after the compressor. However, like you, I really find very little need for the eq. It's usually bipassed, making it's position in the chain irrelevant. I have considered putting one channel of the DC24 into the effects loop, but decided, instead to run the two channels in series. That way, I can have one channel set for my Jazz bass, and another set for the five string, and just engage the one I want for whichever bass I'm using. I've never had any success using it as a multi-band compressor. I just don't think the crossover works properly. (Seems to work fine, though, when I'm outputting to two separate amps. Never could figure this out.)

    So, it's basically just the Sansamp, with just a wee bit of compression (I think with every compressor I've ever tried, I personally ended up finding the "sweet spot" at somewhere between 1.2:1 and 1.5:1.)
  19. Fuzzbass

    Fuzzbass P5 with overdrive Gold Supporting Member

    Very cool idea. Right now I play just one bass each gig (I bring a second as backup only) but if that ever changes I'll try this.

    I bought my DC-24 used... no manual. But (in case you weren't aware) the Rane website not only offers a downloadable manual, it has other cool docs on the DC-24 specifically and compression in general (all in .PDF format). You can find 'em here:

    But hey, you might decide to stick with your current serial setup even if you get the split-band compression working right.
  20. Nick man

    Nick man

    Apr 7, 2002
    Tampa Bay
    I think Psycho Bass Guy was right on the mark when he mentioned that a major flaw is that each stage in an amp colors the sound, and a major factor in how an amp sound is where in the series the sound is colored a certain way.

    I have noticed that when EQing, I like to boost and cut certain frequencies in different orders.

    The same, Im sure goes with the amplifiers natrual frequency curve. Im sure that some frequecies are boosted and cut at the imput stage, and that some are boosted and cut at the compression, and then when it gets to the equalizer you boost and cut some, and then when it reaches the power amp, again some are boosted and cut.

    Maybe this will clear up what im trying to say a little better. If the frequencies in the 350Hz range are boosted at the input stage, then they will be compressed more than frequencies in the 1kHz range that you boosted at the EQ section.

    Im sorry if throught all this I made no sense.


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