Sound — 10
Behold, the beauty of a product that does exactly what it says it should! I first played this through my Gibson 15w Goldtone tube amp run through a Marshall 1960A cab. Whith my amp turned up to about 1/4 the pedal gave me wonderful boost at all of its various levels (we'll call them zero to ten even though there are no actual numbers on it) with no tonal alterations whatsoever. I found that as I turned the amp up to half to saturate the tubes, having the pedal volume anywhere between 0-6 would give me clean boost with no other effects on the signal. With the pedal between 7 and 10 it did add a small amount of extra gain. But with the low wattage tube amp I was playing this was exactly what I expected and somewhat desired. When I plugged into a solid state amp, this didn't happen at all. It was perfectly clean signal boost with any combination pedal volume and amp volume. Most importantly, the pedal made absolutely NO popping or clicking noises when turned on or off, and NEVER added any noise to the signal even at full volume. I used it in conjunction with several different pedals, specifically a Boss metal zone MT2, a Fulltone full-Drive 2, and a Boss equalizer GE7 pedal. When placed behind these pedals it did not change their characteristics at all, only increased volume. When placed in front of the equalizer it did not effect the tone or signal either. However, in front of both the MT2 and the full-Drive, it added significant gain saturation. This definitely adds to the M.K. 4.23's versatility and possible uses. Lastly, I played two different guitars through the M.K. 4.23, a Les Paul Studio, and an American Fender Stratocaster. The tonal characteristics of each of these guitars was unaffected by the pedal at any of its volume settings. Truly wonderful!
Overall Impression — 8
My overall impression of the M.K. 4.23 Boost pedal is that it is a device made for the purist in all of us. Its overall simplicity and quality of design makes it an easy and reliable Tool for any guitar player. Whatever style you play, metal, jazz, blues, or rock it makes instantly adding volume to your sound easy and effective with relatively no negative side effects to your signal or tone, whatever that tone may be. It can also be used to enhance the general output of your guitar and thus the gain saturation of other distortion or Overdrive effect pedals. This makes it a very versatile piece of equipment. However, for all of its benefits, I think the pedal lacks the level of Precision that would make it truly invaluable whether playing Live or in the studio. Creation Audio Labs is offering 10% off all purchases over $98 to all UG members for the month of December. Simply put in UG02 into the promo code box at checkout in the online store. More details.
Reliability & Durability — 8
So I didn't put the device through any rigorous tests or anything... but on the outside at least it looks like it could take a beating. Its made of stainless steel all except for the volume knob which is plastic. I've had it for a few weeks and so far I haven't had any problems with it not functioning. I do have one very big concern, the name 'm.k. 4.23' which is on the front of the device is actually cut out of the casing, leaving a significantly large hole right on top. This might not matter to most, but if you play in bars or at parties it does NOT seem spill proof.
Ease of Use — 7
This is the first Creation Audio Labs pedal I've owned, but right away it struck me as a very effective but simple tool. The design couldn't get much simpler, it is about 4" long, 3" wide and 1" thick. I has one input and one output jack that come in through the top and it has one on/off stomp button and one volume dial. When the pedal is on there is an extremely bright white light that turns on (so bright it is clearly visible in direct sunlight, something the small LED lights on my other effects cannot boast). It comes with its own power source, but it can be run by any external nine volt adapter made for guitar pedals. There are two reasons I did not give this item a perfect ten on ease of use. The first has to do with the proximity of the stomp button to the volume dial. I have it mounted on a Pedal Pad pedal board along with all my other stomp effects. Several times I ran into the problem of my foot knocking into the volume knob when I would go to turn the pedal on, thus changing where I had it set. Now because, there is only one knob on the thing, this was very easy to fix, but still not the most convenient right when your about to take a solo. The second reason is there are no markings anywhere on the thing. The two input and output jacks aren't labeled... although I guessed which was which correctly on the first try. But more importantly there are no markers on the volume knob. This makes for a significant LACK of Precision. All the way to the left is zero db, and all the way to right is plus 24db, but in between there is no way to know exactly how much your adding to your volume. And if the volume knob does get moved out of position its hard to put it back to EXACTLY where it was. Playing Live this might not make make too much of a difference (depending on how much of a perfectionist you are), but in the studio I could see it being a serious problem.