This "patch practically anything into anything else" analog signal converter, impedance matcher, direct box, mixer and dual effects loop solves many patching challenges - both live and in the studio
$299 MSRP, $249 street
By Phil O'Keefe
We've all been there...or will wind up there eventually. Sooner or later, anyone who spends time recording, doing live sound, or working with effects pedals will run into a problem: you'll want to plug something into something else that's not compatible. Whether it's plugging a mic into a guitar stompbox or amp, or a mixing console's line output into a guitar amplifier's input for reamplification, sometimes the limitations of the inputs and outputs of the gear you want to interface locks you out of accomplishing what you'd like to do. "Adapters" that convert one plug type to another are only part of the solution, since impedance and level mismatches are often a part of the problem; leading to loading and loss of highs, weak signal levels or distorted signals that sound like they've been roasted in the depths of the Slor… okay, no more Ghostbusters references, I promise!
ENTER THE KEYMASTER
The Howard Davis and David Koltai designed Pigtronix Keymaster is a clever, yet simple to use multipurpose device that addresses these issues and many more. Pigtronix calls it a "Reamp Effects Mixer" (REM), which hints at some of its functionality, but only tells part of the story. Basically, it is a dual true bypass effects loop pedal that allows you to effortlessly connect different types of devices together, and handles the level and impedance matching automatically. The two effects loops can be run in series or in parallel, and each loop can be bypassed individually; in parallel mode, you can even "blend" or "crossfade" between the two loops, or between one of the loops and your input (dry / uneffected) signal.
INS AND OUTS APLENTY
The Keymaster (Fig. 1) offers a lot of jacks for a relatively small (5.7" X 4.7" X 1.5") pedal, but there's still plenty of room to access everything and nothing feels cramped. The right side includes a 1/4" (balanced or unbalanced) jack for input, as well as 1/4" send and return jacks for Loop A. The left side of the pedal has the balanced / unbalanced 1/4" output jack, and the send and return jacks (1/4") for Loop B.
On the top of the Keymaster, there are XLR In and Out jacks. These will work with line or mic level signals and are automatically bypassed whenever the corresponding 1/4" input or output jacks are used, but it is possible to use the XLR In and the 1/4" Out or vise versa. Also located on top of the unit are a Crossfade knob, and In Boost and Out Boost controls; which provide up to 10dB of gain going into or coming out of the loops. This allows you to fine tune your levels as needed. A small Series / Parallel toggle switch and two foot switches (complete with on / off LED indicators) for toggling the loops on and off round out the controls.
The front of the unit has a power supply input jack, as well as an expression pedal input jack. The power supply jack uses the industry standard 5.5mm "Boss style" center negative barrel plug, and although the manual warns you to only use the provided 18VDC 300mA power supply, the Keymaster will run at any DC voltage from 9V to 24V, with higher voltages providing better headroom - but for most people, the 18V power supply will provide all the headroom they'll ever need. An optional expression pedal can control the Crossfade function remotely, which lets you use your foot to "fade," blend, or control the ratio between the dry input signal and either one of the effect loops, or to crossfade between the two loops. The dual effects loops can be run in series (Loop A feeding into Loop B), or in parallel. In parallel mode, the loop signals run in two separate and parallel "paths" (much like two channels on a mixing board), and the Crossfade knob allows you to blend between the two effects loops just like you can on many DJ mixers. In parallel mode, if you have either one of the loops bypassed (and the Keymaster features true bypass switching on both loops), the Crossfade knob lets you blend the active loop with your original, dry signal.
This opens up several possibilities for mixing your dry and effected signals. For example, instead of having your signal go straight through a fuzz pedal, you can blend your clean and fuzz tones together, giving you new sounds. This is possible with whatever pedal or pedals you have inserted into the effect loop; parallel compression being one of my personal favorite uses of this feature. You can even fade between two different sets of effects by using both loops simultaneously in parallel mode.
Fig. 1. The Keymaster provides a variety of input and outputs in a compact, rugged enclosure.
WHAT DOORS WON'T IT OPEN - AND WHAT SHOULD YOU AVOID OPENING?
So, what's missing? Not much. Blatantly disregarding the back panel sticker's warnings about voiding the warranty, I opened up the Keymaster and had a look inside. Hey it's my job as a reviewer to take such risks so that you don't have to. You can satisfy your curiosity and still keep your warranty intact by having a look at Figure 2. The layout and wiring are clean, with molex connectors used for the wiring connections to the surface mount component populated PCB. This should simplify servicing and disassembly in the unlikely event that it is ever needed. As I suspected, there's no transformer isolation, and there is no hidden trimpots or phantom power switch for use with condenser microphones. Actually, the Keymaster really isn't designed to be a microphone preamp, so it's unfair to ding it for lacking phantom power… but there is enough headroom available so that you can actually insert a mic preamp into either one of the loops to provide you with sufficient gain should you need more than the Keymaster provides. Usually, I had no problems with plugging a moving coil dynamic or tube condenser mic right into the XLR In jack and forgoing the mic preamp in the loop. The lack of transformer isolation might be an issue if you want to use the Keymaster to feed two amplifiers simultaneously, but good isolation transformers tend to be relatively expensive, and including one would have added considerably to the Keymaster's price, and would have required a larger enclosure in order to fit it in. You can patch one in "downstream" of one of the "send" jacks if you're using it for this application and are running into ground loop issues. Diamond, GigRig and others make pedal sized transformer isolation units if you find yourself in need of one.
Fig. 2. The Keymaster's clean interior... don't open yours or you'll void your warranty.
My good friend, songwriter and guitarist extraordinaire John McGill, pointed out that you can't switch the sequence of the two loops when operating in series mode - Loop A always feeds into Loop B; while you can always repatch to get around this, a second toggle switch to "flip" the order of the loops when in serial mode might be a nice addition. Additionally, the ability to invert the phase of one of the two loops would also be a nice addition and would prove handy when using the Keymaster to run a pedal with inverted polarity in one loop in parallel with the far more common non-inverting pedals on the other loop.
WHAT KINDS OF THINGS CAN YOU DO WITH IT?
There are a lot of different ways you can use the Keymaster. Here are some examples:
THE DOOR IS WIDE OPEN
If you run into an interconnect challenge, or if you can think of a creative gear patching scenario, chances are the Keymaster can help you do exactly what you have in mind. I kept finding new ways to use it, and I suspect I still have not exhausted its possibilities. The pedal is very quiet and was 100\\% reliable and trouble free during my testing. The impedance matching worked seamlessly, and I never noticed anything getting loaded down, no matter how I had things patched together.
While I filed this review under the "recording category," I had a difficult time deciding where to put it because the Keymaster really belongs in multiple categories. In spite of its "guitar pedal" format, I see it as being a must-have item for not only guitarists and bassists, but also for singers, keyboard and horn players, and recording enthusiasts and studios of all levels and sizes. It's priced comparably to a good quality active direct or reamping box, and can do the job of both - and then some. It's simply a great problem solver and creative resource, and it will effortlessly solve problems that you WILL run into sooner or later, while allowing you new creative flexibility in the ways you use the equipment you already have. When a product offers this much utility and usefulness, solves this many problems and headaches, and does it at a more than reasonable price point, it's a no-brainer. It gets a big thumbs up from me - very highly recommended!