Carl Martin Dual Injection

Series / Parallel dual boost pedal 

Boost pedals are often get overlooked in favor of flashier overdrives, delays and other types of pedals, but they can be extremely useful for guitarists. Whether it's slamming the input of a tube amp on the edge of breakup to send it into full overdrive, hitting your drive and fuzz pedals harder with a boost in front of them to get even more distortion and new tones out of them, or using a boost as a handy way to increase your level by a predetermined amount for solos, boosts are often exactly the right tool you need to get the job done. Denmark's Carl Martin Guitar Effects company is obviously aware of this, and the latest release in their Chinese built Vintage Series of pedals is an interesting new boost pedal called the Dual Injection. Let's take a look at the details.

What You Need To Know

• The Dual Injection has two 12dB boosts mounted into a single 4.72" W x 3.74" D x 2.2" H enclosure. The two boosts can be run in series (one running into the next) or in parallel as if they were two separate boost pedals.

• Up to four volume levels can be pre-set; your bypassed signal, Boost 1 by itself, Boost 2 by itself, and both boosts running together.

• The nature of the Dual Injection's boosts is transparency; don't expect "treble boost" or other significant tonal colorations from it. It makes your signal louder without significantly altering it.

• Power is supplied via the Dual Injection's 2.1mm center-negative 9VDC power jack. No battery option is provided, and no power supply is included, so you'll need to budget accordingly. The power jack is located on the back of the pedal.

• There are no internal switches or trim pots inside the Dual Injection, and because it can not be powered with a battery, there's no need to open the case.

• Each of the two boosts has its own dedicated Boost knob that controls the amount of boost. Each boost also has its own individual on/off footswitch and blue LED indicator that illuminates when that boost is active. Switching is true bypass.

• There are two sets of input and output jacks on the Dual injection. On the back of the pedal on either side of the power jack are the jacks for Boost 1 input and output. On the sides of the pedal are a second set of jacks for Boost 2. Input impedance is 1M Ohm, and output impedance is 200 Ohm.

• A small toggle switch on the top of the pedal selects between series and parallel operation.

• When using the pedal in Series mode, only the top jacks are used. Boost 1 and 2 can be set to different levels and used either together, or individually, with the output of Boost 1 feeding the input of Boost 2 internally. This allows you to set up four different volume levels - the bypassed signal, Boost 1 alone, Boost 2 alone, and Boost 1 and 2 together.

• In Parallel mode lets you use the two boost pedals completely independently, and even wire them into different locations in the signal path. For example, you might use Boost 1 in front of your preamp or overdrive pedals to hit them harder for more gain and grit, while having the second boost after all of your other pedals (or as an insert in your amp's effects loop) to give you a volume boost for soloing.

Limitations

• If you flip the toggle switch to the Series position while using parallel wiring, you'll get a nasty buzz and the pedal will not function properly. This isn't the fault of the pedal, but something you should be aware of.

Conclusion

Boosts are the kind of pedals that are extremely useful, but they're usually not overly complex or sexy so they don't often generate a ton of excitement among guitarists on the various online forums. While there are other solid boost pedals on the market, and even some other dual boosts, the Carl Martin Dual Injection really does bring something new to the party with its innovative series / parallel operation and useful dual I/O configuration. It gives this pedal uncommon versatility and the ability to do more than any single boost pedal I am aware of. Having two independent boost levels in one pedal is useful, but being able to split the boosts and run them in parallel at different points in your effects chain (or with one boost at the front of your effects and the other wired into your amp's effects loop) gives the Dual Injection even more utility and flexibility. Plus it sounds good too, and there's a decent amount of boost available, and a huge amount when using them both simultaneously. All of this makes the Carl Martin Dual Injection an excellent choice for your boost pedal needs. 

Resources

Carl Martin Dual Injection series / parallel dual boost ($199.00 MSRP, $140.00 "street")

Carl Martin product web page