12-String Bass Rig Theory:
The Guitar Side

The 12-string bass is theoretically 2/3rds guitar, and the guitar amp plays a very important role in the composition of a 12-string bass rig. There are certain things to remember when playing any type of bass through a guitar amp, but we will cover those in Part 3. In this section we will only be dealing with different types of amp options and what they have to offer the 12.

The guitar amp is the least understood part of the set-up to most 12-string bassists. Perhaps the best way to approach it is as an afterthought to the bass amp, almost as an effect rather than primary amplification. The main elements that the guitar amp brings to the table are distortion, highs and mids. When trying out guitar amps with a 12-string bass never try to get that big, fat low-end from it because it's just not there and you may blow the speakers trying. Remember, you will be blending this with a bass amp that has more than enough bottom end. We only want the guitar amp for its tone and sizzle.

A good place to start is the typical 50-watt combo amp. This is a staple in the amp world and there are lots of choices by lots of manufacturers. Marshall is probably the most recognized and used of these, but Vox, Fender, Crate, and Hiwatt all make 50-watt combos in various price ranges that are affordable for most musicians. On the high end you'll also find "boutique" models such as Matchless, Carr, and Alpha that offer such features as hi-fi components and hand-wiring. The common thread here is that all these are tube amps. We find that transistor amps don't work favorably with 12-string basses and can really cloud your overall tone. Tube amps open up at volume and produce very clear harmonics with warmth. The down side to a 50-watt guitar amp is that it has no trouble at all competing with the bass amp and may overpower it as you attempt to get it loud enough for the tubes to do their thing. Most amps have a gain control which will help bring in drive without being too loud, but that can sometimes get too "fuzzy" so be careful not to add too much.

One type of amp that is coming into vogue after being almost forgotten is the 18-watt combo amp. These little tone monsters can be driven way up past where other higher-powered amps can practically go to achieve that full-on tube sound at a much lower volume. This is good in that the guitar amp doesn't compete with the foundation of the bass amp for sonic space. Since you will be mic'ing the guitar amp anyway (also mic'ing or DI'ing the bass amp), the lower volume of the 18-watt guitar amp should not be a problem. Just be sure to have both amps running through your monitor so you can adjust the blending of the amps as needed.

The 18-watt guitar amp has a full history. In lieu of going deep into that I would recommend going to www.18watt.com to learn more about these wonderful amps.  One brand I would like to mention is Gabriel Sound Garage. They hand-make beautiful 18-watt amps wrapped in eye-catching yellow and black Tolex for a very unique look. Their high-quality components and hand-wiring make them a very desirable amp. You can check them out at www.gabtone.com.


You might also want to look out for a vintage Marshall 18-watt. These are the original 18-watt amps that most are patterned after, but they can be hard to find and expensive when you do find one.


If you are interested in hauling a lot of gear around (or have a personal lackey to do it for you!) you can always go big with a half or full stack. Never go with the 100-watt model as 50 watts is already more than you need. Some popular makes are Hiwatt, Orange, Reeves and Marshall. This is really overkill but it does look good on stage! One thing to remember about stacked amps is that the cabinets are closed-back design. This helps to produce better punch and fatter bottom for guitars - something you as a 12-string bassist really don't need since you're adding this amp to a bass amp that has plenty of that. This is the best argument for a smaller combo amp. The open back allows sound to travel in both directions so you get less thump and more clarity.

Keep in mind that the guitar amp is secondary to the bass amp so don't get too hung up on choosing one. Try several out and remember that you get what you pay for. There are lots of good guitar combos on the market so shop around and listen for the one that has just the right tone with a nice growl to it.