Looking like a Sputnik-era satellite, the Missing Link from Siegmund Guitars and Amplifiers may be the perfect way to – pardon the pun – round out a pedalboard. Encased in a very attractive polished stainless-steel half dome, the micro-tube clean-powered Missing Link is a unique effect: a transparent signal boost that does not alter the guitar’s tone.

The first thing one notices when the Missing Link is engaged (besides its cool-looking blue LED lights) is the quiet operation. According to Siegmund, the “special sauce” is a micro-tube designed to provide up to 30 dB of gain while operating smoothly under extreme conditions. This micro-tube works as a preamp to inject harmonic warmth into the signal path without adding noticeable background noise. And the military-grade micro-tube is expected to last 30,000 hours. And the setup is simple: just Volume and Tone knobs.

We tested the Missing Link through a few setups. Playing a mid-’60s Stratocaster through a non-master Marshall 50, the Missing Link gave just the right amount of overdrive for sustaining leads while retaining the guitar’s tonal qualities – qualities which sometimes disappear with an overdrive pedal.

Our favorite setup, however, was with a reissue 1959 Gibson Les Paul R9 and an original 1965 Vox AC-30 top boost. The Missing Link sounded amazing as a boost, launching the already harmonic AC-30 into the sonic heavens with gobs of sustain similar to the revered “Beano” tone. Upon rolling back the volume slightly and keeping the pickups in the middle position, the Missing Link gave the perfect blues tone, not unlike Albert King.

The Missing Link also shined as both a buffer to restore the signal of our pedal board and as a direct box, bringing some warmth into the signal chain of our digital recording setup.

Other qualities that set the Missing Link apart include the nearly indestructible shiny silver case, black Gibson-style knobs, paper oil capacitors, and carbon comp resistors. Because of the micro-tube technology, the Missing Link requires a special power supply that connects by a latching mechanism and can be easily attached to a pedalboard.

The aptly named Missing Link should be a welcome addition for players who have a good clean or mildly crunchy rhythm sound and merely want to boost the volume of their setup for solos. It’s not inexpensive, but if you are in search of a great clean boost, it is well worth the investment.

This article originally appeared in VG October 2015 issue. All copyrights are by the author and Vintage Guitar magazine. Unauthorized replication or use is strictly prohibited.